acceleration
MOI4M01
GANIL-SPIRAL2 facility - Recent achievements and upgrades
1
The Grand Accélérateur National d'Ions Lourds (GANIL) is a multi-beam facility, unique in intensity, particle types and simultaneous production. The Sys-tème de Production d’Ions Radioactifs en Ligne de 2ème génération (SPIRAL2) facility covering an excep-tionally broad intensity range, from nanoamperes to milliamperes further enhances the scientific opportu-nities of the laboratory. The first proton beams from the LINAC were produced in 2019 and is operational for physics experiments since 2022. The cyclotron operation and the initial operational challenges and lessons learned in the first years of operation of the LINAC and Neutrons For Science (NFS) facilities are presented. The physics program at GANIL-SPIRAL2 is briefly presented. The ongoing upgrades and devel-opments essential to sustain increasingly ambitious pure and applied science programs are also presented.
Paper: MOI4M01
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOI4M01
About: Received: 15 Apr 2026 — Revised: 14 May 2026 — Accepted: 16 May 2026 — Issue date: 22 May 2026
MOI4M03
Commissioning progress of the ESS linear accelerator
8
The European Spallation Source (ESS) is in the final stages of commissioning its linear accelerator (linac), which will deliver a high-power proton beam for neutron production. The commissioning process involves progressive testing of subsystems, including the ion source, radio-frequency quadrupole (RFQ), and superconducting cavities, to ensure stable and reliable beam operation. Key challenges include beam dynamics optimization, machine protection, and high-power RF system integration. Within this presentation an overview of the commissioning status, key milestones achieved, and expectations for the first beam on target, marking a significant step toward full facility operation could be given.
Paper: MOI4M03
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOI4M03
About: Received: 13 May 2026 — Revised: 19 May 2026 — Accepted: 21 May 2026 — Issue date: 22 May 2026
MOI1T01
Project status and R&D efforts for Super Tau-Charm Facility
14
The Super Tau-Charm Facility (STCF) was proposed as a third-generation circular electron-positron collider in the energy range of 2-7 GeV (CoM) and with a luminosity greater than 5*10^34 cm^-2s^-1 @4 GeV, aiming to explore charm physics and tau physics in the next decades. This presentation will introduce the facility design and R&D efforts for STCF, including the design goal, accelerator and detector schemes, and key technological R&D efforts, with focus on the accelerator. Under the financial support of the key technology R&D project by the local governments and other national funding agencies, the STCF accelerator team including international collaborators has completed the conceptual design of the accelerator, and started the technical design. The accelerator consists of a full-energy injector consisting of multi-section linacs and a positron accumulator ring and a double-ring collider with the crab-waist collision scheme. Key physics and technological challenges will be addressed. Ongoing R&D efforts and progresses will be summarized. The project planning will also be given. International collaboration is much welcome.
Paper: MOI1T01
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOI1T01
About: Received: 12 May 2026 — Revised: 21 May 2026 — Accepted: 22 May 2026 — Issue date: 22 May 2026
MOI1T02
Linear collider studies and prospects
19
Linear e⁺e- colliders can provide a broad physics programme spanning centre-of-mass energies from the Z pole to the TeV scale, enabling precision measurements of the Higgs boson, top quark, and the electroweak sector with polarised beams. Two mature accelerator technologies are under development for a possible linear collider facility (LCF) at CERN beyond the HL-LHC: the superconducting RF (SCRF) approach embodied by the ILC as developed for hosting in Japan, and the proposed normal-conducting high gradient RF (NCRF) two-beam scheme of CLIC. Both options are described in detailed documents contributed to the European Strategy for Particle Physics Update (ESPPU) process. Beyond an initial implementation in the 250-380 GeV range, upgrades in energy and/or luminosity enabled by R&D on cool copper structures, higher gradient SCRF, energy recovery and plasma wakefield options can be considered. This paper summarises the status of the studies and associated technology developments, potential long-term upgrade paths, and key implementation parameters including cost, power, and sustainability assessments.
Paper: MOI1T02
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOI1T02
About: Received: 13 May 2026 — Revised: 19 May 2026 — Accepted: 20 May 2026 — Issue date: 22 May 2026
MOO1T03
Progress towards a muon collider
34
The muon collider concept promises a unique opportunity to push the energy frontier in particle physics. The large muon mass suppresses synchrotron radiation and allows the acceleration and collision of the beams in rings and the use of technology more similar to hadron colliders. Muons are point-like, in contrast to protons, and thus can achieve a similar physics reach with less energy, allowing for a more compact machine. However muons have a lifetime of only 2.2 microseconds at rest. The muon beam thus needs to be cooled and accelerated rapidly to maximise the luminosity, which creates several technology challenges. The International Muon Collider Collaboration is implementing an intense R&D programme to address these challenges and to develop the concept maturity. The presentation will highlight the key challenges, summarise the progress of the work and the proposed R&D plan for the next decade.
Paper: MOO1T03
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOO1T03
About: Received: 13 May 2026 — Revised: 18 May 2026 — Accepted: 18 May 2026 — Issue date: 22 May 2026
MOI7M02
HTS technology development for energy efficient magnets in PSI Large Research Facilities
45
Over the past decade, the Magnet Section at the Paul Scherrer Institute (PSI) has developed extensive expertise in superconducting magnet design, construction, and testing, forming the foundation for SMILE (Superconducting Magnets to Improve Large Research Facilities Efficiency) - a proposed R&D initiative that brings together PSI experts and international partners. SMILE’s primary goal is to enhance magnet performance while significantly reducing energy consumption and CO₂ emissions across PSI’s large research facilities. This presentation outlines the future roadmap for advancing High Temperature Superconductor (HTS) technology at PSI’s High Intensity Proton Accelerator (HIPA) complex. A key focus is the development of cryocooler-based HTS magnets for both DC and ramping applications, addressing the unique challenges of operating conduction-cooled HTS tapes in dynamic field environments. Additionally, a critical research area focuses on understanding and mitigating radiation-induced degradation in HTS materials, essential for magnets operating near high-intensity targets. This combined focus on performance enhancement, energy efficiency, and radiation resilience aims not only to reduce PSI’s power consumption and environmental footprint, but with meaningful contributions impacting the research related to the industrial use of the HTS magnets.
Paper: MOI7M02
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOI7M02
About: Received: 09 May 2026 — Revised: 20 May 2026 — Accepted: 21 May 2026 — Issue date: 22 May 2026
MOO7M03
Machine learning techniques for design of complex accelerator magnets
58
The design of multipole and other magnets for accelerators is typically an iterative process in which the magnet geometry is optimised for the required beam dynamics properties. Modelling the field for a given geometry can be computationally expensive, so exploring the parameter space can be a time-consuming procedure. The task is particularly challenging when complex field properties are needed (for example, in magnets with several multipole components or with longitudinal field variation). Combined function magnets with several multipole components are particularly useful in accelerators with tight spatial constraints such as an X-ray Free Electron Laser (XFEL). Surrogate models using neural networks can provide a way of rapidly generating possible magnet geometries for given field or beam dynamics requirements. In this contribution, we discuss how machine learning tools may be used to improve the efficiency of the design process for complex accelerator magnets, and present results from a case study based on a combined function magnet for the beam spreader in a future XFEL.
Paper: MOO7M03
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOO7M03
About: Received: 12 May 2026 — Revised: 15 May 2026 — Accepted: 21 May 2026 — Issue date: 22 May 2026
MOP1022
The Linear Ghost Collider: an efficient Higgs Factory
108
A 550 GeV centre-of-mass Higgs factory is presented, the Linear Ghost Collider (LGC). Acceleration and deceleration are performed within SRF linacs where the bunches trans- ported are net neutral, comprising equal charges of electrons and positrons, termed ghost bunches. Within these, one charge partner accelerates, and the other decelerates. En- ergy is recovered after a collision, and all particles recycled. An accompanying paper - Ghost Collider (GC) - introduces this concept. LGC comprises an alternative configuration to GC that eliminates turn-around arcs. This enables a large re- duction in energy lost to synchrotron radiation, and in bunch degradation, in comparison to GC. Two variants of LGC are presented: a pulsed version realisable with proven SRF technology with instantaneous luminosity $35 \times 10^{34}$ cm$^{−2}$ s$^{−1}$ @ 100 MW electrical power; and a continuous-wave (CW) version based on expected parameters for thin-film Nb$_3$Sn-on-copper SRF technology, capable of $348 × 10^{34}$ cm$^{−2}$ s$^{−1}$ @ 160 MW electrical power.
Paper: MOP1022
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP1022
About: Received: 11 May 2026 — Revised: 18 May 2026 — Accepted: 21 May 2026 — Issue date: 22 May 2026
MOP1041
Beam-delivery challenges for plasma-wakefield accelerators
153
Plasma-wakefield acceleration offers a promising path towards a next-generation collider, but poses significant beam-delivery challenges. We present initial designs for final-focusing systems capable of transporting beams from the plasma-based-collider concepts, ALiVE and HALHF, each with distinct beam dynamics constraints. For ALiVE, where the beams are intrinsically round, we demonstrate an increase in L_1%/L_𝑡𝑜𝑡 from 3.6% to 27%, and explore ultra-compact FFS configurations reflecting the potential for significantly reduced collider lengths. For HALHF, where the beams feature large horizontal emittance to alleviate the burden on the plasma linac, we show that a global chromaticity correction scheme reduces aberrations to within 20% of the design beam size at 375 GeV, and identify synchrotron radiation as the dominant limitation at higher energies.
Paper: MOP1041
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP1041
About: Received: 13 May 2026 — Revised: 18 May 2026 — Accepted: 22 May 2026 — Issue date: 22 May 2026
MOP1045
Vertical deformation of the 10 TeV muon collider ring for neutrino flux mitigation
165
Muons offer several advantages for circular colliders: as leptons, they allow for high-precision and similar physics reach as larger hadron colliders, while their higher mass suppresses the synchrotron radiation that limits circular electron colliders. The main challenge of muon colliders is the short lifetime of muons. Muon decay generates an intense neutrino flux emitted in a narrow cone tangential to the beam trajectory. To keep the resulting radiation at the Earth’s surface negligible, dedicated mitigation strategies are required. Besides minimizing straight sections, the main mitigation measure under consideration is to periodically deform the beam trajectory and collider ring vertically to spread the neutrino flux over a larger area. This can be achieved by installing all ring magnets on a mechanical system allowing to move them regularly and adding horizontal magnetic field components. However, this affects the collider optics, especially since it introduces vertical dispersion that must be properly matched across the lattice. The present work presents the first studies on the impact of such vertical periodic deformation on beam dynamics and collider performance.
Paper: MOP1045
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP1045
About: Received: 13 May 2026 — Revised: 21 May 2026 — Accepted: 22 May 2026 — Issue date: 22 May 2026
MOP1062
Operational loss limit in the off-momentum collimation section of the LHC
197
At the Large Hadron Collider (LHC) at CERN, nearly 3600 ionization chambers composing the Beam Loss Monitoring (BLM) system are distributed along the ring and at each collimator. They are responsible for protecting the machine against energy deposition originated from beam losses by requesting the beam extraction when the measured signals are above certain predetermined thresholds. The setup of these thresholds is complex and requires a combination of simulations and measurements. In preparation for the High Luminosity-LHC (HL-LHC) era, the bunch intensity has been pushed from 1.4e11 to 1.8e11 protons during the LHC Run 3. With this higher intensity, more power is required in the radio-frequency (RF) cavities to capture the beam and reduce beam losses due to off-momentum particles, in particular at the start of the energy ramp. The present limitation on maximum allowed beam losses on the off-momentum collimation region is around 60kW and comes from the theoretical quench limit of the matching quadrupole magnets in cell 6 (Q6) which is based on the initial LHC magnet quench models. Supported by simulations, a dedicated machine development test took place in 2025 to assess in two steps if 200kW and 500kW beam losses from off-momentum particles could be sustained in the off-momentum collimation section without quenching the Q6 or any other magnets. This paper describes the procedure of the test carried out and discusses the main findings in terms of the power loss reached and the recorded loss patterns.
Paper: MOP1062
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP1062
About: Received: 13 May 2026 — Revised: 21 May 2026 — Accepted: 21 May 2026 — Issue date: 22 May 2026
MOP1070
Inverse modeling of spatially coherent random vibrations for assessing impact on particle beam dynamics in circular accelerators
221
Vibrations cause emittance growth, beam misalignment at the interaction point, and particle loss, limiting accelerator performance. Ground motion and technical noise are characterized by absolute power spectral density (PSD) and spatial correlation. Mechanical support resonances, which amplify these effects, are determined via transfer functions. A method to generate random displacements from these vibration characterizations was developed using one- and two-dimensional inverse Fourier transforms. The generated displacements accurately reproduced the input PSD spectra and spatial correlation, as verified by Welch's estimation. As a demonstration, the displacements were applied to X-suite beam dynamics simulations of the FCC-ee booster lattice to assess emittance growth and beam offsets. The method enables iterative optimization of mechanical supports and beam transport systems to minimize vibration impacts.
Paper: MOP1070
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP1070
About: Received: 12 May 2026 — Revised: 19 May 2026 — Accepted: 21 May 2026 — Issue date: 22 May 2026
MOP1075
Experimental Study of Charging and Mobilisation of Dust Grains on Beam Screen Surfaces
237
Beam losses caused by interactions between the circulating beam and dust grains have been observed at many particle accelerators, leading to premature beam dumps, quenches of superconducting magnets, and vacuum pressure bursts. At some facilities, these events have a significant impact on the overall accelerator performance. The mechanisms by which dust grains detach from vacuum-chamber surfaces and enter the beam are not yet fully understood; one possible process is charge build-up on the grain followed by lofting due to the beam potential. We present an experimental study of the charging and mobilisation of silica dust on accelerator-relevant surfaces: Cu, co-laminated Cu, laser-treated Cu, NEG-coated substrates and samples treated with VacSeal, a silicone-based resin widely used to seal vacuum leaks. The observations provide input for dust-dynamics simulations and studies of beam losses.
Paper: MOP1075
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP1075
About: Received: 11 May 2026 — Revised: 22 May 2026 — Issue date: 22 May 2026
MOP1091
Challenges of the Long Shutdown 3 for the LHC: from preparation to execution
266
The Long Shutdown 3 (LS3) of the Large Hadron Collider (LHC) represents a pivotal phase in the lifecycle of CERN’s accelerator complex. The unprecedented complexity of LS3 arises from the challenge of integrating the High-Luminosity LHC (HL-LHC) upgrade, together with multiple key projects, extensive maintenance and consolidation activities, into a single coherent schedule with a fixed duration of 47 months. Achieving this goal requires precise orchestration of interventions and effective management of resources shared across different facilities. This paper first outlines the LS3 preparation framework for the LHC, with an emphasis on the adopted methodology to accomplish the LS3 objectives and the preparation of the LHC schedule. It also investigates the main challenges associated with LS3 execution and presents the strategies and tools envisaged to address them. A unifying environment for monitoring and reporting is introduced—a platform that integrates interactive dashboards designed to streamline the progress visualisation and ensure a reliable reporting throughout the LS3 period.
Paper: MOP1091
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP1091
About: Received: 13 May 2026 — Revised: 19 May 2026 — Accepted: 21 May 2026 — Issue date: 22 May 2026
MOP1092
FERMI Linac upgrade: commissioning experience of the first S-band High-Gradient Module
270
The FERMI seeded free-electron laser (FEL), located at the Elettra laboratory in Trieste, is a 4th-generation light source operating in the vacuum ultraviolet to soft X-rays range. In order to extend the FEL spectral range to shorter wavelengths, an increase in the linear accelerator (linac) energy from 1.5 to 2.0 GeV is required. S-band HG module is designed to fulfil the upgrade requirement of 30 MV/m accelerating gradient with the breakdown rate (BDR) in the range of low 10-8 bpp/m. One HG module consists of two HG structures, 3.0 m in length, and one Spherical Pulse Compressor (SPC). The 1st HG module is successfully commissioned at the FERMI linac up to an accelerating gradient of 27 MV/m with the BDR of around 5 x 10-8 bpp/m. In this paper, we share the commissiong experience of the HG module from installation, conditioning, high power operation, and commissioning with the beam.
Paper: MOP1092
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP1092
About: Received: 15 Apr 2026 — Revised: 30 Apr 2026 — Accepted: 16 May 2026 — Issue date: 22 May 2026
MOP1094
Impact of rapid acceleration on beam dynamics in the rapid-cycling synchrotrons of a muon collider
273
Circular muon colliders offer a promising route to multi-TeV center-of-mass energies with high luminosity. The baseline design for the high-energy complex includes a chain of pulsed synchrotrons covering energies from 63 GeV to 5 TeV. This chain combines normal and hybrid synchrotrons, using both fixed-field superconducting and pulsed normal-conducting magnets. The short muon lifetime (2.2 microseconds in the rest frame) constitutes a major challenge for the accelerator complex: attaining high luminosity requires a muon survival rate of up to 70 % throughout the acceleration chain, implying acceleration within a few milliseconds. Such rapid acceleration causes a mismatch between the beam energy in the arcs and the linearly ramped fields of the dipoles and quadrupoles. The corresponding field errors affect both the beam trajectory and optical functions. Preliminary tracking studies have been conducted to assess the emittance growth arising from these effects.
Paper: MOP1094
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP1094
About: Received: 15 Apr 2026 — Revised: 28 Apr 2026 — Accepted: 14 May 2026 — Issue date: 22 May 2026
MOP1099
Powering Concepts for Resistive Magnets in the Muon Collider Rapid Cycling Synchrotron
284
The development of a power converter for the resistive magnets of the Muon Collider Rapid Cycling Synchrotron (RCS) represents one of the most critical challenges of the muon accelerator system, given the required peak power levels in the 50–100 GW range. To address this, a modular resonant converter is proposed, consisting of several hundred identical series-connected cells interleaved with the magnets. This configuration distributes the total system voltage — on the order of tens of megavolts — evenly across the cells, while limiting the insulation voltage to ground. A key design requirement is a highly repeatable current ramp across successive pulses, with deviations at or below 100 ppm. Given the very short acceleration times, a pulse-to-pulse Iterative Learning Control (ILC) strategy is proposed to progressively meet this target. The paper presents the main converter topologies, repeatability studies, simulation results, and the proposed control approaches.
Paper: MOP1099
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP1099
About: Received: 23 Apr 2026 — Revised: 06 May 2026 — Accepted: 16 May 2026 — Issue date: 22 May 2026
MOP1117
Current status and recent development of the Xcoll-FLUKA interface
323
The Xsuite framework offers a modern environment for high-performance accelerator physics simulations. Its Xcoll module handles particle-collimator interactions using dedicated scattering routines, both built-in and external. FLUKA, a well-established Monte Carlo code, can be coupled to Xcoll, enabling detailed modelling of particle-matter interactions and support for complex geometries. This paper presents the status of the Xcoll-FLUKA interface, which provides a consistent and efficient link between deterministic beam tracking and Monte Carlo simulations. The new setup builds upon the experience gained with the previous SixTrack-FLUKA coupling, introducing a more user-friendly design and significant improvements in data exchange, modularity, and extensibility within the Xsuite architecture. Recent developments include a new filtering algorithm that improves simulation speed, a versatile definition of bent crystals, support for simplified collimator geometries represented as plain blocks of material, and an enhanced beam-beam interaction routine. These advancements represent an important step toward a flexible and performant framework for collimation and background studies in present and future accelerators.
Paper: MOP1117
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP1117
About: Received: 12 May 2026 — Revised: 19 May 2026 — Issue date: 22 May 2026
MOP1301
RCS polarization correction using information theoretic and machine learning tools
331
One of the greatest challenges for the EIC’s proposed Rapid Cycling Synchrotron will be to achieve high polarization transmission to 18 GeV. While SVD based orbit smoothing should be sufficient to achieve over 99% polarization transmission up to 10 GeV, the growth in the strength of residual imperfection spin resonances make achieving polarization transmission of 90% and above to 18 GeV more difficult when base vertical quadrupole misalignments grow larger than 100 microns. One promising approach is to deploy estimates of the vertical quadrupole misalignments using simple misalignment to BPM response matrices. Using this, the stronger imperfection spin resonances from 10 to 18 GeV can be estimated and corrected using vertical correctors. With this approach, base quadrupole misalignments of up to 200 microns can now be tolerated. However, the existence of dipole rolls limits the effectiveness of this approach since their effect on the orbit as registered at the BPMs is very similar. Here we describe a new approach which leverages machine learning methods to guide perturbations to the lattice that maximize the net Fisher’s Information and thus help increase the accuracy of imperfection spin resonance corrections.
Paper: MOP1301
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP1301
About: Received: 11 May 2026 — Revised: 18 May 2026 — Accepted: 20 May 2026 — Issue date: 22 May 2026
MOP6302
APS-RAG: A domain-aware hybrid retrieval augmented generation system for accelerator operations and knowledge synthesis
345
Effective knowledge management is essential to minimize downtime and maintain institutional memory in large-scale accelerator facilities. We present APS-RAG, a domain-aware Retrieval-Augmented Generation (RAG)\* system currently deployed at the Advanced Photon Source (APS), designed to synthesize operational intelligence and facilitate semantic data retrieval from various dispersed databases. The system consolidates over 10,000 unique documents from four live databases: the BELY scientific electronic logbook, operational Microsoft Teams chat, the Integrated Content Management System (ICMS), and Work Request system. By employing the latest frontier LLMs via Argonne’s ARGO AI platform, APS-RAG integrates a specialized query preprocessing pipeline that performs temporal parsing, domain acronym resolution, multi-query expansion, and final response generation. To ensure high precision, a hybrid retrieval architecture is utilized, combining dense vector and keyword search. The results are aggregated using Reciprocal Rank Fusion (RRF) and refined through cross-encoder reranking to maximize relevance\*\*. An 100-question evaluation dataset was built using InPars methodology\*\*\*, supplemented with qualitative user feedback. The final responses from APS RAG have inline citations embedded which displays the source document chunk and a web accessible link to the original document. Future developments include multimodal integration and agentic knowledge graph capabilities\*\*\*\*.
Paper: MOP6302
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP6302
About: Received: 13 May 2026 — Revised: 15 May 2026 — Accepted: 16 May 2026 — Issue date: 22 May 2026
MOP6303
Leveraging low-cost sensors and machine learning for pump anomaly detection in accelerator facilities*
349
The reliability of cooling systems is critical for removing substantial amounts (in megawatts) of waste heat from numerous high-power accelerator components (e.g., magnets, RF structures, power supplies) and beamline components\*. Reliance on manual inspection of hundreds of pumps is inefficient and increases the risk of costly component damage and unplanned downtime. This study introduces a real-time method for automated vibration monitoring of pumps designed to help transition facility operations from reactive to predictive maintenance. Our approach integrates (i) affordable vibration sensors\*\* and (ii) machine learning models \*\*\* for anomaly detection. We have deployed vibration sensors on the Bunch Lengthening System (BLS) Helium and water pumps, where Linux nodes aggregate and preprocess the hourly collected data. To support operational decision-making, a web-based diagnostic platform is being developed, offering real-time visualization of vibration trends against weekly baseline data and generating Short-Time Fourier Transform (STFT) spectrograms for detailed frequency analysis. Additionally, the web platform will show hourly inferences from the machine learning models on the data stream, autonomously detecting spectral anomalies indicative of mechanical faults. The integration of scalable edge data collection, advanced visualization, and unsupervised deep learning will provide a vital safeguard for maintaining operational readiness in particle accelerators.
Paper: MOP6303
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP6303
About: Received: 13 May 2026 — Revised: 15 May 2026 — Accepted: 16 May 2026 — Issue date: 22 May 2026
MOP6307
Online tuning of the NSLS-II injector using Bayesian optimization with different packages
352
The injector of the NSLS-II consists of a linear accelerator (LINAC) that accelerates the electron beam to 170 MeV, followed by a linac-to-booster (LTB) transport line and a booster synchrotron that further increases the beam energy to 3 GeV. The performance of LINAC and LTB is critical to achieve efficient and stable beam injection. Automated online tuning is an effective method to improve injector performance. In this paper, we present an automated tuning approach based on Bayesian optimization, using different software packages to optimize the LINAC and LTB. We evaluate and compare these packages based on their ability to improve injection efficiency. Our results demonstrate that Bayesian optimization can significantly enhance injector performance and show differences in performance between different packages.
Paper: MOP6307
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP6307
About: Received: 13 May 2026 — Revised: 17 May 2026 — Accepted: 20 May 2026 — Issue date: 22 May 2026
MOP6311
AI-ready lattice representation and ML optimization for the BNL booster-to-AGS transfer line
359
As part of the Nuclear Physics AI-Ready Accelerator Data (NARAD) project, Brookhaven National Laboratory is developing a demonstration use case based on the Booster-to-AGS (BtA) transfer line. We establish an AI-ready representation of the BtA lattice using the Particle Accelerator Language Standard (PALS), extended with semantic metadata linking lattice elements to control system signals and device capabilities. This NARAD-PALS model enables direct mapping between simulation, operational devices, and machine data. We implement this framework for the BtA line and demonstrate semantic device queries and control-channel resolution within the BNL Accelerator Device Objects (ADO) system. This unified representation supports integration of streaming and archived data and provides a foundation for ML-based optimization of AGS injection and cross-facility interoperability.
Paper: MOP6311
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP6311
About: Received: 12 May 2026 — Revised: 15 May 2026 — Accepted: 16 May 2026 — Issue date: 22 May 2026
MOP6312
Optimization of Fermilab Booster using a hybrid Bayesian and RL framework
363
PIP-II project will raise Fermilab Booster intensity and ramp rate. Beam losses will limit maximum power and are hard to simulate. Presently, Booster uses operator-guided empirical tuning - a challenging task due to high dimensionality, multiple objectives, critical safety constraints, and drifts. We developed a synergistic suite of Bayesian optimization (BO) and reinforcement learning (RL) tools to optimize and stabilize beam losses, including novel techniques for fast risk-aware Bayesian optimization and exploration. For initial tune-up, we performed single and multi-objective tuning using scalarized objectives comprised of critical beam loss locations, achieving significant rebalancing of losses as well as an overall improvement in transmission efficiency. To build a data-driven surrogate, active learning was used to collect data while relying on risk-aware constraints to successfully avoid beam trips. A few thousand points were collected, and a GP surrogate validated for uncertainty-aware predictions. Several off-policy RL agent architectures were trained for long term stabilization. In surrogate-based testing, SAC with BPM context and history embedding had best performance with fast and robust convergence when subjected to energy and trajectory perturbations. Experimental testing is ongoing to enable operational use.
Paper: MOP6312
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP6312
About: Received: 18 May 2026 — Revised: 20 May 2026 — Issue date: 22 May 2026
MOP6316
Hardware Aware Artificial Intelligence (HAAI): progress on realtime beam tomography reconstruction for the Fermilab Recycler using machine learning and edge processing
367
The resistive wall current monitor (RWCM) data from the Fermilab Recycler Ring (RR) is used to reconstruct the longitudinal profile of proton beams circulating in the machine. This procedure, commonly referred to as tomography, has proved to be invaluable in tuning the machine. In 2013 Recycler was re-purposed as a proton stacker and charged with implementing slip-stacking to double the intensity for the Main Injector (MI). With two slipping beams, the RWCM data from Recycler is difficult to differentiate and the tomography procedure is slow to compute using traditional means. Building upon past efforts, the Hardware Aware Artificial Intelligence (HAAI) project aims to develop a ML model to reconstruct the Recycler beam tomography in real-time and deploy this model on edge hardware. Once developed, this new streaming virtual diagnostic would be used to better track the beam parameters over larger time spans, attribute settings to beam effects, tune the machine, and provide an input into other future automatons of the machines.
Paper: MOP6316
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP6316
About: Received: 13 May 2026 — Revised: 20 May 2026 — Issue date: 22 May 2026
MOP6317
Accelerator performance drift compensation with a modified MG-GPO Algorithm
370
Performance drift has been a longstanding problem for accelerators. A desirable solution is to tune the machine slowly and gently to compensate for such drift. Previously, we presented a version of the Multi-Generation Gaussian Process Optimizer which tunes accelerator settings during operation to maintain optimal performance. In this paper, we present an improved version of the algorithm and its application test examples, in which it corrects deviations from the ideal orbit caused by a drifting orbit corrector magnet and a drifting injection kicker magnet respectively. The modified algorithm takes measures to ensure the accuracy of the Gaussian process regression models and to improve the validity of the new trial solutions. We demonstrate that this is a promising development toward using safe, real-time tuning algorithms during accelerator programs to compensate for performance drift.
Paper: MOP6317
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP6317
About: Received: 17 May 2026 — Revised: 20 May 2026 — Issue date: 22 May 2026
MOP6320
Machine learning-assisted calibration of the accelerator simulator HPSim
377
Manually calibrating the HPSim simulator to the LANSCE accelerator is time-intensive and demands substantial domain expertise. In this work, we investigate the use of machine learning (ML) to automate much of the calibration process and substantially reduce tuning time. Specifically, our focus is the calibration of the front-end of the accelerator, which involves obtaining the amplitudes and phases of the pre-buncher, main buncher and tank 1 of the drift tube linac. To get empirical data of the accelerator, we use current-phase curves obtained from absorber/collectors, both with the pre-buncher on and off. We derived features from the curves, such as standard deviation of each or average distance between them, which are then trained on ML models. By combining classical ML methods—gradient-boosted decision trees and random forests—with a state-of-the-art transformer model, we achieve a significant speed-up of the calibration process, from about a month of human expert labor to 2-3 days of mostly computational processing.
Paper: MOP6320
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP6320
About: Received: 18 Apr 2026 — Revised: 03 May 2026 — Issue date: 22 May 2026
MOP6321
Evaluating in-context learning for Advanced Light Source EPICS process variable prediction
381
Large language models are becoming increasingly relevant for accelerator operations, where they assist with common tasks like retrieving historical data, preparing analysis scripts, and coordinating multi-step procedures. At the Advanced Light Source (ALS), these operators use their personal jargon (e.g. “sector 4 beam current”) to search for the correct PV name from numerous channels, resulting in countless variations of naming conventions. Strong scores on general-purpose benchmarks do not indicate how well a model maps operator jargon to facility-specific EPICS process variable~(PV) identifiers. Building on the semantic channel-finding benchmark, we evaluate chat-based large language models on two tasks using 101 ALS expert query–PV pairs. The first probes query-level grounding via single-item testing. The assessment is executed with varying inference-time cues, scored by character-wise correspondence (Levenshstein ratio). The second probes structural understanding by requiring the model to infer character-sequence mapping from the global naming-token vocabulary under prescribed edge-count budgets. We report precision, recall, combined retrieval score (F1), and token overlap (Jaccard similarity). Applied to 27 models, these evaluations split PV retrieval from structural understanding of hierarchical naming patterns, and offer strong dependency of end-to-end PV identification on the ALS control system's naming conventions.
Paper: MOP6321
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP6321
About: Received: 15 Apr 2026 — Revised: 16 May 2026 — Accepted: 16 May 2026 — Issue date: 22 May 2026
MOP6322
Status of Osprey: A Framework for Agentic AI in Control Systems
385
Operating large-scale scientific facilities requires coordinating diverse subsystems, translating operator intent into precise hardware actions, and maintaining strict safety oversight. Language-model agents offer a natural interface for these tasks, but most existing approaches are not yet reliable or safe enough for production use. We introduce Osprey, a framework that wraps a coding agent in a control-room operator interface, a tool surface that reaches hardware through pluggable connectors for the control system used in our community, and a first-class component for natural-language search of facility electronic logbooks. The agent itself is treated as a replaceable component: operator interface, safety policy, tool servers, and connectors stay under facility control, while the agent backend can be swapped as the AI ecosystem evolves. A declarative build-profile mechanism lets each facility maintain its own configuration without forking the shared framework, keeping deployments reproducible across updates. Osprey has been deployed at several DOE accelerator facilities through the MOAT seed effort within the Genesis~Mission. This paper presents the current framework architecture and reports on the substantial evolution Osprey has undergone over the past year.
Paper: MOP6322
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP6322
About: Received: 17 May 2026 — Revised: 22 May 2026 — Issue date: 22 May 2026
MOP6330
Hybrid online optimization for hands-off tuning of the ALS injector
388
Reliable hands-off injector operation calls for fast, sample-efficient tuning under drift and competing goals (e.g., capture efficiency, energy spread, transmitted charge). We present an autotuning framework for the ALS injector combining complementary online optimizers for robust performance under strict machine-protection/operability constraints. The controller alternates methods based on objective structure and information gain, fusing diagnostics across longitudinal and transverse systems. Building on prior Bayesian and multi-objective optimization, we add extensions for tracking a moving Pareto front during drifts, time-decayed learning for stability, and global-exploration bursts to escape trade-off plateaus. On the ALS linac, we target figures of merit tied to bottlenecks (e.g., controlling beam loading-driven energy spread challenging the booster acceptance) and enforce safety via bounded steps and surrogate constraints. Initial studies show shorter tuning time and improved repeatability vs. single-method baselines while preserving capture within the booster ring’s tight longitudinal window; we summarize architecture, decision logic, and portability.
Paper: MOP6330
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP6330
About: Received: 14 May 2026 — Revised: 18 May 2026 — Issue date: 22 May 2026
MOP6336
Active supervision for AGS bunch-merging with LLM-based reinforcement learning
392
Radio-frequency (RF) bunch-merging gymnastics is used in the RHIC heavy-ion program to combine individual source pulses into single bunches with suitable intensity. Preserving intensity and emittance during these gymnastics requires careful coordination of the voltages and phases of RF cavities at several harmonic numbers, which is labor-intensive and fragile against machine drift. Recent work using a physics-based simulator of the Brookhaven Alternating Gradient Synchrotron (AGS) has shown that reinforcement learning (RL) can learn effective merge configurations. RL is data-intensive and requires many training interactions with the environment. Large language models (LLMs) have recently demonstrated the ability to extract patterns from large, noisy data and to integrate domain knowledge into the control loop, making them an attractive aid for tuning complex accelerator systems. However, domain adaptation (i.e., prompt engineering, finetuning, etc.) is always required for deploying LLM in the target domain and has not been investigated in particle accelerators. To fill this gap, we propose an active supervision framework in which the LLM-based teacher first transfers general control principles from human operators to the student agent. Then, the student agent further finetunes the control policy by interacting with the simulator/experiments with improved sample efficiency.
Paper: MOP6336
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP6336
About: Received: 13 May 2026 — Revised: 20 May 2026 — Issue date: 22 May 2026
MOP6352
Digital twin development for the NASA Space Radiation Laboratory
407
The NASA Space Radiation Laboratory (NSRL) at Brookhaven National Laboratory simulates the galactic cosmic ray space radiation environment by delivering high energy heavy ions and protons to the NSRL Target Room for radiobiology studies and microelectronics testing. The AGS Booster synchrotron delivers beams to the NSRL beamline via resonant slow extraction. NSRL tuning is difficult due to the non-linearity from slow extraction and octupoles, and the beam shape is optimized empirically by operators. To streamline and improve NSRL operations, we develop a real-time digital twin for the NSRL beam line, starting from the extraction bumps in the Booster and extending all the way to the targets. This digital twin allows users to both load live settings from the real system to the online model, and to send model suggested settings to the real machine. We demonstrate that an accurate digital twin can tremendously help improve operations at the NSRL beam line.
Paper: MOP6352
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP6352
About: Received: 11 May 2026 — Revised: 15 May 2026 — Accepted: 17 May 2026 — Issue date: 22 May 2026
MOP6357
Design of ionization profile monitors at the Integrable Optics Test Accelerator (IOTA) Facility at Fermilab
415
The Integrable Optics Test Accelerator (IOTA) at Fermilab is transitioning from an electron beam facility to a proton beam facility for studies in nonlinear accelerator optics and space-charge dominated proton beams. This project involves the commissioning and fabrication of Ionization Profile Monitors (IPMs) to enable beam profile measurements at IOTA. In general, IPMs work on principle of residual gas ionization by the beam to generate beam profile. This work focuses on a mechanical design that leverages a controlled injection of noble gases, primarily Argon, as the ultra-high vacuum of the IOTA ring provides insufficient residual gas for ionization. Efforts to understand vacuum integration to ensure compatibility with the storage ring environment, the integration of real-time data acquisition systems and the commissioning of the IPMs will be discussed. This project provides a versatile diagnostic tool, supporting IOTA’s role as a testbed for larger-scale accelerator facilities and contributing to the broader understanding of beam physics in high-intensity, high-space-charge regimes.
Paper: MOP6357
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP6357
About: Received: 19 May 2026 — Revised: 19 May 2026 — Accepted: 21 May 2026 — Issue date: 22 May 2026
MOP6372
Parallel Beam-Based Alignment at the SIRIUS storage ring
426
In fourth-generation light sources such as SIRIUS, tight orbit tolerances require accurate knowledge of BPM offsets with respect to the magnetic center of nearby quadrupoles. This work presents the implementation and experimental validation, at the SIRIUS storage ring, of the Parallel Beam-Based Alignment (PBBA) method proposed by X.~Huang. This method allows the simultaneous calibration of many BPMs. Simulations and machine experiments demonstrate that the method reduces the overall BBA time from several hours to a few minutes while preserving accuracy at the level of a few micrometers, making it practical for routine accelerator operation.
Paper: MOP6372
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP6372
About: Received: 13 May 2026 — Revised: 20 May 2026 — Issue date: 22 May 2026
MOP6374
SPEAR3 booster response matrix measurement
430
In this paper, we present the orbit response matrix (ORM) measurements for the SPEAR3 booster obtained using a set of Libera Spark ERXR beam-position processors. The turn-by-turn acquisition capability of these processors enables continuous tracking of the beam trajectory throughout the full energy ramp prior to injection into SPEAR3. This dataset provides sufficient resolution to extract the booster’s optical functions and to perform ORM-based fitting of lattice errors such as quadrupole strength deviations and magnet roll angles in the Accelerator Toolbox (AT) model. The resulting refinements to the machine model have contributed to improved understanding and mitigation of beam-loss mechanisms, thereby enhancing the beam capture from the linac-to-booster (LTB) transport line and injection efficiency into SPEAR3.
Paper: MOP6374
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP6374
About: Received: 13 May 2026 — Revised: 18 May 2026 — Issue date: 22 May 2026
MOP6375
Integration of X-Ray Diagnostics into Fast Orbit Feedback for Local Source Stabilization at NSLS-II
434
We present an accelerator-based X-ray beam stabilization approach that integrates X-ray beam position monitor (XBPM) signals into the fast orbit feedback (FOFB) system at NSLS-II. A high-speed electrometer and fiber-optic data link were developed to transmit XBPM position data to the storage-ring feedback controller at a 10 kHz rate. On the accelerator side, the XBPM signal is incorporated into the FOFB infrastructure as a virtual beam position monitor, allowing photon beam motion to be corrected through the electron beam orbit using fast corrector magnets. Experimental tests demonstrate suppression of dominant beamline vibration peaks near 27 Hz and 120 Hz when the feedback is enabled. These results demonstrate the feasibility of integrating photon diagnostics into accelerator feedback systems for improved X-ray beam stability and motivate the development of unified photon–electron feedback architectures for routine operation.
Paper: MOP6375
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP6375
About: Received: 06 Apr 2026 — Revised: 14 May 2026 — Accepted: 16 May 2026 — Issue date: 22 May 2026
MOP6380
Facility-wide monitoring and early detection of failures at LANSCE
442
Accelerator complexes contain tens of thousands of interdependent components, and aging infrastructure amplifies the risk of equipment faults and costly, unscheduled shutdowns. At the Los Alamos Neutron Science Center (LANSCE), we are developing a data-driven framework that flags developing problems early enough to address them during scheduled maintenance, thereby improving reliability and increasing beam availability for users. Our approach analyzes all available signals within a subsystem to learn the facility’s “normal” operating envelope and to detect subtle deviations that precede failures. Unlike the current warning scheme, it captures hidden correlations among parameters and generates interpretable indicators of abnormal behavior. Predictions are validated against historical control-room log records. We report progress on three fronts: (i) extending anomaly prediction from a single beamline to all major LANSCE subsystems; (ii) expanding data archiving capacity by an order of magnitude to support broader coverage and longer look-back windows; and (iii) developing operator-facing algorithms that both warn of emerging anomalies and localize likely problem elements along the beamline. Together, these advances are designed to shift maintenance from emergency response to planned intervention, reducing downtime and enhancing overall facility performance.
Paper: MOP6380
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP6380
About: Received: 11 May 2026 — Revised: 19 May 2026 — Accepted: 20 May 2026 — Issue date: 22 May 2026
MOP6381
Exploring causes of Beam Loss at CEBAF
446
At Jefferson Lab, the Continuous Electron Beam Accelerator (CEBAF) features a unique design with two linear accelerators and two arc sections allowing for multiple turns of the electron beam, as well as four experimental end stations. This topology leads to increased beam losses, especially in the spreader and recombiner regions connecting the arcs to the LINACs and in the extraction regions connecting the experimental end stations to the accelerator. These losses result in equipment activation and operational interruptions. Recent upgrades to the facility’s diagnostic systems, including the addition of xenon ion chambers, have provided higher-resolution data regarding these loss events. Building on this improved observational capability, we are developing a simulation framework using optics codes and the Geant4-based BDSIM to model beam extinction and halo formation in these regions. This work aims to correlate simulation results with experimental data to isolate the causes of beam loss and inform future machine tuning strategies. We present a summary of conclusions drawn from recent operational studies and outline a plan to model the beam loss and validate the simulations.
Paper: MOP6381
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP6381
About: Received: 12 May 2026 — Revised: 16 May 2026 — Issue date: 22 May 2026
MOP6389
High-power test and system integration of direct RF sampling based LLRF control and monitoring system for S-band accelerating structures
457
High precision Low-level RF (LLRF) control and monitoring systems for future particle accelerators will be a significant technical challenge as the requirements in performance, flexibility and affordability become increasingly stringent. We have developed an RF system-on-chip (RFSoC) based next generation LLRF (NG-LLRF) for S-band accelerating structures, which samples and synthesizes the RF pulses directly without the analog mixers used for traditional LLRF systems. The platform delivered considerably better performance than the requirements of the targeted applications, such as the upgrades for Next Linear Collider Test Accelerator (NLCTA) and test facilities at SLAC. As part of the upgrade program, we also developed a custom solid-state amplifier (SSA) to deliver RF pulses at desired power level of the klystron. The integration of the LLRF with SSA and the high-power test facility could be challenging. The power levels and RF pulse stability at each stage of the high-power RF drive system need to be optimized to deliver the desired RF performance. In this paper, the integration procedure and the test and characterization results at each stage of integration will be summarized, analyzed and discussed. This integration is an essential step for the full deployment of the NG-LLRF system to the test facilities and accelerators in different frequency bands.
Paper: MOP6389
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP6389
About: Received: 18 Apr 2026 — Revised: 14 May 2026 — Issue date: 22 May 2026
MOP6390
Automated tuning techniques at TRIUMF for the ARIEL era
461
Implementing automated tuning techniques has been a priority at TRIUMF, driven by the need to support the significant increase in RIB availability expected with the new Advanced Rare Isotope Laboratory (ARIEL). This efficiency boost will facilitate a broad spectrum of research in nuclear, particle, and astrophysics. This work outlines the shift from manual tuning to an automated approach for optimizing beamline transport. We utilize the predictive digital twin, Model Coupled Accelerator Tuning (MCAT), to compute transport and accelerated beam tunes, while Bayesian Optimization for Ion Steering (BOIS) handles beam orbit correction. BOIS treats steering as a black-box optimization problem, maximizing beam current based solely on direct measurement. By combining MCAT and BOIS, this method offers a more efficient, physics-grounded tuning process, with potential applications for facilities beyond TRIUMF.
Paper: MOP6390
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP6390
About: Received: 13 May 2026 — Revised: 20 May 2026 — Issue date: 22 May 2026
MOP6393
Longitudinal phase space diagnostics for the AGS
465
The Collider-Accelerator Department (C-AD) maintains and operates an injector complex that provides beams for the Relativistic Heavy Ion Collider (RHIC) and the future Electron-Ion Collider (EIC). Beams traveling in accelerator rings are grouped in bunches, where their profiles can be measured and displayed by a Wall Current Monitor (WCM). By analyzing those WCM signals, conclusions can be made about the beam quality, and necessary tuning can be performed accordingly. Meanwhile, it will be very helpful to have the beam property parameters available while doing beam experiments, such as the longitudinal emittance, momentum spread, bunch length, etc. In this work, we present such a software tool that will process and publish those parameters in real time, based on live machine data and WCM signals. Those parameters will also be logged to the system and will be available for later retrieval and analysis.
Paper: MOP6393
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP6393
About: Received: 12 May 2026 — Revised: 20 May 2026 — Issue date: 22 May 2026
MOP6394
Progress in the development of the community Particle Accelerator Language Standard (PALS)
469
The Particle Accelerator Language Standard (PALS) is a community effort to create an open standard to promote lattice information exchange for particle accelerators. PALS development is a community-wide international effort involving accelerator physicists from multiple institutions. While it started as a lattice standard for beam dynamics simulations, it is now being extended to support other particle accelerator activities, in particular accelerator operation. With new accelerators that are becoming more complex, larger collaborations and the increasing imprint of artificial intelligence in all accelerator activities (from design to operation to workforce development), the imperative for a common, standardized accelerator ontology has been transitioning from “nice-to-have” to “must-have”. We will present the status of the project, its relations to other projects, including to two of the particle accelerator projects of the newly announced US DOE Genesis Mission: the Multi-Office Accelerator Team (MOAT) project and the Nuclear physics AI-Ready Accelerator Data (NARAD) project.
Paper: MOP6394
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP6394
About: Received: 14 May 2026 — Revised: 15 May 2026 — Issue date: 22 May 2026
MOP6395
Genetic optimizations of RF cell profile using Superfish
473
Important RF cell parameters such as the shunt impedance 𝑅𝑠, the quality factor 𝑄, and the ratio of accelerating to peak field, depend on the cell geometry. Thus, it is desirable to optimize the cell profile to optimize the performance of the cell. The use of B-splines to optimize cell profiles with a genetic algorithm has been demonstrated. The RF field solver Superfish, however, does not support defining cell geometries using B-splines. Here we discuss a similar approach using only linear and elliptical segments supported by Superfish to define the cell geometry, making it possible to carry out genetic optimizations with Superfish.
Paper: MOP6395
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP6395
About: Received: 13 May 2026 — Revised: 17 May 2026 — Issue date: 22 May 2026
MOP6614
The development of novel beam diagnostics for low-MeV protons
489
In charged particle therapy, high energy layer switching times prolong beam delivery time, limiting treatment efficiency and accuracy. The TURBO (Technology for Ultra-Rapid Beam Operation) project aims to build a low-energy (0.5-3 MeV) demonstrator beamline for proton therapy with a large momentum acceptance (±42%), enabling rapid delivery over the full clinical energy range, alleviating this bottleneck. Novel beam diagnostic instrumentation is required to monitor key parameters of the beamline constructed for the University of Melbourne’s Pelletron accelerator, which operates at low energies and high current densities. We develop a pepper-pot mask-based method to measure beam phase space distribution and quantify the emittance, and a multi-layer Faraday cup (MLFC) to measure energy distribution. This work now enables the completion of the beam shaping section, and integration of a fixed-field, closed-dispersion beam transport section, key next steps toward assessing TURBO’s potential to shorten beam delivery times.
Paper: MOP6614
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP6614
About: Received: 13 May 2026 — Revised: 19 May 2026 — Issue date: 22 May 2026
MOP6621
Investigation of diagonal-cut plane BPM performance in the CSNS RCS
497
Diagonal-cut plane Beam Position Monitors (BPMs) are used to measure the transverse position of the proton beam in the Rapid Cycling Synchrotron (RCS) at the China Spallation Neutron Source (CSNS). Significant transverse beam position offsets were observed at several locations along the RCS. These offsets are potentially attributable to abrupt changes in the cross-section of the upstream and downstream vacuum ducts, BPM calibration constants determined at a single frequency on the calibration system, and limitations in the position calculation algorithm. To assess the impact of the sudden changes in beam duct aperture, numerical simulations were performed. Additionally, BPMs were recalibrated on a test bench to evaluate the influence of abrupt cross-sectional changes in the BPM and vacuum ducts on the observed offsets at different frequencies.
Paper: MOP6621
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP6621
About: Received: 12 May 2026 — Revised: 19 May 2026 — Issue date: 22 May 2026
MOP6624
Optimization of DCCT magnetic core matching using unsupervised machine learning techniques for high-precision beam current measurement
504
DC Current Transformers (DCCTs) are essential instruments for non-interceptive beam current measurement in particle accelerators. The zero-flux modulation principle demands exceptional symmetry between paired magnetic cores to achieve sub-$\mu$A offset stability. Conventional core matching based on static magnetic parameters provides only an engineering approximation, as it neglects the dynamic magnetization behavior under AC modulation. This paper presents a novel approach employing unsupervised machine learning techniques applied to 6 dynamic magnetic parameters ($\mu_\mathbf{a}$, $\delta$, $B_\mathbf{r}$, $B_\mathbf{m}$, $H_\mathbf{c}$, $H_\mathbf{m}$) measured at 50 kHz sinusoidal excitation for 19 Fe-based nanocrystalline cores. Principal Component Analysis (PCA) reduces the feature space while preserving $89.64\%$ of total variance. An adaptive multi-objective K-Means strategy successfully isolates anomalous specimens ($K=2$), while a density-based evaluation framework partitions the remaining operational cores into 5 highly homogeneous sub-groups. This two-tier matching scheme enables a physically rigorous core pairing that accounts for real-world dynamic magnetization and domain wall losses under actual DCCT operating conditions.
Paper: MOP6624
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP6624
About: Received: 13 May 2026 — Revised: 21 May 2026 — Issue date: 22 May 2026
MOP6627
Development of Analog Electronics for the Beam Loss Monitoring System in the Superconducting Section of the CSNS II Linac
508
The analog electronics for the Beam Loss Monitoring (BLM) system in the superconducting section of CSNS II is mainly used for signal conditioning of the output signals from BLM beam loss detectors. For the BLM electronics of CSNS I, a single-channel transimpedance circuit was designed. The overall response time of the detector, transmission cable, and electronics is approximately 150 μs, with a focus on high-sensitivity design, which fails to meet the 10 μs response time requirement for machine protection in the superconducting section of CSNS II. Referring to the design of the LHC BLM electronics, a Charge-to-Frequency Conversion (CFC) circuit has been developed to split the charge generated by beam loss ionization into cumulative charge packets Qt with a fixed time interval T. Machine Protection System (MPS) triggers are generated by comparing the count from a counter with a calibrated unit-time count, and a high-speed ADC samples the frequency waveform to calculate the beam loss value through algorithms.
Paper: MOP6627
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP6627
About: Received: 12 May 2026 — Revised: 19 May 2026 — Accepted: 20 May 2026 — Issue date: 22 May 2026
MOP6629
Application of Wall Current Monitor at CSNS Rapid Cycling Synchrotron
511
Two sets of Wall Current Monitors (WCMs) have been installed in the Rapid Cycling Synchrotron (RCS) of the China Spallation Neutron Source (CSNS) to fulfill three core beam diagnostic objectives: synchronous measurement of longitudinal bunch shapes across both macro and micro scales, accurate calculation of longitudinal emittance, and effective diagnosis of beam instabilities. This article focuses on the comprehensive discussion of the entire WCM system (probe and DAQ system) and its practical application during CSNS-RCS beam commissioning. The WCM system has performed quite well during the beam commissioning over the past years.
Paper: MOP6629
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP6629
About: Received: 13 May 2026 — Revised: 20 May 2026 — Issue date: 22 May 2026
MOP6635
Design of the high-speed, high-precision average beam current and lifetime measurement system
519
This paper presents a high-speed, high-precision sys-tem for measuring average beam current and lifetime, addressing the low data refresh rates of existing systems that fail to capture rapid beam dynamics. A comprehen-sive performance analysis identifies key error sources, including the beam probe, data acquisition card, elec-tromagnetic interference, and quantization noise. Exper-imental validation at the HLS shows that with a 0.5 μA resolution probe, the system achieves measurement ac-curacy better than 1 μA at a 1 Hz update rate and 2 μA at 100 Hz. This high-speed, high-precision current meas-urement enables rapid and accurate lifetime determina-tion. The system provides a critical tool for real-time monitoring of injection efficiency and beam stability, and offers essential data support for analyzing beam loss mechanisms and beam dynamics.
Paper: MOP6635
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP6635
About: Received: 12 May 2026 — Revised: 15 May 2026 — Accepted: 18 May 2026 — Issue date: 22 May 2026
MOP6650
Experimental verification of energy dependence in a CNT wire monitor for beam profile measurements in the J-PARC Linac
546
The J-PARC linac accelerates a 50 mA H⁻ beam up to 400 MeV for user operation. To mitigate emittance growth caused by space-charge effects, transverse beam profiles are measured using wire scanner monitors (WSMs) for routine beam tuning. Tungsten is generally used as the wire material. However, the WSMs employ carbon nanotube (CNT) wires in the low-energy region between the RFQ and DTL, because the beam energy is low as 3 MeV and the thermal load is substantial. CNT wires were introduced in 2017 as a more heat-resistant alternative, and since then they have operated without replacement due to beam-induced damage, demonstrating excellent durability. In this study, we report beam profile measurements obtained with the CNT WSM at various beam energies.
Paper: MOP6650
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP6650
About: Received: 13 May 2026 — Revised: 19 May 2026 — Issue date: 22 May 2026
MOP6670
Development of the beam permit system for the RAON accelerator
579
The Beam Permit System (BPS) has been implemented as a software-level permit and verification layer for the Rare isotope Accelerator complex for ON-line experiments (RAON), a heavy-ion accelerator being commissioned at the Institute for Basic Science (IBS) in Korea. While the Machine Protection System (MPS) provides fast hardware signal-based protection against beam-induced equipment damage, the BPS complements it by checking software-level conditions such as EPICS Input/Output Controller (IOC) availability, Process Variable (PV) consistency, and operating-mode correctness. By combining IOC monitoring, configuration checks, and mode-aware permit logic, the BPS ensures that beam delivery is allowed only when all required operating conditions are satisfied. Commissioning tests in the currently operational RAON section (up to SCL3) show that the BPS identifies hardware or software inconsistencies and inhibits beam extraction when necessary, ensuring that beam delivery occurs only under verified and safe operating conditions. This paper presents the design and implementation of the RAON BPS and summarizes the first commissioning results of this combined hardware–software protection approach.
Paper: MOP6670
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP6670
About: Received: 18 May 2026 — Revised: 19 May 2026 — Issue date: 22 May 2026
MOP6687
Overview of the accelerator operation at China Spallation Neutron Source since its official opening
604
The China Spallation Neutron Source（CSNS） is the first large-scale pulsed spallation neutron source in China and the fourth of its kind in the world. It is a large multidisciplinary user facility. The facility passed national acceptance and officially opened for operation in 2018. It has been in operation for seven years. During this period, the beam power has continually increased, and both the beam runtime and availability have gradually improved. In the 2023-2024 period, it achieved a maximum beam on target time of 5,433 hours and the highest beam availability of 97.4%, which are the best among similar international facilities. This article will comprehensively introduce the operational performance of the accelerator over the past seven years, including annual beam runtime, beam availability, and statistics on hardware system downtime. Additionally, it will briefly discuss some measures taken to enhance operational reliability, including hardware upgrades, software optimizations, and maintenance strategies.
Paper: MOP6687
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP6687
About: Received: 13 May 2026 — Revised: 18 May 2026 — Issue date: 22 May 2026
MOP6697
Neural network-based amplitude feedforward control algorithm for LLRF systems
617
In free-electron laser facilities, the amplitude-phase stability of the microwave pulses driving the electron beam is a key factor determining beam energy spread. Aiming at the long bunch train operation mode, this paper proposes a neural network-based amplitude feedforward control for low-level radio frequency (LLRF) systems to suppress intra-pulse amplitude fluctuations. The algorithm has been validated at the output of a solid-state amplifier (SSA): under four randomly selected vector modulator (VM) output configurations, the average intra-pulse amplitude flatness (RMS) was reduced from 1.208% to 0.398%, and the average peak-to-peak variation was reduced from 4.683% to 1.353%, demonstrating a significant compensation effect.
Paper: MOP6697
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP6697
About: Received: 15 Apr 2026 — Revised: 18 May 2026 — Accepted: 20 May 2026 — Issue date: 22 May 2026
MOP6701
Application of Pyapas in PWFA
628
The Plasma Wakefield Acceleration (PWFA) experimental platform consists of two beamlines. Beamline 1 (BL1) transports the electron-positron beams from the BEPCII linear accelerator to the experimental station, with a beam energy of 2 GeV. Beamline 2 (BL2) is a linear accelerator featuring an energy of 150 MeV and a bunch charge exceeding 5 nC. Currently, both beamline accelerators have entered the beam commissioning phase. Pyapas, an independently developed High-Level Application (HLA) by the Institute of High Energy Physics (IHEP), has been successfully applied to beam commissioning of high-energy light sources. We have achieved the successful porting and application of Pyapas in the beam commissioning of the PWFA linear accelerators.
Paper: MOP6701
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP6701
About: Received: 13 May 2026 — Revised: 22 May 2026 — Issue date: 22 May 2026
MOP6703
Machine-learning surrogate modeling of the RAON LEBT beamline
631
We present a machine-learning surrogate model for the RAON LEBT that enables fast prediction of beam centroids at multiple diagnostics. A dataset of TRACK simulations spanning relevant steering-magnet and electrostatic-quadrupole settings is used to train fully connected neural networks. The surrogate model reproduces the underlying beam dynamics with high accuracy while providing orders-of-magnitude faster evaluation. This approach supports rapid orbit studies, optimization, and data-driven beam control in the RAON front-end transport system.
Paper: MOP6703
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP6703
About: Received: 11 May 2026 — Revised: 21 May 2026 — Issue date: 22 May 2026
MOP7001
Upgrade of the arcing suppression system for the waveguides in the European XFEL
634
When planning the European XFEL, the decision was made to avoid using SF6 in the waveguide systems. Instead, air was used at slight to high overpressure. When slight overpressure is used, the air is also in motion. The air flow travels from the RF source towards the cavities and is released again before the coupler. This ensures that, in our non-gas-tight waveguide system, the air quality in the waveguides corresponds to the air quality supplied by the compressor. Particles and ionised air that could promote arcing are blown out. Originally, the air pressure was generated by local compressors and the air used came from the ambient atmosphere. Now, the accelerator’s central compressed air system is utilised. Locally, only the newly developed controls for air pressure and flow remain. The advantage of the central compressed air supply lies in the significantly better air quality and greater operational reliability.
Paper: MOP7001
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP7001
About: Received: 07 May 2026 — Revised: 17 May 2026 — Accepted: 17 May 2026 — Issue date: 22 May 2026
MOP7009
Characterization of the four-quadrant X-band cavity prototype for the ASTERIX project
648
The ASTERIX project, hosted by the INFN–LNF, seeks to achieve the first demonstration of a practical, meter-scale X-band RF accelerating structure suitable for operational linear accelerators (>100 MV/m accelerating gradient). The goal is to produce innovative RF structures to qualify as part of the world-wide scientific collaboration (SLAC/CERN/INFN-LNF/KEK/Tsinghua) for R&D in the accelerator development and high-power testing of innovative cavities with high gradients. The structure is composed of four-quadrants (“open-type”), made of hard copper, joined and vacuum sealed by using TIG welding (“braze-free” technique) through a cost-effective and robust manufacturing. The full-structure RF design, in single-bunch operation mode, was carried out with the 3D numerical simulation codes Ansys HFSS and CST Microwave Studio. In this paper, we report on the engineering of the full-structure prototype optimized for low RF power measurements and initial mechanical tests in order to validate the quadrant straightness and alignment, the TIG welding process, the vacuum tightness; etc. The proto-type was fabricated with lower precision of geometric dimensions and more relaxed mechanical tolerances.
Paper: MOP7009
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP7009
About: Received: 12 May 2026 — Revised: 17 May 2026 — Issue date: 22 May 2026
MOP7011
SSPA efficiency improvement studies at ALBA in the framework of the RF2.0 project
655
ALBA is a 3rd generation synchrotron light source and is member of the RF2.0 project, which aims to reduce the carbon footprint of this kind of large research facilities by improving its efficiency, reliability and operational sustainability. In this contribution, we present the work done together with our partner COMMTIA, that has developed the Adaptive Power and Digital Control (APDC) for a 5 kW 1.5 GHz SSPA amplifier, which enables a real-time efficiency optimization by changing dynamically the drain voltage of the transistors while delivering RF power. This is done in two different ways: either the SSPA sets the desired voltage as function of the output power or the Digital Low Level RF system sets the voltage to the SSPA by means of a digital signal. This maximizes the efficiency at each point of operation, ensuring stable performance under the varying load and thermal environments common on accelerator facilities. The laboratory measurements indicate substantial improvements in efficiency, that comes with the cost of the SSPA linearity gain reduction. These developments show how flexible solid-state RF systems can satisfy demanding high-performance requirements while lowering the energy consumption and carbon footprint of accelerator infrastructures.
Paper: MOP7011
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP7011
About: Received: 13 May 2026 — Revised: 17 May 2026 — Accepted: 17 May 2026 — Issue date: 22 May 2026
MOP7012
Power couplers conditioning and multipacting simulations for the ESS- Bilbao ARGITU RFQ
658
The ARGITU RFQ at ESS-Bilbao is a 352.2 MHz, 4-vane RFQ that will accelerate protons from 45 keV to 3.0 MeV. The RF power comes from a modulator/klystron by rectangular waveguides that end in coaxial lines that are finished by the two loop power couplers. The couplers are made of copper and no brazing has been used in their production. For this reason, the vacuum/air window is made of PEEK material attached by mechanical pressure to the copper structure. For the initial stages of the ARGITU RFQ, the duty cycle will not rise above 1%, so these couplers were designed with no active cooling. This paper summarizes the conditioning setup and focuses on the RF, thermal and multipacting simulations used to define safe high-power conditioning limits.
Paper: MOP7012
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP7012
About: Received: 12 May 2026 — Revised: 19 May 2026 — Accepted: 21 May 2026 — Issue date: 22 May 2026
MOP7018
X band Linac machine design for very high energy electron therapy
673
Very high energy electrons (VHEE) are a potential future modality in the field of radiotherapy. They have garnered considerable interest because they possess a unique combination of several properties including: being capable of deep tissue penetration (>30 cm), relative insensitivity to tissue inhomogeneities and being well suited to FLASH therapy. FLASH is the use of ultra-high dose rates which have been shown to reduce cell death in healthy tissue whilst maintaining toxicity to tumours. Recent studies indicate that higher energy beams produce less scattering and more precise dose delivery up to at least 250 MeV. This paper provides a design for a 250 MeV linac with dose rates exceeding 100 Gy/s in a 10 cm × 10 cm wide field size. The design is centred on a bi-periodic, π/2 mode, normal conducting, standing wave, accelerating cavity which emphasises stability. A gradient of 100 MV/m has been chosen to achieve the compactness potentially required to fit the accelerator in a hospital setting. To this end, 11.9942 GHz X-band technology has been selected which, along with extensive cell geometry optimisation, has produced a shunt impedance of > 95 MΩ/m and whilst minimising surface electric and magnetic fields.
Paper: MOP7018
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP7018
About: Received: 12 May 2026 — Revised: 16 May 2026 — Accepted: 17 May 2026 — Issue date: 22 May 2026
MOP7019
Optimized low-cost, high-efficiency cavity design for 100–500 MeV proton linacs
677
Over the past four decades, the accelerator community has made substantial progress in advancing both normal-conducting and superconducting RF cavity design and fabrication technologies. As the global demand for new accelerator facilities continues to increase, the development of low-cost, high-efficiency RF cavities has become essential for ensuring the long-term sustainability of accelerator science. In this work, we introduce a new RF cavity concept, designated Alansa-PL, developed by the ISIS Linac Group. This design provides a simpler and more efficient alternative to conventional coupled-cavity structures. Preliminary studies indicate that the Alansa-PL cavity exhibits enhanced performance for proton accelerators in the 100–500 MeV energy range. The conceptual design and electromagnetic modelling of the cavity, operating at 972 MHz with β = 0.5, are presented and discussed in this paper.
Paper: MOP7019
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP7019
About: Received: 15 Apr 2026 — Revised: 21 May 2026 — Accepted: 21 May 2026 — Issue date: 22 May 2026
MOP7023
Current status and progress of design and commissioning of HELIAC cavities
688
The HElmholtz LInear ACcelerator (HELIAC) at GSI is a superconducting continuous-wave (cw) LINAC, designed to deliver heavy-ion beams to user experiments at GSI. Building on the successful integration, commissioning and operation of the first cryomodule CM1 utilizing cavities CH0, CH1, and CH2, current efforts emphasize on fabrication and testing of the next series: CH3 - CH8. Cavities CH3–CH8 have been designed and validated through dedicated advanced simulations. The manufacturing of components for CH3 and CH4 cavities now undergoing electron beam welding. The targeted design resonance frequency of 216.816 MHz will be fine-tuned via buffered chemical polishing (BCP) and compensation procedures to address manufacturing tolerances. The cavity design and tuning strategy will be presented in this contribution.
Paper: MOP7023
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP7023
About: Received: 18 May 2026 — Revised: 19 May 2026 — Accepted: 22 May 2026 — Issue date: 22 May 2026
MOP7034
Status of the High Q-High G R&D activities on SRF cavities at INFN LASA
706
INFN LASA started an R&D activity dedicated to the development of knowledge needed to understand how to improve SRF cavity performances to reach High Q and High G values to accomplish the sustainability and cost reduction requests, as needed for the future large particle accelerators. This R&D activity, funded by INFN, is also enriched by synergies with other LASA activities as PIP-II low beta cavity production, the participation to ILC Technology Network, and by the LASA experience in SRF cavity industrialization developed during the large-scale production of the Eu-XFEL and the ESS SRF cavities. First results obtained on 1.3 GHz single and multi-cell cavities, and the status of the upgraded LASA infrastructures for Vertical Test are presented and discussed.
Paper: MOP7034
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP7034
About: Received: 13 May 2026 — Revised: 18 May 2026 — Accepted: 22 May 2026 — Issue date: 22 May 2026
MOP7035
R&D activities in view of PIP-II LB650 cavity production
710
A joint LASA–Fermilab activity is in progress to study the impact of key surface processing steps on the performance of LB650 superconducting cavities in view of future series production. Among the several cavity preparation steps, electropolishing (EP) and mid-temperature heat treatment are considered the most critical and require specific optimization for the LB650 geometry. Single-cell and 5-cell cavities are used as test prototypes to investigate the effects of EP and mid-temperature bake at 350 °C. Vertical RF tests are performed at Fermilab after EP and after the mid-T bake under identical conditions. The ongoing program aims to provide insight into the evolution of Q₀ and accelerating gradient along the processing sequence. Preliminary observations and results are here presented.
Paper: MOP7035
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP7035
About: Received: 12 May 2026 — Revised: 22 May 2026 — Issue date: 22 May 2026
MOP7036
SRF cavity detuning characterization by continuous wavelet transform: a time-frequency analysis
714
Sustainability is a key issue for both current and future particle accelerators. Superconducting RF cavities with high loaded quality factors play an important role in not only lowering the energy demands of particle accelerators but also the initial investment in RF amplifiers. But the narrow bandwidth associated with this high loaded quality, makes the need to minimize cavity detuning critical to maintain stable and efficient operation. In this context, characterization of microphonics detuning is essential, as it is a major error source, for implementation of effective mitigation schemes to reduce peak and rms RF power requirements. Here we analyze SRF cavity detuning using the Continuous Wavelet Transform (CWT). Unlike conventional Fourier-based approaches, the CWT enables localized time-frequency decomposition, making it well-suited for identifying transient features that influence cavity behavior. Applying the CWT to measured detuning signals from a TESLA cavity at HoBiCaT testing facility at Helmholtz-Zentrum Berlin allows us to identify dominant detuning frequencies and track their evolution over time. The resulting time-frequency maps offer a more comprehensive understanding of the underlying mechanical environment and can support the development of more robust detuning mitigation and compensation strategies for SRF systems.
Paper: MOP7036
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP7036
About: Received: 15 Apr 2026 — Revised: 14 May 2026 — Accepted: 22 May 2026 — Issue date: 22 May 2026
MOP7037
Additional installation effort for the 3MW readiness at ESS
718
Since the last installation campaign, additional High-Beta (HB) cryomodules (CM) have been tested and qualified Ready-for-Installation (RFI) at the ESS Test Stand. Their installation was planned for the summer’25, right after the first Beam On Dump (BOD) commissioning phase and a complete warm-up of the accelerator. The number of HB CM has raised to 11 out of 21 allowing for a potential maximum power of the Linac of 3 MW. This paper will present the lessons learned from the previous phase as well as the necessary measures taken in order to install 6 cryomodules in a RP controlled area in only 3 months.
Paper: MOP7037
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP7037
About: Received: 13 May 2026 — Revised: 15 May 2026 — Issue date: 22 May 2026
MOP7049
1.6 MW, 144 MHz solid state power amplifier for ELSA electron linac
739
The 19 MeV electron linear accelerator ELSA at CEA DAM has been in operation for 30 years. A renovation of the RF system was necessary to improve the reliability of the system. The second part of the renovation concerns the 144 MHz RF amplifier supplying power to the photo-injector. The former tetrode based amplifier has been replaced by a 1.6 MW Solid State Power Amplifier delivered by Ampegon company. One of the challenges was to design a compact amplifier to keep the same footprint. This paper will present the amplifier, the tests and the commissionning.
Paper: MOP7049
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP7049
About: Received: 11 May 2026 — Revised: 15 May 2026 — Issue date: 22 May 2026
MOP7050
Conceptual design of a 0.2 MW pulsed 140 GHz gyroklystron amplifier and studies towards 1 MW operation for accelerator applications
742
Exploration of accelerator technologies in the millimeter-wave regime offers a promising route to achieve extremely high accelerating gradients. Owing to the high shunt impedance and short filling times of mm-wave accelerating structures relative to conventional S- and C-band systems, GV/m-level accelerating gradients become attainable. Mm-wave accelerator concepts are therefore of strong interest for applications including future linear colliders, charged-particle therapy, compact X-ray free-electron lasers (XFELs), and ultrafast electron diffraction (UED). We present the conceptual design of a pulsed 140 GHz gyroklystron amplifier intended as an RF power source for mm-wave accelerator systems. The interaction circuit adopts a two-cavity configuration composed of an input cavity, a drift section, and an output cavity. The electron beam is generated by a triode-type magnetron-injection gun (MIG) that provides operational flexibility, enabling adjustment of beam parameters and stable performance across a broad operating range. Design details of the MIG and the two-cavity interaction structure will be presented.
Paper: MOP7050
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP7050
About: Received: 12 May 2026 — Revised: 18 May 2026 — Issue date: 22 May 2026
MOP7054
LIPAc RF system: on the versatile use of photomultipliers
749
Modern photomultipliers (PMs) are affordable, highly sensitive, easy to operate, compact, and sufficiently robust for demanding accelerator environments. In systems such as the Linear IFMIF Prototype Accelerator (LIPAc) in Rokkasho, Japan, whose radiofrequency (RF) subsystem delivers over 2 MW of RF power distributed among all the accelerating cavities, these characteristics make PMs particularly effective for monitoring components prone to multipacting and micro-discharge. The light produced by these phenomena is detected even at very low levels, enabling detailed investigation and fast triggering of interlocks to prevent damage. At LIPAc, the superconducting RF (SRF) accelerator currently being commissioned is fully equipped with PMs. PMs have also been successfully used in a temporary test bench* and in lightweight setups to assess the attenuation of aging optical fibers. Finally, prospects for upgrading the existing RF quadrupole (RFQ) arc detector will be presented.
Paper: MOP7054
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP7054
About: Received: 12 May 2026 — Revised: 18 May 2026 — Issue date: 22 May 2026
MOP7066
Prototyping of a tunable permanent magnet quadrupole
782
Within the Research Facility 2.0 (RF2.0)* project, one of the objectives is the development of novel permanent-magnet technologies and refurbishment strategies aimed at reducing energy consumption in accelerator facilities. In this context, ALBA, ELYTT, and HZB are jointly developing a tunable quadrupole prototype based on permanent magnets, conceived as a demonstrator for next-generation, energy-efficient magnet systems. The prototype is designed to achieve high-gradient focusing while drastically reducing power consumption relative to conventional electromagnets, eliminating the need for large coils and water cooling. Its compact architecture also eases integration into densely packed storage-ring lattices. Tunability is provided through a hybrid approach combining movable soft-iron elements and small auxiliary coils, offering a wide operational range with minimal energy demand. This contribution presents the electromagnetic and mechanical design of the prototype, the assembly strategy, and the current status of the manufacturing and testing.
Paper: MOP7066
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP7066
About: Received: 15 Apr 2026 — Revised: 18 May 2026 — Issue date: 22 May 2026
MOP7069
Absolute pulsed-mode, long-duration integral field instrumentation using a multi-sensor approach
790
A recent upgrade of the CERN Super Proton Synchrotron (SPS) quadrupole magnet measuring system enables high relative accuracy on the order of $10^{-5}$ over cycle sequences up to 800 seconds long, as needed for machine-learning based modeling and control of hysteresis effects in the frame of the Efficient Particle Accelerator (EPA) initiative. A new fluxmeter assembly integrates multiple arrays of PCB induction coils with Hall probes and local coils for in-situ cross-calibration, while new FFMM (Flexible Framework for Magnetic Measurements) C++ classes provide automation of complex excitation current cycles, data reduction and database storage. A Python data processing pipeline uses Kalman filters to fuse multiple sensors, correcting for integrator drift. This enables absolute measurements even without traditional Nuclear Magnetic Resonance (NMR) probes, which operate only in uniform fields.
Paper: MOP7069
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP7069
About: Received: 11 May 2026 — Revised: 16 May 2026 — Accepted: 17 May 2026 — Issue date: 22 May 2026
MOP7070
Static and dynamic field characterisation of the super proton synchrotron bending magnets
794
To ensure precise control of field quality in normal-conducting accelerator magnets, it is essential to develop models that accurately represent magnetic hysteresis during operational cycles. This study focuses on the dipole magnets of the CERN Super Proton Synchrotron (SPS) and investigates how variations in operational cycles produce different hysteresis and dynamic patterns in the integrated main magnetic and higher-order field multipoles. A combination of various magnetic field measurement systems was employed to evaluate the magnetic field quality, enabling direct observation of history dependence and reproducibility. Three regimes are identified: a history-dependent reversal curve along the ramp, eddy-current settling during end-of-ramp transients, and a rate-independent transfer function at the plateau. The analysis covers the integrated dipole and sextupole components, distinguishing rate-dependent eddy current effects from quasi-static hysteretic contributions. Two pre-cycle patterns currently used in operation are compared: a \SI{200}{GeV} cycle and a \SI{26}{GeV} cycle introduced in 2026 within the CERN Efficient Particle Accelerator (EPA) initiative. The aim is to provide a quantitative single-magnet assessment of this change of operation.
Paper: MOP7070
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP7070
About: Received: 11 May 2026 — Revised: 15 May 2026 — Accepted: 17 May 2026 — Issue date: 22 May 2026
MOP7074
Integrated HTS CCT magnet and beam pipe : a proposal for the FCC-ee final focus quadrupole QC1L/R1
805
High Temperature Superconductors (HTS) and Canted Cosine Theta (CCT) technologies have been extensively studied in recent years, particularly for high-field accelerator magnets. Their application to next-generation particle accelerators is especially promising. This article presents the combination of these two technologies for the FCC-ee Final Focus (FF) quadrupole QC1L/R1, including its integration within the Machine-Detector Interface (MDI). We detail the specific design, mechanical specifications, and manufacturing process—driven by the coil’s significant curvature angle—as well as the cryogenic test strategy and results. Additionally, we describe the design of a cooled beam pipe adapted to the magnet and cryostat constraints.
Paper: MOP7074
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP7074
About: Received: 12 May 2026 — Revised: 22 May 2026 — Issue date: 22 May 2026
MOP7083
Field Quality of MQXFB Quadrupoles for HL-LHC
820
This paper presents the main results of the magnetic measurements performed on the available MQXFB quadrupoles at room and cryogenic temperature. The measurement program, carried out during the different stages of the magnet assembly and by using different instruments such as the rotating-coil and stretched-wire systems, allows an early identification of the field errors and a comprehensive characterization of the field quality. A fine tuning of the low-order multipoles is achieved by magnetic shims using iron inserts, which provides a means for improving the field quality of some magnets. The transfer function, the field harmonics, and the effects of superconductor magnetization and iron saturation are reported. In addition, a warm-to-cold extrapolation method is developed for the prediction of the integrated gradient at 1.9 K and nominal current, with an accuracy within 5·10-4, allowing a proper sorting of the magnets at an early stage and before the final cold test. In conclusion, all the MQXFB magnets tested so far meet the field-quality requirements for the HL-LHC, and the adopted measurement and correction strategy has proven to be effective for the series production.
Paper: MOP7083
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP7083
About: Received: 12 May 2026 — Revised: 16 May 2026 — Accepted: 16 May 2026 — Issue date: 22 May 2026
MOP7088
Numerical-experimental comparative research of titanium foil grades for accelerator output windows
832
The stress-strain state of titanium foils used for accelerator output windows was investigated with various foil thicknesses and titanium grades. Initial material data included deformation diagrams, densities, Young’s moduli, and Poisson’s ratios for each grade. Experimental studies were performed to validate the central displacements of Titanium Grade 2 foils. Measurements were conducted using a Hexagon precision measurement machine to determine the effective friction coefficients between titanium and two contacting materials: stainless steel 304L and oxygen-free copper. The latter was obtained via fitting the displacement curves of the initial simulations and experimental measurements conducted. These coefficients were subsequently incorporated into refined numerical simulations to obtain a more accurate representation of the stress–strain state within the sealing region of the output window assembly. Comparative analyses of the simulation results were carried out for all selected titanium grades. The advantages and limitations of each grade were evaluated in terms of mechanical performance, deformation behavior, and suitability for use in accelerator output window applications.
Paper: MOP7088
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP7088
About: Received: 31 Mar 2026 — Revised: 15 May 2026 — Accepted: 16 May 2026 — Issue date: 22 May 2026
MOP7089
SEY reduction using ultrathin TiN/NbN multilayers for accelerator applications
836
Multipacting and electron cloud formation remain major limitations for the performance of modern particle accelerators. In superconducting radio-frequency (SRF) cavities, multipacting can prevent stable cavity operation and restrict achievable accelerating gradients. In positively charged particle machines such as the LHC, the build-up of electron clouds results in beam instabilities, vacuum degradation, and additional heat loads on the cryogenic systems. Reducing the secondary electron yield (SEY) of vacuum-facing surfaces is therefore a key strategy to mitigate these effects. To mitigate these effects, several strategies have been proposed, in particular the deposition of thin films designed to reduce the secondary electron yield (SEY) of the relevant surfaces. We investigated the SEY behaviour of ultrathin TiN/NbN multilayers, with particular attention to the influence of both the number of layers and the TiN/NbN stacking sequence. Multilayers composed of individual 3 nm films were deposited by PVD to probe interfacial effects and possible electronic confinement phenomena. SEY measurements performed before and after electron conditioning reveal a dependence on the multilayer architecture. One particular multilayer configuration achieves a significantly reduced SEY, reaching 0.98 after conditioning.
Paper: MOP7089
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP7089
About: Received: 07 May 2026 — Revised: 16 May 2026 — Accepted: 16 May 2026 — Issue date: 22 May 2026
MOP7095
Particulate study of NEG pumps irradiated in the CEBAF tunnel
843
Non-evaporable getter (NEG) pumps are being used to maintain ultra-high vacuum in the beamline of superconducting radio-frequency (SRF) accelerators, such as the Continuous Electron Beam Accelerator Facility (CEBAF) at Jefferson Lab. Because of the sensitivity of the performance of SRF cavities to particulate contamination, it is important to evaluate the integrity of the NEG material after exposure to high radiation during beam operation. The particulate from two NEG pumps based on ZAO getter alloy was measured with a particle counter in a clean-room. The pumps were assembled onto a hermetically sealed setup which was placed in the CEBAF tunnel. The setup was exposed to 24 h beam operation for ~230 days. The total gamma-rays dose measured on the test setup was ~1.6 Mrad. The total neutron dose measured at ~75 cm of the test setup was ~11 krad. The particulate count from the two pumps was measured again in the clean-room after irradiation. Whereas an increase of particulate counts was measured, compared to before irradiation, subsequent measurements indicate the absence of systematically loose particulate. The pumping speed of one of the irradiated pumps was also measured to be consistent with that of a non-irradiated one, corroborating the absence of significant damage to the ZAO NEG material due to irradiation.
Paper: MOP7095
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP7095
About: Received: 08 May 2026 — Revised: 18 May 2026 — Accepted: 22 May 2026 — Issue date: 22 May 2026
MOP7120
KIT superconducting undulator and magnet developments - overview and state of the art R&D on HTS technology
904
Undulators are widely used in synchrotron storage rings and free-electron laser facilities. With the advent of low-temperature superconductors (LTS), a new generation of superconducting undulators (SCUs) emerged, including the recent new THz LTS undulator for FLUTE. At KIT, state-of-the-art magnetic and cryogenic measurement capabilities — provided by the Magnet and Cryogenics Facilities (MCF) and the Accelerator Technology Platform (ATP) — form a foundation for the development and characterization of these systems. Building on this experience, KIT is now advancing magnets and undulators based on high-temperature superconductors (HTS), aiming for compact, sustainable, energy- and resource-efficient solutions. These activities are driven by in-house research and providing the full value chain of HTS technology from tape development via structuring to prototypes and tests in real-world environments at KIT. In this contribution, we provide an overview of our current developments and the supporting experimental infrastructure.
Paper: MOP7120
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP7120
About: Received: 11 May 2026 — Revised: 15 May 2026 — Accepted: 17 May 2026 — Issue date: 22 May 2026
MOP7142
The CYREN project: Refurbishment of the GANIL cyclotrons facility
971
For over 40 years, the GANIL facility has been supplying stable beams (carbon to uranium, 60 keV/A to 95 MeV/A) and low- and high-energy radioactive ion beams for fundamental, applied and industrial research from a set of 5 cyclotrons. Since 2010, due to the SPIRAL2 construction and compliance projects associated with the French safety regulations, the cyclotrons maintenance and refurbishment were reduced to a bare minimum, and as a consequence the failure rate increased over the years. Present scientific and industrial demand for GANIL cyclotrons beams, and projection for future demands over the years to come, request GANIL to guarantee the operation over the next 20 years or more. Therefore an ambitious renovation program, the CYREN (Cyclotrons Renovation) project, was launched in 2024. This article covers the progress of this project, detailing the challenges, partly due to the diversity of the different installations, the uniqueness of the equipment and the sometimes aging, implemented technologies. The project covers a broad variety of equipment from the 5 cyclotrons, beam lines, the associated experimental caves, building infrastructures, technical utilities and the safety, security and radiation protection systems.
Paper: MOP7142
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP7142
About: Received: 13 May 2026 — Revised: 19 May 2026 — Accepted: 20 May 2026 — Issue date: 22 May 2026
MOP7143
Updates on the sustainability improvements of the Karlsruhe Research Accelerator
974
The thermal well system to support the cooling plant of the accelerator test facility Karlsruhe Research Accelerator (KARA) at the Karlsruhe Institute of Technology (KIT) is in test operation after about one year of commissioning. To avoid any impact on the environment, follow the governmental regulations, and document different aspects and operation statistics, KIT developed a special robust and reliable data handling pipeline. We describe the implementation of the data archiving strategy, as well as the experiences gained and statistics on e.g. power reduction from the first year of commissioning of the thermal wells. Furthermore, our plans for improvement and extension of KARA's efforts towards sustainable operation are presented.
Paper: MOP7143
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP7143
About: Received: 12 May 2026 — Revised: 16 May 2026 — Accepted: 17 May 2026 — Issue date: 22 May 2026
MOP7145
EURO-LABS: integrating European Research Infrastructures for physical sciences
980
The European Laboratories for Accelerator Based Sciences (**EURO-LABS**) programme advances research frontiers by providing unified Transnational Access (**TNA**) to leading European Research Infrastructures (**RI**s) in the Physical Sciences. It brings together the nuclear physics, accelerator, and detector R\&D communities to foster collaboration and stimulate synergies. With 33 partners across Europe, EURO-LABS forms an integrated network of RIs ranging from small-scale test facilities to large European Strategy Forum on Research Infrastructures (ESFRI). The access provided enables research at the technological frontiers of accelerator and detector development, supporting the exploration of new physics concepts and opening new avenues in both fundamental and applied research --- from optimizing reactor operation to mimicking stellar reactions. EURO-LABS actively promotes diversity and inclusion, offering equitable access to researchers across nationalities, genders, ages, and career stages, while strengthening Europe’s collaborative scientific landscape. EURO-LABS started in September 2022 and will conclude in August 2026. This contribution will present highlights of the project’s activities, along with notable experiments and supported research carried out at the participating facilities.
Paper: MOP7145
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP7145
About: Received: 13 May 2026 — Revised: 20 May 2026 — Issue date: 22 May 2026
MOP7146
Unifying efforts in electrical safety for an accelerator complex
984
Large research facilities with continuously evolving electrical installations and many stakeholders often face unique challenges in implementing electrical safety. The Electrical Safety Project at CERN aims to standardize methods and processes in order to improve electrical risk management during maintenance and operation of the CERN accelerator complex. The project focuses on several axes for improvement. Two of these are the clear identification of the limits of responsibility along the powering supply chain among different teams that provide equipment for accelerators, and the reconstruction of the electrical dependencies between equipment from the source to the load. After introducing the project with its challenges, the paper will report on the progress made by ESP in these two specific fields and on the proposed methodology towards their long-term implementation.
Paper: MOP7146
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP7146
About: Received: 04 May 2026 — Revised: 20 May 2026 — Accepted: 20 May 2026 — Issue date: 22 May 2026
MOP7147
Infrastructure Worksite Coordination : lessons learned from the HL-LHC case study
987
The High-Luminosity Large Hadron Collider (HL-LHC) project at CERN is a major upgrade aimed at increasing LHC’s instantaneous luminosity by a factor of five and integrated luminosity by ten. This involves extensive new infrastructure, including underground galleries, access shafts, and surface facilities, pushing accelerator technology beyond current limits. Managing this complexity requires centralized coordination through a worksite hub that enables real-time communication, adaptive planning, and stakeholder support from conception to commissioning. A combined top-down and bottom-up planning approach ensures alignment with long-term objectives while addressing operational challenges. Dedicated planning tools support milestone tracking, resource management, and coordination of activities. Operational efficiency relies on safety, schedule adherence, and rapid response to technical issues. The approach demonstrates strong adaptability, reactivity, and collaborative problem-solving. Overall, this paper highlights the importance of flexible on-site coordination, integrated planning, and advanced monitoring tools for large-scale projects.
Paper: MOP7147
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP7147
About: Received: 12 May 2026 — Revised: 16 May 2026 — Accepted: 17 May 2026 — Issue date: 22 May 2026
MOP7148
Degassing of distilled water-cooling circuits and affected copper-walled structures
991
Cooling circuits that use distilled water to cool copper components such as magnets or cooling plates are susceptible to air leaks at fittings (for example, at the junction between plastic and metal tubing). The air that enters contains carbon dioxide, which lowers the pH from neutral 7 to acidic distilled water, allowing the accompanying oxygen molecules to react with the copper tubing surface, producing copper oxides. These copper oxides can accumulate and clog areas where the flow rate decreases (such as in flow reducers or collectors). This process thins the tubing walls and can eventually cause leaks. Frequent unclogging requires opening the circuit more often, which speeds up the damaging process. A very effective but costly solution is degassing each cooling circuit through reverse osmosis in a bypass setup.
Paper: MOP7148
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP7148
About: Received: 18 Apr 2026 — Revised: 16 May 2026 — Issue date: 22 May 2026
MOP7151
Challenges in the Development of the SIS100 Electrostatic Extraction System
998
The "Facility for Antiproton and Ion Research" (FAIR) is a new international accelerator complex, which is currently built in Darmstadt, Germany. Part of this complex is the SIS100 heavy ion synchrotron with a circumference of ~1086 m. One of the required extraction systems is the electrostatic septum. This septum was built by Danfysik. It is operating with voltages up to 180 kV. The requirements on the vacuum quality (low 10-11mbar region) combined with voluminous chambers (in total ~6m long), the reproducibility and precision of the applied voltage as well the mechanical stability and exact positioning even after bakeout cycles up to 300 °C have been the biggest challenges on this project. Specifications on rise and fall times for the high voltage implies the need of a bleeder resistor, used for improved voltage accuracy, too. During this project numerous problems had to been solved to end up with a stable system. The results of the tests and lessons learned will be presented.
Paper: MOP7151
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP7151
About: Received: 12 May 2026 — Revised: 14 May 2026 — Accepted: 19 May 2026 — Issue date: 22 May 2026
MOP7153
RF window Ti coating characterization
1005
Thin titanium coatings were deposited on alumina RF windows at CERN to reduce the secondary electron emission yield. The deposition process was optimized to ensure uniform coverage of the components used in high-power RF systems. Witness samples were characterized to assess their suitability for accelerator applications. Surface resistivity was measured under controlled conditions, while the Secondary Electron Yield was evaluated to determine the effectiveness of the coating in reducing electron emission. Thickness uniformity was characterized through detailed mapping using Rutherford Backscattering Spectrometry at the Laboratori Nazionali di Legnaro, providing spatially resolved information on deposition homogeneity and confirming process reproducibility. These results provide a comprehensive overview of the properties of the titanium coatings and serve as a useful reference for optimizing surface treatments of RF windows in accelerator facilities.
Paper: MOP7153
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP7153
About: Received: 13 May 2026 — Revised: 16 May 2026 — Accepted: 17 May 2026 — Issue date: 22 May 2026
MOP7158
Evaluation of low-cost, multimodal-sensor, data acquisition systems for ad-hoc applications in particle accelerators
1017
With more than 30km of beam lines and over 10,000 devices, CERN's particle accelerators are rich sources of data, providing real opportunities for developing new equipment monitoring and automation tools using data analysis and machine learning. The ready availability of low-cost computers and microcontrollers, such as Raspberry Pi and ESP32 devices, could enable a flexible data acquisition system for short-term applications that do not require, or cannot justify, the development and installation of permanent acquisition infrastructure. This paper presents the initial work from a pilot project to develop such a system, and assesses its use for several applications, including speculative investigations of environmental conditions, such as temperature and high-energy hadron flux, as well as assessing the feasibility of detecting arc faults in power converters, and gathering datasets for training machine learning models. Key considerations for the implementation of this system are also discussed, including concerns around network security, data quality, data availability, hardware configurations, deployment conditions, and avoiding control system dependency, with initial recommendations given for each.
Paper: MOP7158
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP7158
About: Received: 08 May 2026 — Revised: 16 May 2026 — Accepted: 17 May 2026 — Issue date: 22 May 2026
MOP7165
Results from the HEPTO combined function permanent magnet
1036
The Hybrid Electromagnet-Permanent Magnet Tuneable Optics magnet has been designed and built as part of the I.Fast collaboration as an energy saving alternative to traditional resistive electromagnets. The prototype magnet has been designed to meet the magnetic field requirements of the combined function dipole-quadrupole (DQ) magnets required for the Diamond-II upgrade. The prototype contains several design features for maintaining and tuning the field strength and quality, including a novel mechanical shimming method, trim coils and passive temperature compensation. We present here the results of the magnetic measurements of the built prototype magnet and demonstrate the ability to tune the field using the design features. We demonstrate that the nominal integrated field strength and homogeneity can be achieved with the permanent magnet solution, representing a 2.3 kW reduction in nominal power consumption compared to the equivalent electromagnet.
Paper: MOP7165
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP7165
About: Received: 06 May 2026 — Revised: 17 May 2026 — Accepted: 17 May 2026 — Issue date: 22 May 2026
MOP7166
Advances in magnetic field quality for ZEPTO tunable permanent magnet quadrupole
1040
The Zero Power Tuneable Optics (ZEPTO) project at STFC Daresbury Laboratory has developed several prototype permanent magnet quadrupoles (PMQs) with the largest tuning range so far demonstrated for any PMQ. By moving permanent magnet blocks relative to fixed steel structures that define the flux path,gradient is adjusted whilst homogeneity remains defined by the steel shape. Maintaining stable field homogeneity and magnetic axis position during adjustment remains a challenge that requires extremely high precision in manufacture and assembly to achieve. Based on lessons learned from the latest ZEPTO prototype, which ran for 2 years on Diamond Light Source, we have developed a fourth prototype which will be installed on the CLARA linear accelerator. This has 2 key developments over the previous prototype to overcome difficulties in manufacturing and assembly precision. If measurements show poor magnet harmonics or axis shift as a function of gradient, these are correctable in the new prototype without re-assembling the magnet or re-machining components. We show that by magnetic steel shims in defined patterns we can correct higher order field components, and that by removing rods of material from the yoke in pre-defined patterns we can tune or add field saturation in one half of the magnet to correct magnetic axis movement. This represents the next step into bringing this technology into direct competition with electromagnets in terms of convenience and reliability.
Paper: MOP7166
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP7166
About: Received: 07 May 2026 — Revised: 18 May 2026 — Accepted: 20 May 2026 — Issue date: 22 May 2026
MOP7167
Material-Extrusion additive manufacturing of pure copper components for accelerator vacuum systems
1044
This report presents a carried out study of the technology and performance of three-dimensional printing for the production of parts intended for ultra-high-vacuum assemblies. The simple part geometry was taken as the reference sample. Computer-aided design and finite element method (FEM) analysis are employed to predict thermomechanical stresses and deformations at the sintering stage. Experiments were conducted, and a comparative analysis was carried out to fit the initial FEM results with the experimental ones to obtain actual mathematical models for further simulations. During the printing process, the influence of layer thickness, nozzle temperature, and printing speed on the final density, dimensional accuracy, and surface quality is systematically investigated. Using the given essential parameters new printing setup was developed to ensure the highest density. New samples were printed with the different hole diameters to assess the actual properties using different accuracy printheads. The above-mentioned research was conducted to obtain the highest density of the printed parts, which will be used to evaluate the probability of the accelerator vacuum systems’ fabrication.
Paper: MOP7167
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP7167
About: Received: 31 Mar 2026 — Revised: 16 May 2026 — Accepted: 16 May 2026 — Issue date: 22 May 2026
MOP7169
Advancing ultra-high-frequency accelerators through metal additive manufacturing
1052
To reduce the footprint and construction costs of RF accelerators, there is a growing interest in operating at ultra‑high radio frequencies in the range of 0.3–3 GHz. At these frequencies, the longitudinal and transverse dimensions of accelerating structures shrink significantly, complicating the fabrication of intricate geometries and intensifying cooling challenges caused by high RF power densities. Metal additive manufacturing offers a promising solution by enabling the efficient realization of complex accelerator components while providing greater design flexibility to enhance overall performance. This paper focuses on the development of next-generation ultra-high-frequency accelerators and presents key results and highlights from ongoing metal additive manufacturing projects at GSI.
Paper: MOP7169
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP7169
About: Received: 12 May 2026 — Revised: 15 May 2026 — Accepted: 17 May 2026 — Issue date: 22 May 2026
MOP7170
Measurement of dielectric properties of 3D printed polymer-based materials for RF applications at 500 MHz
1056
To include 3D printed polymer-based materials in accelerator parts the relative permittivity and the dielectric loss tangent of these materials have to be well known. A quarter wave cavity was built to measure these properties at a resonance frequency of 500 MHz by inserting a cylinder of the material under test, resulting in a frequency and quality factor shift of the cavity. By fitting the measured data to detailed CST simulations, the values of the relative permittivity and the dielectric loss tangent can be obtained. These results provide the necessary material parameters for further investigations into their use in RF accelerator components such as power couplers.
Paper: MOP7170
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP7170
About: Received: 08 May 2026 — Revised: 18 May 2026 — Accepted: 20 May 2026 — Issue date: 22 May 2026
MOP7171
Experimental validation of an additively manufactured 1.3 GHz radio frequency cavity
1060
A compact continuous-wave (CW) 1.3GHz linear par ticle accelerator (linac) is currently under development as the core component of a high energy positron annihilation lifetime spectroscopy setup. The associated thermal load imposes stringent requirements on the design and manu facturing of the underlying multi-cell radio-frequency (RF) cavity. Metal-based laser powder bed fusion (PBF-LB/M) has recently demonstrated the capability to fabricate pure copperRFcavitiesasmonolithiccomponentswithintegrated complex geometries, such as cooling channels. In this work, we present and evaluate a first 1.3GHz single-cell RF cavity as a prototype for the intended multi-cell structure, manufac tured from pure copper using PBF-LB/M. Helium leak rate and low-level RF measurements meet the linac expectations. While the dimensional accuracy is reduced compared to con ventional manufacturing approaches, it can be compensated by an iterative design approach. These results demonstrate, for the first time, the feasibility of PBF-LB/M as a manufac turing route for monolithic 1.3GHz RF cavities.
Paper: MOP7171
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP7171
About: Received: 15 Apr 2026 — Revised: 18 May 2026 — Accepted: 22 May 2026 — Issue date: 22 May 2026
MOP7172
Post-processing of additively manufactured pure copper RFQ elements
1064
The utmost design freedom of additive manufacturing can be leveraged to fabricate complex particle accelerator components, such as the radiofrequency quadrupole (RFQ). However, the high surface roughness typical of as-printed parts represents a major barrier to the integration of additive manufacturing technologies into established fabrication workflows. This work investigates finishing processes aimed at improving the surface quality of additively manufactured RFQ components, with a focus on the hard-to-access vane tip region. A dedicated mock-up was developed, consisting of a copper vane representing a one-quarter RFQ section, mounted in a plastic holder to replicate the full part. This setup allows the copper part to be removed after each treatment step to measure material removal and assess effects on vane modulation, surface roughness, and overall geometric accuracy. Both mechanical mass finishing with abrasive media and chemical polishing were examined, applying each treatment in multiple intermediate steps. Comprehensive surface characterization was conducted after each finishing stage by means of profilometry, 2D and 3D roughness measurements, and 3D scanning to determine correlations between process parameters and resulting surface quality. The objective is to develop an optimed finishing strategy capable of achieving the surface quality and geometric accuracy required by RFQ and other advanced particle accelerator components.
Paper: MOP7172
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP7172
About: Received: 17 Apr 2026 — Revised: 14 May 2026 — Accepted: 17 May 2026 — Issue date: 22 May 2026
MOP7173
Optimized plasma electrolytic polishing for Cu 1.3 GHz SRF cavities
1068
The performance of Superconducting Radio Frequency (SRF) cavities is critically dependent on surface quality. While Electropolishing (EP) has traditionally been the standard for achieving low-roughness surfaces on Niobium (Nb) and Copper (Cu) substrates, it relies on hazardous and corrosive acids. Since 2019, Legnaro National Laboratories (LNL) has developed an eco-friendly alternative: Plasma Electrolytic Polishing (PEP). Utilizing only diluted salt solutions, PEP offers significant advantages over EP, including superior removal rates ($2\text{-}8~\mu\text{m/min}$ for Nb and $3\text{-}30~\mu\text{m/min}$ for Cu) and surface roughness ($R_a$) below tens of nanometers. Furthermore, the setup has been optimized to use external cathodes, eliminating the need for complex internal cathode insertion in elliptical cavities. Following the establishment of patented recipes in 2022, PEP was successfully applied to Cu $6~\text{GHz}$ elliptical cavities, QPRs, and 3D-printed devices. A major milestone was achieved in August 2024 with the successful scaling of the process to a $1.3~\text{GHz}$ Cu elliptical cavity. In collaboration with CERN and KEK, the RF performance of PEP was validated on a hydroformed seamless cavity (coated with Nb thin film), demonstrating compatibility and slight performance improvements over standard EP. Further RF validation of PEP on differently produced Cu 1.3 GHz cavities will be presented.
Paper: MOP7173
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP7173
About: Received: 13 May 2026 — Revised: 18 May 2026 — Issue date: 22 May 2026
MOP7176
Advancing accelerator components design through Additive Manufacturing
1075
Additive manufacturing (AM) enables new design approaches for accelerator components by allowing internal features, such as conformal cooling channels, to be integrated directly into parts. At the ISIS Neutron and Muon Source, development began with a polycarbonate cooling jacket for an RF plasma chamber, later replaced with glass-filled nylon due to sealing limitations. The work was extended to metal AM, including a stainless-steel beam dump produced by direct metal laser sintering (DMLS), demonstrating the need for selective post-machining of sealing surfaces. These lessons informed the design of an ion source main flange with internal cooling channels, successfully prototyped, machined, and validated using neutron imaging at the IMAT instrument. Current research focuses on ceramic AM for plasma chambers, integrating cooling channels within the ceramic wall to allow closer RF coil placement. A digital-light-processing (DLP) printed alumina green-body chamber has been produced as a proof of concept, supporting future development in aluminium nitride (AlN) and multi-material ceramic–copper systems for improved thermal management and performance improvements.
Paper: MOP7176
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP7176
About: Received: 13 May 2026 — Revised: 14 May 2026 — Accepted: 16 May 2026 — Issue date: 22 May 2026
MOP7178
A framework for environmentally conscious design of particle accelerators
1081
Particle accelerators typically use multiple times more electrical energy than the kinetic energy of the accelerated particles, resulting in low plug to beam efficiencies. The resources required for such machines are also substantial. Considering these points, we present a multifaceted approach with which we can calculate both the carbon emission impact for production and operation of particle accelerators, as well as the relative scarcities of materials used and their possible radioactivation during a lifecycle. To demonstrate a comprehensive use case, we apply these methods to the EcoCyclone permanent magnet cyclotron concept and compare to a normal-conducting coil powered cyclotron with the same output particle energy: the IBA Cyclone® Kiube. We find the two machines produce similar lifetime carbon emissions where the electricity supply is more carbonised, but caveats such as differing impacts of different material sourcing apply. We discuss how the calculated impacts may change over time, noting increasing electricity cost with decarbonisation, and argue these analyses should be performed during the design phase of all new accelerators.
Paper: MOP7178
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP7178
About: Received: 12 May 2026 — Revised: 15 May 2026 — Accepted: 15 May 2026 — Issue date: 22 May 2026
MOP7179
Preliminary power balance assessment of the PERLE Energy Recovery Linac
1085
The PERLE project aims to build a high power electron Energy Recovery Linac (ERL) demonstrator (5 MW) to develop and apply the energy recovery technique in a multi turn configuration. In an initial intermediate phase PERLE will operate in a single turn mode with a 5 mA beam at 89 MeV. In its final layout the machine will run in a three turn mode, delivering a 20 mA electron beam at 250 MeV. These challenging parameters make PERLE a unique multi turn ERL facility operating in an unexplored power regime, enabling the study and validation of a broad range of accelerator phenomena and paving the way for future, larger scale ERLs. The principal advantage of ERLs lies in their ability to return the power of a spent beam to the RF system. This recovered power can then be used for acceleration with practically no losses, thereby markedly improving the sustainability of high power machines. One of PERLE’s goals is to assess the overall sustainability of a multi megawatt ERL. In this work we present the current status of the studies carried out to evaluate the total electrical power consumption (“plug to grid”) of the accelerator for various operating modes—both single turn and multi turn—and relate this consumption to the average beam power delivered at the interaction point. We also discuss the power balance of a high power multi turn ERL and compare its efficiency with that of conventional accelerator types; e.g., linacs.
Paper: MOP7179
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP7179
About: Received: 13 May 2026 — Revised: 18 May 2026 — Accepted: 20 May 2026 — Issue date: 22 May 2026
MOP7180
Cooling-Tower technologies for the IFMIF-DONES heat rejection system: technical and environmental considerations
1089
The International Fusion Materials Irradiation Facility-DONES (IFMIF-DONES) is a scientific infrastructure intended to test and qualify materials for fusion reactors by exposing them to intense neutron fluxes. Several auxiliary systems will ensure its continuous operation, among which the Heat Rejection System (HRS) is designed to remove and discharge to the environment the heat mainly generated by the Accelerator's primary cooling loops and the Test Cell. While open evaporative cooling towers are widely used for industrial heat rejection, alternative technologies may be more suitable depending on site-specific conditions and project priorities. Environmental factors—particularly local weather patterns and their expected evolution under climate change—play a decisive role in overall system performance. Their proper assessment is therefore essential for selecting the most appropriate cooling-tower technology. This work presents a comparative evaluation of candidate heat-rejection solutions to identify the technology that best fits the site conditions, optimises performance over the system's life cycle, and supports the project's commitment to minimising its environmental footprint.
Paper: MOP7180
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP7180
About: Received: 13 May 2026 — Revised: 19 May 2026 — Accepted: 21 May 2026 — Issue date: 22 May 2026
MOP7182
Metal Additive Manufacturing for Accelerator Technologies (MAAT project at INFN)
1096
The MAAT (Metal Additive Manufacturing for Accel-erator Technologies) project is a three-year INFN re-search programme launched in 2026, aimed at establish-ing Additive Manufacturing (AM) as a validated produc-tion route for high-performance accelerator components. MAAT brings together three INFN units: Legnaro (LNL), Padova (PD), and Milano LASA, combining complemen-tary expertise in superconducting RF, materials science, and advanced manufacturing. This paper reports on the activities and preliminary results during the first year of the project, covering: 1. the Design for Additive Manufacturing (DfAM) of 6 GHz cavities produced by Laser Powder Bed Fusion (LPBF). 2. the preliminary tests of the Wire Laser Additive Manufacturing (WLAM) combined with CNC ma-chining for the fabrication of a 1.3 GHz RF cavity prototype in CuCrZr.
Paper: MOP7182
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP7182
About: Received: 13 May 2026 — Revised: 20 May 2026 — Issue date: 22 May 2026
MOP7183
Operational Sequencer at the European Spallation Source
1099
The Operational Sequencer is a software framework developed to automate complex and frequently executed high-level procedures that are essential to the operation of accelerator systems at the European Spallation Source (ESS). By transforming manual control room tasks into predefined sequences, the tool enhances process repeatability, reliability, and safety by reducing human error. Designed within the ESS Integrated Control System Software group, the sequencer provides a unified architecture for defining, executing, and monitoring operational tasks. It supports multiple task execution types, scalable system design, and an intuitive graphical interface to facilitate operator oversight. This paper presents the architectural concepts, implementation challenges, and scalability strategies of the Operational Sequencer, as well as lessons learned from its deployment during ESS commissioning. The framework represents a significant step toward efficient and reproducible operations, reducing both operator workload and time-to-beam for scientific experiments.
Paper: MOP7183
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP7183
About: Received: 12 May 2026 — Revised: 19 May 2026 — Issue date: 22 May 2026
MOP7185
Technological innovation for next-generation particle accelerators: key outcomes of the I.FAST project
1102
Next-generation particle accelerators demand innovative technologies able to meet the performance and sustainability requirements of particle physics and applied science, while ensuring high efficiency and reduced costs for industrial and societal applications. The I.FAST (Innovation Fostering in Accelerator Science and Technology) Project, supported by the European Commission under the Horizon2020 program, has fostered progress in the accelerator community by developing a portfolio of breakthrough technologies and strategic roadmaps for future research infrastructures, such as energy-frontier hadron and lepton colliders, and for medical and environmental applications. The project contributed to the development of novel accelerator designs – including multi-TeV muon colliders, plasma-based accelerators, and high-brightness synchrotron light sources – as well as advanced materials, high-performance components, and cutting-edge manufacturing and diagnostic tools. These efforts collectively aim to improve the energy-efficiency, sustainability, affordability, and compactness of future facilities. Key outcomes include novel radiation-resistant beam window and absorber materials, stabilization tools for laser accelerators, C- and X-band RF devices for free electron lasers, low-loss LTS and high-temperature superconducting CCT magnets, innovative SRF cavity fabrication and coating methods, additively manufactured linac structures, and high-efficiency klystrons and permanent magnets.
Paper: MOP7185
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP7185
About: Received: 16 May 2026 — Revised: 19 May 2026 — Issue date: 22 May 2026
MOP7186
CAD integration for the PETRA IV project
1106
The PETRA IV project at DESY in Hamburg aims for a new, 4th generation light source with first light in 2032. It comprises the installation of a completely new, 2.3km long 6GeV electron storage ring and a new injection chain, installation and refurbishment of 31 photon beam lines with 60 end stations, and the construction and refurbishment of 49 buildings including a new 600m long underground experimental hall. The project will reuse existing tunnels and halls of the PETRA III light source, and targets a dark time without beam of only 30 months, which is a challenging task that requires thorough planning. To meet this challenge, a comprehensive CAD model has been set up that integrates the data of all participants: construction, photon science, accelerator, campus and logistics. The model comprises representations of all systems and subsystems in different abstraction levels. A strict structure aligned with the project’s WBS and PBS, extensive use of interfaces, and a focus on review and change management processes ensure that the model is complete, consistent and correct and will remain so throughout the entire life cycle of the project.
Paper: MOP7186
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP7186
About: Received: 13 May 2026 — Revised: 21 May 2026 — Issue date: 22 May 2026
MOP7187
From lattice to engineering design: a rapid, reliable development cycle
1109
The future PETRA IV synchrotron radiation facility at DESY, Hamburg will be a 4th generation light source in the 2.3km long PETRA tunnel, with first light in 2032. It comprises 8 straight sections and 8 arcs with 288 girders and space for 72 insertions. The hybrid 6 bend achromat accelerator lattice aims for as much periodicity as possible to maximise symmetry, which is beneficial for beam dynamics, and minimise cell design variants. However, straight sections each fulfilling differing functions such as injection, rf acceleration or photon generation, more than a dozen variants of insertion devices, and differing tunnel cross sections introduce substantial variability of girders, cells, and arcs, increasing the engineering effort. We have set up an engineering process, supported by a set of automated tools, that establishes a rapid, reliable translation of the lattice to the positions of all components that act on the beam. More than 6000 individual beamline elements are positioned in this way.As part of the process, we analyse girder variants to minimise the number of different mechanical designs for magnets, vacuum, and other systems, and to facilitate logistics processes.A managed change process ensures that lattice updates are systematically propagated to the engineering design.
Paper: MOP7187
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP7187
About: Received: 13 May 2026 — Revised: 19 May 2026 — Issue date: 22 May 2026
MOP7191
Development of a Harmonised Framework for Electrical Safety Compliance at CERN
1115
Electrical safety has been identified as one of the main risks in large research infrastructures. At CERN, new regulations for electrical safety are being reviewed to align with current best practices and harmonise the approach. Among other aspects, it covers the compliance of electrical equipment and installations before they are put into operation, to further reduce the risk of accidents, to save time and cost by simplifying design processes, and to standardise the application of the legal requirements. While the new regulations were developed for CERN, they offer a model that can be applied to other research infrastructures. This paper describes the harmonised framework that was implemented to provide a practical guide for applying electrical compliance in the context of a research infrastructure. It was developed based on an analysis of best practices, validated through application to current CERN installations, and verified by industry experts. The framework optimises organisational efficiency by promoting ‘right-first-time’ compliance through a guided quality process. This work is part of the CERN Electrical Safety Project, an initiative established within CERN's Accelerator and Technologies sector to take proactive steps to further mitigate electrical risks, prevent recurrence, and build an even stronger safety culture.
Paper: MOP7191
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP7191
About: Received: 12 May 2026 — Revised: 15 May 2026 — Accepted: 17 May 2026 — Issue date: 22 May 2026
MOP7302
Mueller, Slater & Casimir versus & Kahan & Papas: time to set the record straight
1127
The relative fractional change of resonance frequency equals the fractional change in stored energy. This relation predicts the change of EM frequency when the walls of a metallic cavity are deformed or small objects inserted. J.M. Mueller derived this formula in 1939 by conceptual and mathematical errors. Casimir corrected those errors in 1949. The formula is also associated with J.C. Slater, published in 1946. Similar formulae were derived by Kahan in 1946 and by Papas in 1954. The Kahan version was reported, influentially, by Borgnis & Papas in the 1958 Handbook of Physics. Nevertheless, the relation is often called Slater's theorem. The Mueller, Slater and Casimir versions rely only on the properties of eigenfunctions, and electromagnetic boundary conditions at a metallic surface. The Kahan and Papas short cut to the formula relies on thermodynamics, the adiabatic theorem, perfect thermal isolation and infinite time, and that the cavity contains EM oscillations in quadrature. The latter derivation relies on assumptions that are artificial and unnecessary, and fails completely if there is no EM field present while the cavity is deformed. The situation of multiple derivations and attributions has led to some confusion. The time to set the record straight is overdue!
Paper: MOP7302
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP7302
About: Received: 10 May 2026 — Revised: 17 May 2026 — Accepted: 17 May 2026 — Issue date: 22 May 2026
MOP7602
Design of a C-band compact phase shifter for particle accelerators
1135
A phase shifter is a key component to tune the phase of RF power for accelerating or deflecting structures in linear accelerators (linacs). This paper presents the design of a compact C-band variable phase shifter for our high-power test platform. It consists of a dual-polarization mode coupler and a movable short-circuited piston for adjusting RF phases. In order to isolate the coaxial port formed by the movable piston and the pipe a choke is introduced inside the piston. Through optimizations, the RF phase variation is simulated to be 10.1233°/mm of piston moving distance.
Paper: MOP7602
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP7602
About: Received: 15 Apr 2026 — Revised: 17 May 2026 — Accepted: 20 May 2026 — Issue date: 22 May 2026
MOP8303
Standard and microbeam LINATRONs by Varex Imaging Corporation
1141
At Varex Imaging Corporation, High Energy Systems (HES) Department staff with help and support of our Production and Imaging groups continue adding new features to our LINATRON linear accelerator (LINAC) systems and transitioning new developments to our products. HES is at the final stages of productizing our usual LINATRONs, equipped with our new, in-house developed and built Accelerator Beam Centerlines (ABC). The products we offer today match or exceed the older products specifications, which were offered before we established our own ABC development and production line. In addition, we are making good progress on our new Microbeam LINATRON (MBL) systems, and we present the latest results on our MBL production prototypes. Our 6 MeV MBL6 prototype has been packaged, and it is under extensive testing and qualification process, getting ready for demonstration to our customers and for delivery. The similar packaging of our 3 MeV and 9 MeV LINATRON systems offers options of Ultra Low Leakage (ULL) shielding and of an integrated design packaging, now both for our security LINACs and for NDT LINACs under development.
Paper: MOP8303
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP8303
About: Received: 12 May 2026 — Revised: 17 May 2026 — Accepted: 18 May 2026 — Issue date: 22 May 2026
MOP8306
Conceptual design of a novel deuteron accelerator driven neutron source for nuclear waste transmutation
1147
A novel compact neutron source driven by *deuteron Cyclotron Auto-Resonance Accelerator* (dCARA) is under development to produce neutrons via breakup of high current 40-MeV deuterons on a low-Z target. Compared to the proton-based *Accelerator-Driven Systems* (ADS), a dCARA system can be much more compact and cost effective, with notable features including continuous acceleration without bunching for good beam stability, high efficiency, wide beam aperture, and an exceptionally short length of few meters. The applications of dCARA include transmutation of used nuclear fuel, medical isotope production system, or material test for a future fusion power reactor. The R&D progress and the conceptual design of dCARA are reported here.
Paper: MOP8306
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP8306
About: Received: 18 Apr 2026 — Revised: 16 May 2026 — Accepted: 17 May 2026 — Issue date: 22 May 2026
MOP8604
Proof-of-principle experimental design of solenoid-based relativistic electron beam pulse compression
1150
Relativistic electron beam pulse compression can enhance the beam current intensity within the pulse and generate higher peak current, showing significant potential for applications such as FLASH radiotherapy and wakefield acceleration. This paper proposes a proof-of-principle experimental design for a solenoid-based electron beam pulse compression scheme. The core device of the experiment, namely the magnetic compressor, has an approximately cylindrical structure with a diameter of 42 cm and a height of 47 cm. By utilizing the uniform magnetic field generated by the solenoids, the compressor converts the energy difference of the injected beam bunch into a path-length difference to achieve pulse compression. Simulation studies show that, under a transverse geometric emittance of $10~\mathrm{mm\cdot mrad}$, the beam loss remains below 10%, while the output current waveform exhibits a peak-to-peak ratio of approximately 5, demonstrating an obvious pulse compression effect.
Paper: MOP8604
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP8604
About: Received: 13 May 2026 — Revised: 17 May 2026 — Issue date: 22 May 2026
MOP8617
Accelerator-driven radiation studies of YSZ-MgO composites for nuclear applications
1156
YSZ and YSZ-MgO thin films were deposited on Si (100) substrates using RF sputtering and RF-DC co-sputtering techniques and studied under low-energy heavy-ion irradiation. Two sets of films were prepared: YSZ sputtered in argon environment and YSZ and Mg co-sputtered in argon and oxygen environment. Irradiation studies show enhanced crystallinity in single-component YSZ and significant degradation of YSZ crystallinity in YSZ-MgO films. These results indicate a strong dependence of radiation response on composition of the material.
Paper: MOP8617
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP8617
About: Received: 18 May 2026 — Revised: 20 May 2026 — Issue date: 22 May 2026
MOP8619
A report from ISBA25, accelerator school in Shanghai, China
1158
ISBA25 (The 8th International School on Beam dynamics and Accelerator technology) was held from September 1 to 10 in Shanghai, China. This is the 8th school of the ISBA series, which is a international accelerator school for graduate students and young researchers who are new to the accelerator field. The school curriculum is composed of fundamental topics (e.g., RF theory), applications (e.g., medical accelerators), and the latest topics (e.g,. AI in accelerators). More than 90 students from around the world participated and spent meaningful days, including Hands-on training for accelerator design, student presentations, a laboratory tour of SARI, and an excursion. The school is reported.
Paper: MOP8619
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP8619
About: Received: 16 Apr 2026 — Revised: 18 May 2026 — Accepted: 19 May 2026 — Issue date: 22 May 2026
MOP8620
IPAC’25 PRE session-report: fostering a productive research environment in the accelerator community
1161
The Productive Research Environment (PRE) session at IPAC’25 explored practices and challenges in fostering sustainable and motivating research environments in the accelerator community. A preliminary survey of 51 managers and leaders revealed high levels of motivation during the early career stage, but also highlighted concerns regarding staffing shortages, budgetary constraints, and the long-term career prospects of young researchers. Session presentations addressed career experiences, sustainable institutional models, and survey-based perspectives across different career stages. The subsequent panel discussion engaged additional senior leaders and covered key themes including human resources and diversity, leadership development, mentorship and supervision, and intergenerational collaboration. The session concluded that clear goals, adequate resources, inclusive cultures, structured leadership and mentoring, and effective knowledge transfer are essential for productive research environments. Despite current limitations, the strong motivation of young researchers offers a promising foundation. Building on this, PRE aims to expand its surveys and sustain dialogue at future IPAC meetings to strengthen human resource capacity and foster diversity across the global accelerator community.These findings and perspectives will be reported and further discussed at the conference.
Paper: MOP8620
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP8620
About: Received: 12 May 2026 — Revised: 17 May 2026 — Accepted: 17 May 2026 — Issue date: 22 May 2026
MOP8621
High-power test of a 40kW industrial electronic linear accelerator
1164
Electron accelerators with high average power output are widely used in radiation processing fields such as material modification, food sterilization, and environmental pollutant treatment. This paper presents a comprehensive high-power test of a 40kW electron accelerator. Key parameters including electron beam energy, average beam current, output power, and pulse characteristics were measured. The results show that the accelerator’s electron beam energy, the average beam current, and the effective output power all meet the design specifications. The energy test was performed via the aluminum foil stacking method, ensuring high measurement accuracy. This study validates the reliability and stability of the accelerator, providing technical support for its industrial application.
Paper: MOP8621
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOP8621
About: Received: 12 May 2026 — Revised: 16 May 2026 — Accepted: 20 May 2026 — Issue date: 22 May 2026
MOV7004
The potential of multi-material additive manufacturing illustrated by an RFQ prototype
1188
A variety of studies show that additive manufacturing (AM) of particle-accelerator components using laser powder bed fusion (PBF-LB/M) offers significant potential to reduce investment costs while simultaneously improving figures of merit. However, the classical PBF-LB/M process does not support combining different materials within a single piece. Conventional manufacturing routines are therefore still required, for example, to join steel flanges with knife-edge sealing interfaces to copper cavities. A novel multi-material (MM) PBF-LB/M process now enables the fabrication of high-quality (e.g., high-density) geometries by combining different materials such as Cu, CuCr1Zr, Ta, W, aluminum alloys, or stainless steel. Highly functional parts tailored to the diverse requirements of accelerator components can now be additively manufactured within a single process step. To demonstrate this potential for the first time, we fabricated a monolithic RFQ prototype from two different materials using MM PBF-LB/M. The RFQ’s inner cavity is manufactured from CuCr1Zr, enabling a complex, near-surface cooling system, while the co-printed outer shell is made of tool steel to integrate two CF63 and four CF16 flanges. The inner cavity surface was electropolished and subsequently copper plated to increase the quality factor. Low-level RF measurements match the performance predicted by CST simulations. The Helium leak rate is equivalent to those of conventionally manufactured RFQ cavities.
Paper: MOV7004
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-MOV7004
About: Received: 08 May 2026 — Revised: 20 May 2026 — Accepted: 22 May 2026 — Issue date: 22 May 2026
TUO8T01
First mixed He/C ion beams at a clinical facility: two years from concept to first ion imaging experiments
1213
Patient irradiation with mixed 4He2+ and 12C6+ ion beams is a promising proposal for online monitoring in carbon ion therapy. Over the past years, major developments have enabled the generation of such beams at MedAustron, where they are now used in accelerator, detector, and medical physics research projects. This contribution summarizes the key innovations that made this achievement possible. Among these are a new double multiturn injection scheme for merging helium and carbon ion beams in the synchrotron, concepts for simultaneous slow extraction of both ion species, and dedicated diagnostic tools for mixed beam characterization in the accelerator and experimental room. Together, these advances pave the way for continued progress in the field of mixed ion beam acceleration and application.
Paper: TUO8T01
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-TUO8T01
About: Received: 13 May 2026 — Revised: 16 May 2026 — Accepted: 17 May 2026 — Issue date: 22 May 2026
TUO8T02
Accelerators activities at ENEA for aerospace
1217
The ENEA Frascati Particle Accelerator Laboratory operates a set of S-band electron and proton linear accelerators providing beams relevant for radiation-effects studies in the aerospace sector. The TOP-IMPLART proton LINAC delivers low-energy (1–6 MeV) and high-energy (up to 71 MeV) beams, while the REX and TECHEA facilities supply 3.5–5 MeV and 1–3 MeV electron beams, respectively; both can also operate as X-ray sources via removable bremsstrahlung converters. The contribution reviews ENEA activities in aerospace applications, including irradiation of electronic components, material and shielding studies, and radiobiology and astrobiology experiments. ENEA is involved in several national and European projects— such as Cyptomars, Space It Up!, Space-EBC, and Thread — addressing key topics for space exploration. In parallel, ENEA provides irradiation services within infrastructures such as DIANA and ASIF supporting component testing and material qualification. This work highlights ENEA’s role in supporting the aerospace community through advanced accelerator capabilities, coordinated research initiatives, and a broad portfolio of irradiation services aimed at enhancing the robustness and space-readiness of technologies for future missions.
Paper: TUO8T02
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-TUO8T02
About: Received: 11 May 2026 — Revised: 20 May 2026 — Accepted: 20 May 2026 — Issue date: 22 May 2026
TUV8002
Mapping Global Collaboration in Accelerator Research
1222
This contribution examines particle accelerator research through a sociological lens. It combines a database of accelerator counts per country with a large corpus of accelerator-related publications from Web of Science to analyse how infrastructure distribution shapes scientific collaboration across regions and disciplines. The results reveal marked geographical asymmetries: some regions sustain dense internal publication networks while others participate primarily through cross-regional partnerships. The analysis also identifies clear disciplinary differences in how fields such as astronomy, materials science, and chemistry mobilise accelerator infrastructure through distinct collaboration configurations. Together, these patterns illustrate how scientific collaboration crystallises around shared infrastructures, how expertise circulates unevenly between regions, and how accelerators support the emergence of differentiated epistemic communities. The study offers an empirical perspective on the social dynamics underpinning global accelerator research and raises questions for future qualitative and longitudinal investigation.
Paper: TUV8002
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-TUV8002
About: Received: 13 May 2026 — Revised: 18 May 2026 — Issue date: 22 May 2026
TUI3T01
High quality electron beams with tunable energy produced by laser-plasma acceleration
1228
Laser wakefield acceleration (LWFA) of electrons occurs when an intense short laser pulse focused in an underdense plasma drives in its wake a plasma wave with an amplitude large enough to trap and accelerate electrons. Relativistic electron bunches are easily obtained through this mechanism and have given rise to a large number of studies and publications. Despite these efforts, the achievement of a high quality reliable electron source, ready for use in applications, still needs some developments. Electron beams with high quality, and tunable electron energy, have been achieved by the authors using the DRACO facility (HZDR Dresden), showing that the injection and acceleration processes can be controlled consistently in a gas cell. Dark current free, relativistic electron bunches with energy peaked at tunable values between 60 MeV, and 200 MeV, 40 pC charge in the peak and sub-mrad rms divergence, reaching up to 14pC/MeV/mrad, have been achieved experimentally and reproduced in PIC simulations using measured input parameters. On going work is aimed at increasing the charge in the peak beyond 100pC through new gas cell development.
Paper: TUI3T01
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-TUI3T01
About: Received: 12 May 2026 — Revised: 19 May 2026 — Accepted: 22 May 2026 — Issue date: 22 May 2026
TUI3T02
First direct observation of a wakefield generated with structured light
1233
Since their inception, laser-wakefield accelerators (LWFAs) have shown their capability to produce high-quality, monoenergetic electron beams. Yet, the push toward higher electron energies and more efficient accelerators is constrained by several limitations. Foremost among these are the dephasing and diffraction limits. A promising strategy to address these issues involves using structured light to modulate the on-axis propagation velocity in LWFAs. By pairing the diffraction-resistant properties of Bessel beams with spatio-temporal pulse shaping, this approach offers an unprecedented combination of extended acceleration lengths and strong acceleration gradients. Here we present the first experimental observation of wakefields driven by such structured beams. Spatio-temporally tailored pulses are directed through a specialized focusing mirror to form a quasi-Bessel beam, and the resulting wakefield is directly probed using femtosecond relativistic electron microscopy. Simulations corroborate the experimental data, offering novel insights into this underexplored regime. We show an experimental demonstration of the ability to modify the on-axis propagation velocity of the wakefield. We track the wakefield’s evolution throughout the focal region and examine how specific spatio-temporal manipulations influence both its structure and propagation velocity. Finally, we present the first results using such wakefields to accelerate electrons. These findings establish a foundation for harnessing structured-light-based strategies to overcome dephasing in LWFA. [1] A. Liberman et al., “Direct Observation of a Wakefield Generated with Structured Light,” Nature Communications, Accepted. (https://arxiv.org/abs/2503.01516) [2] A. Liberman et al., “First Electron Acceleration in a Tunable-Velocity Laser Wakefield,” under review. (https://arxiv.org/abs/2509.21098) [3] A. Liberman et al., “Probing Flying-Focus Wakefields,” under review. (https://arxiv.org/abs/2510.16950) [4] A. Liberman et al., "Use of spatiotemporal couplings and an axiparabola to control the velocity of peak intensity," Opt. Lett. 49, 814-817 (2024)
Paper: TUI3T02
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-TUI3T02
About: Received: 10 Apr 2026 — Revised: 16 May 2026 — Accepted: 17 May 2026 — Issue date: 22 May 2026
TUI4M02
Accelerator complex evolution at Fermilab
1244
The largest hadron accelerator facility in the US is undergoing radical changes and the undertaking of new HEP-driven neutrino research. This talk will discuss the wide-ranging projects and impacts to the accelerator community taking place at FNAL.
Paper: TUI4M02
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-TUI4M02
About: Received: 12 May 2026 — Revised: 19 May 2026 — Accepted: 20 May 2026 — Issue date: 22 May 2026
TUO2M05
CLARA commissioning and first friendly user experiments
1253
The CLARA facility at Daresbury Laboratory is a medium energy user facility for wide range of applications such as novel acceleration, cancer-therapy, and advanced diagnostics research. CLARA is currently finalising beam commissioning after an extended period of technical systems commissioning. During this period CLARA hosted its first set of “friendly” user experiments in its dedicated shielded user beamline, FEBE. Five different experiments were selected for the first user run, covering a range of applications including: advanced diagnostics measurements using coherent transition radiation (CTR) and optical transition radiation (OTR) stations; Very High Energy Electron (VHEE) cancer-therapy studies; beam-driven plasma wakefield acceleration studies related to next generation colliders. These experiments were conducted exploiting the full capabilities of the CLARA facility, including up to 250 MeV/c bunches with up to 250 pC per bunch at 100 Hz repetition rate, and with variable longitudinal compression regimes. The experiments chosen will also develop and prepare CLARA for the transition to a full user facility. Further user experiments are expected to be performed later in 2026, after final commissioning of the 120 TW laser system in FEBE, which will expand the range of experiments to include those combining electron beams and high-power lasers.
Paper: TUO2M05
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-TUO2M05
About: Received: 11 May 2026 — Revised: 17 May 2026 — Accepted: 22 May 2026 — Issue date: 22 May 2026
TUP2306
CLS: return to operation
1292
In 2024, the CLS linac injector was removed and exchanged with a newer more compact injector capable of 10 Hz operation and producing an electron beam of 250 MeV. Unfortunately the commissioning did not go as planned and the facility stayed dark 1 year longer than planned. We are summarizing what it took to provide beam to our users and the plan to remediate to the existing deficiencies and the risk associated to them.
Paper: TUP2306
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-TUP2306
About: Received: 23 Apr 2026 — Revised: 17 May 2026 — Accepted: 19 May 2026 — Issue date: 22 May 2026
TUP2316
Machine Learning based preventive maintenance and autonomous power control for RF cavities in a free-electron laser
1299
This project develops a machine learning–based system to prevent RF cavity trips in the free-electron laser by autonomously controlling the applied RF power. Sudden vacuum and current fluctuations within the cavities can cause reflections that trip the machine, and continuous manual monitoring throughout the conditioning process isn't feasible. To address this and potentially improve the conditioning efficiency, process-variable data was collected and analyzed to identify patterns in cavity behavior across operating power levels. A hybrid model combining clustering methods, linear regression, and a classifiers was designed to categorize current ranges, estimate baseline behavior, and detect anomalies. The resulting control program evaluates the machine state over short intervals, decreases power during unsafe conditions, increases it during prolonged stability, and can automatically reset the RF system after a trip. This approach enables faster and safer conditioning of the RF cavities, reduces operator workload, and provides a pathway toward fully autonomous preventive maintenance.
Paper: TUP2316
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-TUP2316
About: Received: 01 Apr 2026 — Revised: 17 May 2026 — Accepted: 17 May 2026 — Issue date: 22 May 2026
TUP2332
RF kicks in the Super Conducting Linac of LCLS-II
1314
RF kicks are produced by misalignments between an electron beam in the acceleration structure. By analyzing these kicks, produced by the super conducting standing wave accelerator for the Linac Coherent Light Source (LCLS-II), a few unexpected observations were recognized. Initially an out-off-phase (90 deg off the accelerating phase) component was observed, which is similar in size to the expected by theory in-phase component. Then other observations like modeling errors (e.g.: not closed three-corrector bumps) let to a deeper analysis of the currently used model.
Paper: TUP2332
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-TUP2332
About: Received: 13 May 2026 — Revised: 21 May 2026 — Accepted: 21 May 2026 — Issue date: 22 May 2026
TUP2333
Dual beam dynamic modes in a Compact Standing Wave Linear Accelerator
1317
Tong Chen* (RefleXIon Medical Inc.) Hao Tao, Liang Huo, Tong Li, Zhen Feng, Lin Zhou, Yongtao Liu* (Chengdu Elekom Vacuum Electron Technology Co. Ltd) It has been commonly observed that the beam spot profile of compact standing wave linacs have a dual Gaussian distribution. Further study of this paper shows that the two Gaussian distribution is generated by different acceleration process and beam dynamics. Simulation data analysis concludes that the particles in the two Gaussian distributions are strongly dependent on their initial phases. Experiment results have demonstrated the two Gaussian distributions responded differently to steering magnetic field.
Paper: TUP2333
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-TUP2333
About: Received: 30 Mar 2026 — Revised: 16 May 2026 — Accepted: 16 May 2026 — Issue date: 22 May 2026
TUP2345
Consideration of an unbunched high energy electron storage ring
1348
Electron storage ring light sources rely exclusively on RF cavities to restore energy to the beam that is lost to photon emission. A limitation of RF is that it can store particles in only a small region of the RF waveform, yielding a bunched beam. Only a few percent of the ring circumference actually contains charge. Thus, high average current entails high peak current. While high average current and low emittance are the target parameters of the light source, the limitations come from peak current effects. With recent advances, induction cells are potential replacements for RF cavities. The cells are compact, and a small number of them could be orchestrated to provide DC, or nearly DC, restoring voltage, yielding a continuous, unbunched beam. SLAC is investigating the physics of continuous beam induction storage rings. Potential applications include continuous beam light sources with smaller emittances and higher currents, and also coherent emission light sources utilizing steady state microbunching (SSMB). For applications including SSMB, we are also investigating isochronous rings based on anti-bend cell acromats.
Paper: TUP2345
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-TUP2345
About: Received: 14 May 2026 — Revised: 19 May 2026 — Accepted: 21 May 2026 — Issue date: 22 May 2026
TUP2602
Progress of physics studies and beam commissioning of the High Energy Photon Source
1367
The High Energy Photon Source (HEPS) is a 35-pm, 1360-m storage ring light source being built in the suburb of Beijing, China. The HEPS construction started in 2019, with the main civil construction finished at the end of 2021. In the past two years, the beam commissioning of the HEPS storage ring had been started and bascially finished. In this paper, we will briefly introduce commissioning of the HEPS storage ring, and relavent physics studies.
Paper: TUP2602
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-TUP2602
About: Received: 11 May 2026 — Revised: 18 May 2026 — Accepted: 20 May 2026 — Issue date: 22 May 2026
TUP2607
Beam based alignment of quadrupoles at HEPS
1375
In modern storage ring light source, large offset of quadrupoles will degrade the beam quality in the ring. Beam based alignment(BBA) methods have been used widely in storage rings, to correct the orbit of the beam to the magnetic center of quadrupoles. The BBA algorithm and commissioning procedure at HEPS is described in this paper
Paper: TUP2607
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-TUP2607
About: Received: 13 May 2026 — Revised: 16 May 2026 — Accepted: 18 May 2026 — Issue date: 22 May 2026
TUP2614
Performance comparison between variable bending magnets and Sandwich magnets in the Southern Advanced Photon Source
1385
The Southern Advanced Photon Source (SAPS) is a planned 3.5 GeV ultra-low emittance storage ring based on a modified hybrid 7-bend achromat (H-7BA) lattice, located in Dongguan, China. To achieve an extremely low natural emittance, the lattice incorporates a novel unit cell consisting of a 'Sandwich' bending magnet combined with reverse bends. This design has resulted in a remarkable natural emittance of 26.3 pm·rad. Although variable bending magnets with a trapezoidal bending radius and gradient are also recognized for their effectiveness in emittance reduction, their performance relative to the compact thin-center 'Sandwich' design remains unclear. This paper presents a comprehensive comparison of these two magnet configurations, detailing the nonlinear optimization process and evaluating their respective performance.
Paper: TUP2614
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-TUP2614
About: Received: 13 May 2026 — Revised: 18 May 2026 — Accepted: 20 May 2026 — Issue date: 22 May 2026
TUP2616
Optimization of the response matrix measurement application in Pyapas
1389
Measurement of the response matrix serves as the foundation for orbit correction and OPICTS correction. To obtain more accurate response matrix data while minimizing the measurement time, we have meticulously optimized parameters such as the number of data points collected by Beam Position Monitors (BPMs) and the waiting time. Additionally, due to the long overall measurement duration for the entire ring, factors including orbit drift and hysteresis effects during the process can introduce deviations to the measurement results. Therefore, we integrated response matrix measurement with orbit correction and radio frequency (RF) frequency adjustment to further ensure the consistency of the beam state throughout the entire measurement process. This paper will elaborate on the relevant work in detail
Paper: TUP2616
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-TUP2616
About: Received: 13 May 2026 — Revised: 19 May 2026 — Accepted: 21 May 2026 — Issue date: 22 May 2026
TUP2629
Generation and diagnostics of nanosecond-interval laser pulse trains with femtosecond-level timing control for the Korea-4GSR photocathode RF gun
1413
The Korea-4GSR (4th Generation Storage Ring) requires a highly stable and precisely synchronized laser pulse train to drive its photocathode RF gun in multi-bunch mode. To meet this requirement, we developed a laser system capable of generating nanosecond-interval pulse trains with femtosecond-level timing control. The pulse train is formed using a beam-split/delay-and-combine method, producing a 64-pulse sequence with 2 ns separation, synchronized to a 500 MHz RF reference. To further enhance synchronization accuracy and diagnose timing jitter at the femtosecond scale, a 500 MHz femtosecond oscillator is being developed and integrated into the system. This fs-oscillator enables precise timing diagnostics, long-term drift monitoring, and improved stability for multi-bunch operation. The combined system is designed to provide low-emittance, low-energy-spread electron bunches required for Korea-4GSR’s high-brightness injector and ensures reliable operation in both single-shot and multi-bunch modes.
Paper: TUP2629
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-TUP2629
About: Received: 04 May 2026 — Revised: 20 May 2026 — Accepted: 20 May 2026 — Issue date: 22 May 2026
TUP2661
Design study of injector system using rf electron gun with gridded thermionic cathode towards soft X-ray free-electron laser
1452
The high-brightness synchrotron radiation facility “NanoTerasu” provides users with extremely stable synchrotron radiation by top-up injecting an electron beam from a 3-GeV linear accelerator into a diffraction-limited storage ring. NanoTerasu plans to develop a soft X-ray free-electron laser (SX-FEL) using the linear accelerator. To realize SX-FEL with practical gain length, it is required that the linear accelerator generates an electron beam with a peak current of 2 kA and a normalized emittance of 2 mm mrad or less. We have already developed a low-emittance electron gun system with a gridded thermionic cathode and have begun designing a low-emittance injector system using the electron gun system. The linear accelerator based on the electron gun system is planned to serve as both the storage ring’s injector and SX-FEL’s driver. This presentation describes the configuration of a compact SX-FEL linear accelerator that can be installed within existing facilities. It also presents a bunch compression scheme while maintaining slice emittance, along with particle tracking simulation results of the new injector system.
Paper: TUP2661
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-TUP2661
About: Received: 11 May 2026 — Revised: 20 May 2026 — Accepted: 22 May 2026 — Issue date: 22 May 2026
TUP2664
Optimization of a storage ring pre-injector for high transmission efficiency and low energy spread
1456
In this paper, the Non-dominated Sorting Genetic Algorithm II (NSGA-II), combined with the beam dynamics code ASTRA, was employed for the multi-objective optimization of the output performance of an electron linear accelerator (linac). Taking the pre-injector of a storage ring light source as an example, the electron linac consists of a thermionic cathode high-voltage electron gun, a sub-harmonic buncher (SHB), a buncher, and a traveling-wave accelerator tube. Maximizing the transmission efficiency and minimizing the energy spread were defined as the core objectives of the optimization. The optimization results indicate that the beam energy at the linac exit reaches approximately 65 MeV, with the transmission efficiency exceeding 70% and the energy spread maintained below 0.35%.
Paper: TUP2664
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-TUP2664
About: Received: 15 Apr 2026 — Revised: 18 May 2026 — Accepted: 22 May 2026 — Issue date: 22 May 2026
TUP2665
Beam dynamics analysis of an electron microtron using General Particle Tracer
1460
Electron microtrons are extensively employed as injectors for tabletop light source facilities. In this paper, a 5 MeV electron micrtron is designed, and an external injection scheme is adopted to achieve a large stable longitudinal phase region. We investigated the beam dynamics of this microtron using General Particle Tracer (GPT). After optimization, the width of stable longitudinal phase region is approximately 40°, which is about four times larger than that of conventional internal-injection microtrons.
Paper: TUP2665
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-TUP2665
About: Received: 25 Mar 2026 — Revised: 15 May 2026 — Accepted: 16 May 2026 — Issue date: 22 May 2026
TUP2670
The collimator system for reducing the dark current in NSRRC photoinjector
1469
The NSRRC photoinjector generates ultrashort electron beams for the production of superradiant radiation in the 100–500 μm wavelength range using a gap tunable U100 planar undulator. The accelerator consists of an S band, laser driven photocathode RF gun equipped with a compensation solenoid, followed by a 5 m long linear accelerator. Sub picosecond electron bunches are achieved through velocity bunching in the linac. Under specific operating conditions, electrons emitted from the cathode surface may be accelerated to high energies independently of the main beam, which continues to gain energy in the linac. These stray electrons can impact the vacuum chamber, producing unwanted radiation that poses risks to both accelerator components and radiation safety. To suppress dark current, a collimator was installed between the photocathode gun and the linac to intercept these electrons prior to downstream transport. Experimental measurements and numerical simulations are presented, demonstrating the effectiveness of the collimator system in reducing dark current.
Paper: TUP2670
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-TUP2670
About: Received: 11 May 2026 — Revised: 18 May 2026 — Accepted: 21 May 2026 — Issue date: 22 May 2026
TUP2678
Analysis and compensation of the insertion device effects in the HALF storage ring
1484
The Hefei Advanced Light Facility (HALF) is a diffraction-limited storage ring light source with a beam energy of 2.2 GeV. There are 13 insertion devices (IDs) will be installed in the storage ring, which will have severe impacts on the low-energy beam. Especially for the long-period EPU, the non-linear effect will significantly reduce the dynamic aperture of the storage ring. In this paper, the IDs effects are analyzed in detail with kick-map models for the HALF storage ring. Each ID is compensated using a local quadrupole feedforward method. For some EPUs with significant impacts, additional compensation is provided through the shimming of current strips. The analysis and compensation results will be presented in this paper.
Paper: TUP2678
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-TUP2678
About: Received: 15 Apr 2026 — Revised: 18 May 2026 — Accepted: 18 May 2026 — Issue date: 22 May 2026
TUP2680
Investigation of the compensation scheme using the broadband kicker cavity to mitigate the transient beam-loading effect in synchrotron light sources
1492
Bunch lengthening technique is most reliable method to mitigate the intrabeam scattering in synchrotron light sources. The performance of the bunch lengthening can be degraded by a transient beam-loading (TBL) effect, which becomes large when long gaps are introduced in the bunch filling pattern. To mitigate the TBL effect, we have proposed a compensation method using a broadband cavity [1]. We have investigated the conceptual design of the kicker cavity and carried out the performance tests of the low-power model cavity that can be used to compensate for the TBL effect [2]. In this presentation, details and further discussions about the performance of the TBL compensation will be reported based on the results of the performance tests and semianalytical calculation. As an example, the TBL compensation at the KEK PF 2.5 GeV ring is investigated using semianalytical calculations. The strategy of the TBL compensation at the PF ring is discussed. The performance of the TBL compensation using the kicker cavity is investigated. [1] N. Yamamoto et al, Phys. Rev. Accel. Beams 21, 012001 (2018) [2] D. Naito et al, Phys. Rev. Accel. Beams 28, 112002 (2025)
Paper: TUP2680
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-TUP2680
About: Received: 15 Apr 2026 — Revised: 15 May 2026 — Accepted: 17 May 2026 — Issue date: 22 May 2026
TUP2695
Commissioning of the injector system for the X-band electron linear accelerator in Melbourne
1516
The University of Melbourne’s X-band Laboratory for Accelerators and Beams (X-LAB) is developing a compact electron linear accelerator. The injector system will consist of a 100 keV DC photogun, a pulsed UV laser, an S-band (2.9985 GHz) RF buncher, and magnetic elements for beam transport. This paper reports on the commissioning of the injector system. We present the characterisation of the test laser and buncher, as well as initial electron beam measurements with Faraday cup. Particle tracking simulations using General Particle Tracer (GPT) code were used to obtain approximate optimal solenoid currents. We also report on the conditioning of the photogun, including photocathode inspection, vacuum performance, dark current, and stray radiation.
Paper: TUP2695
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-TUP2695
About: Received: 12 May 2026 — Revised: 21 May 2026 — Accepted: 21 May 2026 — Issue date: 22 May 2026
TUP2697
Analysis of beam loading effect of dark current in C-band photocathode electron gun
1520
In the research on high-gradient photocathode electron guns, the existence of dark current not only affects the measurement of photo-beam but also causes problems such as secondary electron multiplication and an increased difficult of condition. In this paper, the sources of dark current emission inside the electron gun and their impact duiring the power test are discussed through simulations. Additionally, combined with the test results from the C-band electron gun test platform in the pre-research project of the Southern Advanced Photon Source, the beam loading effect introduced by dark current is analyzed. The results show that when the dark current in the test is > 10 mA, it will increase the coupling parameters of the cavity and reduce the cathode accelerating field gradient.
Paper: TUP2697
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-TUP2697
About: Received: 13 May 2026 — Revised: 18 May 2026 — Accepted: 19 May 2026 — Issue date: 22 May 2026
TUP2714
GPU-Accelerated simulation framework for partially coherent EUV light transport in Tsinghua SSMB beamline optics
1546
Accurate simulation of partially coherent beam transport and coherence evolution is critical for next-generation accelerator-based light sources. In this work, we develop a dedicated numerical approach for partially coherent EUV beamline propagation to support the optical design and optimization of Steady-State Microbunching (SSMB) beamlines under development at Tsinghua University.* A GPU-accelerated mutual optical intensity framework is developed for two-dimensional propagation of partially coherent radiation. Using spatially partitioned diffraction-integral kernels with locally reconstructed paraxial approximation, the method achieves substantial speedup over conventional mutual-intensity and wavefront-based propagation methods while maintaining high accuracy. Complex optical components, including arbitrary curved and rough reflective surfaces, are fully supported for efficient simulation of realistic EUV systems. In summary, the proposed framework provides a practical tool for optical design and end-to-end simulation of EUV beamlines, enabling coherence analysis and accurate light propagation modeling of partially coherent radiation.
Paper: TUP2714
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-TUP2714
About: Received: 19 Mar 2026 — Revised: 16 May 2026 — Accepted: 17 May 2026 — Issue date: 22 May 2026
TUP3001
Analytical solenoid matching routines with coolpy
1554
Muon colliders require strong beam cooling to reduce the large phase space of muon beams produced from pion decay. The final stage of ionization cooling employs high-field solenoids, absorbers, and RF cavities, where precise beam matching is essential to avoid emittance growth. In this work, we present a beam-parameter–based approach to design and optimize solenoid lattices for the final cooling channel. The method models realistic solenoid fields and solves the coupled beam envelope equation while accounting for momentum changes in absorbers and RF systems. To implement this approach efficiently, we developed the Python package coolpy, which computes the evolution of Twiss parameters and optimizes matching coil settings. Two case studies demonstrate matched beam transport in solenoid-based beamlines.
Paper: TUP3001
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-TUP3001
About: Received: 10 May 2026 — Revised: 19 May 2026 — Accepted: 21 May 2026 — Issue date: 22 May 2026
TUP3008
Research status on the ECRIPAC accelerator concept
1558
This study presents the current advancement on our investigation of the Electron Cyclotron Resonance Ion Plasma Accelerator (ECRIPAC), revisiting and greatly expanding this original accelerator concept initially developed in the nineties\*. ECRIPAC is an innovative compact plasma device able to generate energetic pulsed ion beams using robust and well mastered electron cyclotron resonance ion source technologies, without requirements for axial RF cavities or powerful laser beams. It relies on the gyromagnetic auto-resonance of plasma electrons in a time growing magnetic field\*\*, followed by the axial acceleration of ions through the plasma space-charge field inside a magnetic field gradient, up to energies close to 100 MeV/A. The theoretical behaviour of ECRIPAC is summarized. Some preliminary results of kinetic plasma simulations inside a preliminary design of an ECRIPAC machine able to accelerate He2+ ions up to approximately 10 MeV/A are presented. Two sets of simulations are considered, one working with a cylindrical geometry and azimuthal mode decomposition in the open-source code Smilei\*\*\* and the other using a 3D geometry in the open-source code WarpX\*\*\*\*, providing interesting insights on the plasma behaviour inside the accelerator.
Paper: TUP3008
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-TUP3008
About: Received: 12 May 2026 — Revised: 20 May 2026 — Accepted: 21 May 2026 — Issue date: 22 May 2026
TUP3009
Beamline optimization for Laser-Accelerated Ions
1562
Laser-plasma acceleration can generate short, intense ion beams with energies up to several hundred MeV. However, the intrinsic large divergence and broad energy spectrum of these beams necessitate dedicated capture and transport beamlines to achieve high particle yields for applications. In this work, we use the LIGHT beamline with the PHELIX laser at GSI as an example case to develop and evaluate methods for optimizing and aligning such beamlines. Our focus is on future applications including injection into conventional accelerators and as a complement to traditional ion sources. Using the UNILAC at GSI as a reference case, we show that, for the present PHELIX laser intensities the number of laser-accelerated protons viable for SIS18 injection remains at least an order of magnitude below the typical bunch intensity of conventional linacs. Finally, by deriving and applying scaling laws for the transmission through the first capture element, we propose strategies for further improvement to bridge this gap in the future.
Paper: TUP3009
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-TUP3009
About: Received: 13 May 2026 — Revised: 18 May 2026 — Accepted: 21 May 2026 — Issue date: 22 May 2026
TUP3010
SMART - a SMall pArticle accelerRaTor on chip
1565
The miniaturization of particle accelerators via Dielec tric Laser Acceleration (DLA) * offers a route to ultra compact, cost-effective devices poweredbycommerciallaser systems. This work explores the extension of DLA technol ogy—historically focused on electrons—to protons, aiming to enable "on-chip" sources of high energy hadrons. We present the design and simulation of a novel microstruc ture optimized for the acceleration of non-relativistic pro tons. Key challenges addressed include the management of phase slippage and the requirement for strong transverse confinement of heavy particles at low 𝛽. This study aims to demonstrate the potential for stable acceleration and fo cusing, validating the pDLA(proton-DLA) ** concept as a viable candidate for future compact accelerator architectures.
Paper: TUP3010
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-TUP3010
About: Received: 24 Apr 2026 — Revised: 17 May 2026 — Accepted: 20 May 2026 — Issue date: 22 May 2026
TUP3014
Interaction of high-intensity beam with structured solid surface plasma for wakefield acceleration and coherent radiation generation
1568
Recent research into the interaction between high-intensity beams and surface plasmas has revealed the significant potential of generating extremely strong (~TV/m) fields for particle acceleration and radiation production. This new approach has emerged by overcoming several challenges in beam-solid interactions. It therefore holds great promise for reshaping the research direction of large-scale facilities pursuing the energy frontier and micro-scale facilities requiring great flexibility. At the same time, this research can provide new insights into the extremely complex nonlinear dynamics of surface plasmons (SPs) in strong fields and a new, unexplored regime of plasma-based particle acceleration. In this study, we theoretically investigate the high-intensity laser- or beam-driven excitation of relativistic surface plasmons on the micro-scaled surfaces of structured nanomaterials, such as vertically aligned carbon nanotube (VACNT) forests. Leaky and bubble wakefields can be generated with amplitudes exceeding 400 TV/m and high energy efficiency for both electron and positron acceleration. By investigating SP mode selection on cylindrical surfaces, we have proposed a new principle for coherent radiation generation that differs fundamentally from traditional superradiance. Our research offers a new approach to the development of ultrahigh-gradient and ultra-compact particle accelerators, which could transform medicine and materials science.
Paper: TUP3014
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-TUP3014
About: Received: 11 May 2026 — Revised: 22 May 2026 — Issue date: 22 May 2026
TUP3016
cSTART – Status on the compact electron STorage ring for non-equilibrium Accelerator Research and Technology
1572
The goals of the cSTART storage ring at Karlsruhe Institute of Technology (KIT) are to demonstrate the storage of ultra-short electron bunches and study their non-equilibrium dynamics. Furthermore, it aims to study the application of laser-plasma accelerators (LPAs) as injectors for storage rings. To allow the direct injection of LPA bunches with comparably large energy spread, cSTART has a specifically designed flexible magnetic lattice with large momentum acceptance. The non-ramping ring will also use the existing linac-based accelerator FLUTE as injector for commissioning and experiments with controlled beam parameters. In 2024, the collaboration between KIT, RI Research Instruments GmbH, and its subcontractors completed the Technical Design Report (TDR), followed by the Final Design Report (FDR) in spring 2026. The magnets and power supplies for the injection line (IL), which will connect FLUTE to the storgae ring, are already available in KIT’s inventory. Meanwhile, the magnets, power supplies, and vacuum chambers for the storgae ring are currently in production. This contribution provides an overview of the current status an outlines the next steps of the cSTART project.
Paper: TUP3016
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-TUP3016
About: Received: 13 May 2026 — Revised: 22 May 2026 — Issue date: 22 May 2026
TUP3017
Towards integrated diagnostics for multi-stage dielectric laser acceleration: a conceptual study
1576
Dielectric laser acceleration (DLA) enables compact, chip-scale accelerators. Recent demonstrations of multi-stage acceleration, alternating-phase focusing and interaction length in the millimeter range in dielectric nanostructures have verified the scalability of DLA concepts but the compactness places extreme demands on beam diagnostics due to submicron apertures, sub-fs bunch lengths and strong non-linear dynamics. To support the development of multi-stage structures and precise matching between stages, we explore diagnostic concepts that use the dielectric structures themselves. Tailored gratings can encode beam properties—such as bunch length—into emitted radiation, providing compact, high-resolution, on-chip diagnostics. Additionally to these hardware approaches, we propose to apply a machine-learning–based virtual diagnostic for DLA experiments. A neural network trained on 6D tracking simulations reconstructs key interaction parameters from the post-DLA electron beam and intermediate diagnostics and enables real-time optimization even in strongly non-linear regimes. Combining integrated dielectric diagnostics with ML-based reconstruction provides a scalable strategy for precise characterization and control of next-generation dielectric laser accelerators.
Paper: TUP3017
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-TUP3017
About: Received: 13 May 2026 — Revised: 17 May 2026 — Accepted: 21 May 2026 — Issue date: 22 May 2026
TUP3033
Simulation of plasma dechirper and lens for laser wakefield acceleration
1592
The quality of electron beams produced by Laser Wakefield Acceleration (LWFA), is controlled through laser parameters and plasma density distribution during the injection and acceleration phases, and in some cases, a specific device providing beam selection or shaping to achieve the electron beam quality needed the envisaged application. A major challenge in the generation of LWFA electron sources is reducing energy and transverse momentum spread to enhance spectral brightness, requiring advanced techniques to optimize beam quality. We design plasma density profiles to control electron injection and acceleration, specifically to improve the electron beam phase space characteristics in a compact way. This works presents our numerical study using Computational Fluid Dynamics (CFD) and Particle-In-Cell (PIC) simulations. These simulation results are in good agreement with experimental results obtained at Helmholtz-Zentrum Dresden-Rossendorf.
Paper: TUP3033
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-TUP3033
About: Received: 13 May 2026 — Revised: 20 May 2026 — Issue date: 22 May 2026
TUP3034
Analytical calculation of transverse emittance and Twiss parameters
1596
Achieving plasma-based accelerators for users demands careful control not only of the beam energy and energy spread, but also of transverse beam properties such as emittance, size, and divergence. Since plasma-based accelerators typically produce beams with significantly larger energy spread and emittance than conventional RF accelerators, several questions remain to be addressed, particularly, the transverse beam dynamics. In this article, it is presented an analytical description of the transverse beam properties evolution in a constant-focusing channel representing a plasma density plateau assuming a finite energy spread. The resulting expressions provide qualitative and quantitative guide to understand the transverse beam dynamics under these conditions.
Paper: TUP3034
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-TUP3034
About: Received: 15 Apr 2026 — Revised: 20 May 2026 — Accepted: 21 May 2026 — Issue date: 22 May 2026
TUP3035
Nonlinear transverse beam dynamics in AWAKE Run 2c
1600
The AWAKE experiment harnesses the 400 GeV proton beam from the CERN SPS to drive plasma wakefields, which in turn accelerate a witness bunch of electrons to high energy. Upgrades are currently being carried out to facilitate the experimental programme of Run 2c, which includes control of the witness bunch quality during acceleration. We here present the first full simulations of the beam–plasma interaction for AWAKE Run 2c, including self-modulation of the proton drive beam and the acceleration of the witness bunch in the wakefields of the resulting train of driver microbunches. We demonstrate that the length of the proton drive beam has a significant impact on the transverse wakefield dynamics which impact the quality of the accelerated electron witness. These simulations inform the choice of parameters for the experiment.
Paper: TUP3035
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-TUP3035
About: Received: 12 May 2026 — Revised: 20 May 2026 — Accepted: 21 May 2026 — Issue date: 22 May 2026
TUP3041
Density downramp injection into a discharge-based plasma acceleration stage
1608
Electron bunches internally injected into plasma accelerators reach relativistic energies in giga-volt-per-metre-level fields, reducing emittance growth due to space charge and ultimately yielding high-brightness beams.Density downramps with steep gradients have provided an effective method of controllable injection into beam-driven plasma-wakefield accelerators, but previously have relied on the fields of an intense particle beam or laser to preionise the acceleration stage. Here, injection using downramps formed via optical ionisation is experimentally shown to be compatible with discharge-based-acceleration stages, producing bunches with up to six times higher energy than with laser-only preionisation. Results demonstrating injection of charge using a purely discharge-preionised acceleration stage and a low-energy injection laser suggest the feasibility of a scalable, high-repetition-rate injection stage—potentially attractive for high-average-power applications.
Paper: TUP3041
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-TUP3041
About: Received: 18 Apr 2026 — Revised: 20 May 2026 — Accepted: 21 May 2026 — Issue date: 22 May 2026
TUP3043
A full-energy electron injector for the EIC based on proton-driven plasma-wakefield acceleration
1612
The Electron-Ion Collider (EIC) is presently under construction at Brookhaven National Laboratory, and will collide electrons with an energy of up to 18 GeV with hadrons of up to 275 GeV. In this work we evaluate the feasibility of using proton-driven plasma wakefield acceleration to accelerate electron bunches to full energy for injection into the EIC Electron Storage Ring. Particle-in-cell simulations are used to identify a scheme which allows the acceleration of electron bunches with high charge and low energy spread, building on previous studies which investigated the potential energy gain. The RHIC “BLUE RING”, which accelerates hadrons in the same direction as the electrons of the EIC, can be exploited to drive the plasma wakefields, offering the potential to significantly reduce the capital cost of the EIC facility. We show that by increasing bunch population to $3\times 10^{11}$, and moderate compression of the drive bunch to 2.5 cm, high accelerating fields can be achieved by exploiting the self-modulation of the proton beam, as harnessed by the Advanced Wakefield Experiment (AWAKE) project at CERN. To facilitate the use of a plasma discharge, we consider the possibility of using different ions, instead of rubidium.
Paper: TUP3043
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-TUP3043
About: Received: 13 May 2026 — Revised: 20 May 2026 — Accepted: 21 May 2026 — Issue date: 22 May 2026
TUP3044
Gaussian Process Regression and Bayesian Optimization for a 40-90 MeV Laser-Plasma Injector for the cSTART Storage Ring
1616
Laser-plasma accelerators (LPAs) generate ultrashort high intensity electron bunches from a compact source size. At the Karlsruhe Institute of Technology (KIT), we will use an LPA as one of the injectors for the compact, high-momentum acceptance, non-equilibrium storage ring cSTART. The LPA injector with a length of only a few millimeters will be optimized to match the cSTART operation beam energy of 40-90 MeV. It will be based on an ionization trapping scheme in combination with a tailored plasma density profile to produce an electron beam with small energy spread that maximizes the spectral charge density at our target energy, which is (for LPAs) comparably low. Moreover, the LPA injector must produce controlled electron beams with high shot-to-shot stability and avoid high-energy tails. These goals can be achieved largely by the detailed design of the plasma density profile and the laser pulse parameters. In an LPA, small changes across the high-dimensional parameter space can have a disproportional influence on overall performance. To find parameters for stable high-quality LPA beams, we perform particle-in-cell (PIC) simulations and implement a machine-learning driven approach by using Bayesian Optimization (BO) based on Gaussian Process Regression (GPR). This procedure allows us to both optimize our gas target design and characterize the effects of the interaction parameters, giving us a functional LPA with a simple tuning mechanism.
Paper: TUP3044
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-TUP3044
About: Received: 01 Apr 2026 — Revised: 22 May 2026 — Issue date: 22 May 2026
TUP3045
Fixed-Field alternating gradient transport line for laser-plasma accelerated electrons
1620
A transport line for laser-plasma accelerated electrons is proposed based on the fixed-field alternating gradient accelerator (FFA) concept. To accommodate the large LPA energy spread and match the beam to a transverse gradient undulator (TGU), the lattice incorporates matching cells with high-temperature superconducting quadrupoles providing gradients up to 220 T/m, along with a compact FFA dispersion creator. This configuration allows strong focusing and dispersion tailoring within a compact geometry. The study represents an initial step toward demonstrating the feasibility of FFA-based dispersion management for LPA-driven light sources, while outlining the requirements of further optimization.
Paper: TUP3045
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-TUP3045
About: Received: 11 May 2026 — Revised: 17 May 2026 — Accepted: 17 May 2026 — Issue date: 22 May 2026
TUP3046
Laser-plasma electron injector for the cSTART storage ring
1624
Laser-plasma accelerators (LPAs) generate ultrashort, high-intensity electron bunches in a compact form factor. At Karlsruhe Institute of Technology (KIT), we are developing an LPA for direct injection into a specifically built storage ring with high momentum acceptance. The cSTART storage ring (compact storage ring for accelerator research and technology) can be tuned to energies between 50 – 90 MeV, and its lattice is designed to accept electron beams with +/- 4% energy spread. Furthermore, the ring lattice can be set up for the storage of ultrashort electron bunches. The LPA electron injector must be readily tunable to match the storage ring parameters. This contribution reports proof-of-concept experiments that demonstrate the generation of high-quality LPA electron beams with parameters that fulfill the cSTART requirements.
Paper: TUP3046
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-TUP3046
About: Received: 12 May 2026 — Revised: 17 May 2026 — Accepted: 17 May 2026 — Issue date: 22 May 2026
TUP3060
Breakthroughs in EuPRAXIA-DN on the path to next-generation plasma accelerators
1631
The EuPRAXIA Doctoral Network (EuPRAXIA-DN) has delivered major advances over the past year in laser–plasma physics, beam diagnostics, and compact radiation-source concepts. Experiments demonstrated superradiant nonlinear Thomson scattering, showing collective enhancement of radiation from relativistic electron bunches interacting with azimuthally polarized laser pulses. Diagnostics developments include new methods to retrieve femtosecond longitudinal bunch profiles from coherent THz transition-radiation images, as well as preliminary shot-to-shot charge measurements in high-EMP environments using diamond detectors, supported by high-precision characterization of the detector. This poster presents these important results in the context of the broader EuPRAXIA-DN project. It highlights how coordinated R&D, structured training, cross-sector international secondments, EuPRAXIA Schools and Camps, as well as hands-on training at world-class research facilities accelerate the technological progress and talent pipeline required for compact, user-ready plasma accelerators.
Paper: TUP3060
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-TUP3060
About: Received: 10 May 2026 — Revised: 17 May 2026 — Accepted: 21 May 2026 — Issue date: 22 May 2026
TUP3061
Challenges of moderate energy external injection into Laser-driven Wakefield Accelerators
1635
Laser Wakefield Acceleration (LWFA) enables GV/m acceleration gradients, promising compact accelerator designs with advantages in cost, environmental impact and portability. Standard LWFA schemes can suffer from poor shot-to-shot stability and beam quality, resulting in broad energy spectrums, beam current variations, high emittance and limited intensity. External injection schemes attempt to overcome such challenges by treating the LWFA stage as purely an accelerating structure and not as a source. Motivated by the pursuit of compactness, external injection of moderate-energy (< 60 MeV) electron beams into plasma will be explored using the Fourier-Bessel Particle-In-Cell (FBPIC) code. The sensitivity of the final beam quality to sub-optimal injection parameters will be explored. Bayesian optimisation is employed to assess whether sub-optimal injection parameters can be compensated for with laser and plasma parameters. This investigation presents working points from which future compact external injection designs can be optimised.
Paper: TUP3061
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-TUP3061
About: Received: 12 May 2026 — Revised: 16 May 2026 — Accepted: 21 May 2026 — Issue date: 22 May 2026
TUP3063
Performance analysis of a Mach-Zehnder interferometer using synthetic interferograms
1639
In this work, we assess the performance and limitations of Mach-Zehnder interferometry for plasma diagnostics using a fully synthetic, numerically generated dataset. We explore regions of parameter space that are difficult to access experimentally, including fringe behaviour under different plasma density profiles, the dynamic range of measurable phase shifts, and the resolution limits for low-density plasmas. By introducing controlled phase errors and noise, we quantify the robustness of common phase retrieval and phase unwrapping algorithms and identify the conditions under which these methods succeed or fail. Our results provide practical design guidelines for optimising interferometric measurements across a wide range of plasma conditions.
Paper: TUP3063
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-TUP3063
About: Received: 12 May 2026 — Revised: 16 May 2026 — Accepted: 16 May 2026 — Issue date: 22 May 2026
TUP3071
Optimized design of a C-band 100 MeV electron LINAC for FLASH radiotherapy
1654
Electron LINACs are key tools for radiotherapy. Conventional low-energy ones can treat only superficial tumors. Achieving Very High Energy Electrons (VHEE, >100 MeV) enables treatment of deep-seated tumors. Furthermore, electrons are well-suited for delivering Ultra-High Dose Rates (UHDR) required for FLASH therapy, which improves healthy-tissue sparing. Combining VHEE and FLASH in a hospital environment represents an important step forward for Radiotherapy. In the context of the SAFEST project at Sapienza, this work presents a compact and cost-effective accelerator layout capable of delivering hundreds of nC at 100 MeV within tens of pulses over 1 ms of irradiation. The design emphasizes efficient RF power usage through high-efficiency C-band structures and a pulse compressor. Beam dynamics simulations and low-power RF tests validate the approach. A strong focus is placed on flattening the compressor signal, which must remain stable over 1 mus to accommodate electrons from a triode thermionic gun, a compact and economical source for this accelerator. The resulting 3-m linac, powered by a single 20-MW klystron, shows strong potential for future hospital-based FLASH VHEE treatments.
Paper: TUP3071
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-TUP3071
About: Received: 15 Apr 2026 — Revised: 18 May 2026 — Accepted: 21 May 2026 — Issue date: 22 May 2026
TUP3075
Evidence for RF breakdowns causing surface anomalies on caesium Telluride cathodes at Clara
1666
The Compact Linear Accelerator for Research and Applications (CLARA) at Daresbury Laboratory has recently undertaken an upgrade of its photocathodes from using a copper emission surface to using caesium telluride (Cs\textsubscript{2}Te). During the conditioning of the first Cs\textsubscript{2}Te cathode a significant number of RF breakdowns were detected, and so that cathode was replaced; subsequent inspection of the cathode following removal identified a number of surface defects. To better study the second cathode, a diagnostic camera was used to collect images of the surface \textit{in situ} during RF conditioning; the frequent formation over time of surface defects was observed. In this paper we present a statistical analysis of the breakdown events and surface image data, utilizing cross-correlation of the signal derivatives to account for cumulative trends. The analysis reveals a correlation between the rate of defect formation and the incidence of RF breakdowns, with a Pearson coefficient of $r = 0.59$ at zero time lag. These results provide quantitative evidence that RF breakdown events are the likely driver of surface morphology changes on Cs\textsubscript{2}Te cathodes.
Paper: TUP3075
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-TUP3075
About: Received: 15 May 2026 — Revised: 18 May 2026 — Accepted: 20 May 2026 — Issue date: 22 May 2026
TUP3078
Laser wakefield acceleration in carbon nanotube bundles
1674
Laser wakefield acceleration (LWFA) can produce accelerating fields of several hundred GV/m, greatly reducing accelerator size and cost. Carbon nanotube (CNT) bundles, featuring high plasma density (>10$^{19}$ cm$^{-3}$), tunable effective density, excellent thermal properties, and empty channels that enable laser propagation, have attracted interest as solid-state plasma sources. Previous studies suggested that CNT-based structures can increase the acceleration field to the TV/m range, making them promising for compact radiation sources and radiotherapy. However, the insufficient beam quality still limits their broader application. In this work, we model a hollow solid-state plasma channel composed of CNT bundles. A 2 PW laser from the ELI-ALPS High-Field Laser facility is injected into the channel, where self-injected electrons at the nC-scale are trapped and accelerated in a TV/m field, as shown by particle-in-cell simulations with WarpX. Comparing with previous LWFA results using solid-state targets, we obtain an electron beam with > 2 nC charge and > 100 MeV mean energy, while achieving an unprecedented energy spread < 5%, by tuning the filling factor, bundle diameter, and gap size. We clarify that the large energy spread in the overdense plasma arises from the laser-plasma instability. In addition, we observe strong scattering within the overdense bundle walls. We further aim to investigate how the scattering affects the laser field and, consequently, the beam quality.
Paper: TUP3078
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-TUP3078
About: Received: 11 May 2026 — Revised: 20 May 2026 — Accepted: 21 May 2026 — Issue date: 22 May 2026
TUP3079
High current accelerator-driven neutron source platform overview
1678
ESS-Bilbao, JCNS, and LLB joined forces to develop Europe’s first HICANS Platform (HiCANS stands for "High Current Accelerator-driven Neutron Source"). This project aims to integrate the high current proton accelerator system, currently under construction at ESS Bilbao, with the target-moderator-reflector unit that has been successfully built and operated at Forschungszentrum Jülich, and the HERMES reflectometer and Be target owned by LLB. This facility intends to validate and demonstrate the technological developments that will take part of these medium-flux neutron sources. In this demonstrator, the first stage of the ARGITU source will be used to produce a pulsed proton beam with an energy of 3 MeV and a period of 30 Hz to hit a Lithium target, generating neutrons that are moderated at the desired thermal and cold energy ranges that will be utilized by the HERMES neutron reflectometer. The instrument has undergone upgrades and improvements, since it was first installed in the COSY platform, such as the installation of a methane moderator, which has increased the reflectivity signal by a factor of two. The installation of the instrument in ESS-Bilbao premises will help to continue its experimental program, as well as paving the way to future integration of neutron scattering and imaging instruments at higher accelerator power.
Paper: TUP3079
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-TUP3079
About: Received: 12 May 2026 — Revised: 16 May 2026 — Accepted: 17 May 2026 — Issue date: 22 May 2026
TUP7009
Operation of the Kara booster in storage-ring mode for accelerator studies and system development
1689
The Karlsruhe Research Accelerator (KARA) booster synchrotron, normally used to accelerate electrons from 53 MeV to 500 MeV for injection into the KARA storage ring, has recently been successfully operated in a stand-alone storage ring mode. This capability was enabled by the modernization of its magnet power supplies and their integration into an EPICS-based control system. Operating the booster in this mode provides a flexible platform for accelerator physics studies, including the development of energy-ramping procedures, characterization of magnet hysteresis effects, and verification of control strategies under low-energy storage conditions. Initial commissioning demonstrated stable beam storage at several energies up to 500 MeV. The future compact storage ring cSTART, designed for energies of 50-90 MeV, is currently being constructed at KIT. The new power supplies allow preliminary experiments to be conducted across this energy level in the KARA Booster, enabling studies of beam and machine characterizations under realistic conditions. Additionally, the ability to store beam up to 500 MeV supports tests relevant for the KARA storage ring. This mode establishes the booster as a compact and flexible experimental platform prior to deployment in cSTART and the main KARA storage ring. Future work will focus on beam dynamics and diagnostics in the lower energy region with reduced radiation damping, as well as optimization of ramping cycles for stable injector operation.
Paper: TUP7009
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-TUP7009
About: Received: 13 May 2026 — Revised: 18 May 2026 — Accepted: 21 May 2026 — Issue date: 22 May 2026
TUP7011
The TEX facility upgrade at INFN-LNF
1695
The TEX (TEst stand for X band) facility at INFN-LNF is a high-power RF test stand dedicated to the qualification of X-band components and accelerating structures for the EuPRAXIA@SPARC_LAB linac and related projects. An upgrade program is underway to extend its capabilities by increasing the available peak and average power, repetition rate, and operational flexibility for both X-band (11.994 GHz) and C-band (5.712 GHz) operation. The major intervention includes the installation of two new high-repetition-rate RF sources, one X-band and one C-band, together with dedicated waveguide distribution networks and improved diagnostics for breakdown detection, pulse shaping, and long-term stability studies. Moreover, the C-band station, with the integration in the bunker of a C-band RF photo-gun developed within the IFAST project, will serve as the first testbed for a full C-band high-brightness photoinjector, enabling experimental validation of compact injector schemes. These enhancements will allow parallel conditioning stations, advanced high-gradient tests of accelerating structures, and accelerated validation of RF components under realistic operating conditions for next-generation accelerators. The contribution will describe in detail the upgrade of the TEX facility and its future perspectives.
Paper: TUP7011
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-TUP7011
About: Received: 13 May 2026 — Revised: 21 May 2026 — Accepted: 21 May 2026 — Issue date: 22 May 2026
TUP7307
Progress on the normal conducting RF cavities for EIC hadron storage ring
1711
The Normal-Conducting Radiofrequency (NCRF) systems for the Electron-Ion Collider Hadron Storage Ring (EIC HSR) comprise four unique cavity systems. These systems include a 24.6 MHz capture and acceleration system, a combined 49.2 MHz and 98.4 MHz bunch splitting system, and a 197 MHz storage system for collider operations. All systems have successfully passed their final design reviews, and the detailed drawings are currently being completed for procurement. This paper reports on the recent progress achieved across these NCRF cavity systems.
Paper: TUP7307
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-TUP7307
About: Received: 14 May 2026 — Revised: 18 May 2026 — Accepted: 20 May 2026 — Issue date: 22 May 2026
TUP7312
Progress Towards RF Conditioning of Low-Loss Couplers for a Conduction-Cooled Cryomodule
1723
This work presents current progress on the conditioning of two new 25 kW couplers optimized for use in a compact, conduction-cooled SRF cryomodule. A connecting waveguide, previously used for conditioning the 805 MHz SNS couplers, was altered for use at 915 MHz. The necessary modifications were determined via RF modeling, while thermal analysis results identified additional cooling requirements during RF conditioning and provided insight about potential higher-power operation. Initial low-power conditioning will be performed with a 2.5 kW solid-state amplifier, with plans to use an industrial magnetron for RF conditioning at 25 kW in the near future.
Paper: TUP7312
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-TUP7312
About: Received: 13 May 2026 — Revised: 15 May 2026 — Accepted: 16 May 2026 — Issue date: 22 May 2026
TUP7313
High Gradient Testing of a Two-Cell C-band Accelerator Cavity with NiCr Higher-Order Mode Absorbers
1727
This presentation will report on the status of fabrication, tuning, and high gradient testing of a two-cell accelerator cavity with distributed coupling and higher-order-mode (HOM) damping slots covered with nickel-chromium (NiCr) absorbing material. The cavity is designed with a specific purpose to demonstrate applicability of NiCr material for damping HOMs in a C-band distributed-coupling accelerating structure, such as may be used in a C3 linear collider. The purpose of this experiment is to conduct a simple high-power test to understand fabrication challenges for the cavity with NiCr HOM absorbers and examine performance of the NiCr coating during high power conditioning. We will report the detailed electromagnetic and engineering design of the cavity, fabrication, cold testing, tuning and the results of high gradient testing at the CERF-NM C-band high gradient test facility at Los Alamos National Laboratory.
Paper: TUP7313
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-TUP7313
About: Received: 13 May 2026 — Revised: 15 May 2026 — Accepted: 17 May 2026 — Issue date: 22 May 2026
TUP7317
Cavity optimizations and beam dynamics simulations for LANSCE upgrades
1739
Distributed drive linear accelerators (DDLs), in which each accelerating cell is independently powered, offer the flexibility to set the phase and amplitude of the RF fields in each cavity individually. In the limiting case of a linac composed entirely of independently-driven single-cell cavities, the RF power required per individual cavity can be a good match to the capabilities of solid-state amplifiers. For these reasons, the possibility of upgrading the current coupled cavity linac (CCL) in the LANSCE accelerator at Los Alamos National Laboratory to a DDL architecture is being investigated. Here we report results from cell profile optimizations and beam dynamics simulations carried out to study the potential advantages of a DDL architecture in the LANSCE accelerator.
Paper: TUP7317
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-TUP7317
About: Received: 13 May 2026 — Revised: 18 May 2026 — Accepted: 21 May 2026 — Issue date: 22 May 2026
TUP7318
Ceramic Enhanced Accelerating Structure (CEAS) optimization for improved shunt impedance
1743
We present a COMSOL Multiphysics®–based workflow, using the Optimization Module, to increase RF cavity shunt impedance (Rsh) by systematically reshaping the nose cones. The cavity being optimized is utilizing the Ceramic Enhanced Accelerating Structure (CEAS) approach with a ceramic tube insert at the inner electric field zero of the TM020 mode, which increases the efficiency by reducing power dissipation. The CEAS concept, combined with the improved shunt impedance from nose cone optimization, yields a particularly efficient cavity. The cavity is parameterized with smooth geometric variables (nose tip radius, cone angle, gap, fillets). This optimization maximizes Rsh subject to frequency locking and engineering limits based on the cavity geometry. Eigen-frequency studies are used as the primary optimization tool producing a field map of the desired TM020 mode as well as the power dissipated on the walls and within the ceramic material. Post processing optimization computes Rsh and peak nose cone field from the electric field profile and losses. Single cell studies show higher Rsh without degrading cavity performance; optimal profiles provide moderating curvature to control local field enhancement.
Paper: TUP7318
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-TUP7318
About: Received: 18 May 2026 — Revised: 20 May 2026 — Accepted: 21 May 2026 — Issue date: 22 May 2026
TUP7319
Design and test of an X-band cavity for short-pulse RF breakdown studies
1745
High-gradient operation of normal-conducting radiofrequency (RF) cavities is fundamentally limited by RF breakdown, a phenomenon driven by processes including field emission, surface heating, multipacting and plasma formation. Recent studies have indicated that operating the cavities in a short-pulse regime, with RF pulses of only a few nanoseconds long, can modify the onset and dynamics of breakdown. In particular, short pulses are instrumental in limiting multipactor-driven electron growth and reducing field-emission-induced Joule heating on cavity surfaces. However, systematic experimental investigations into these dynamics are limited. We present the design of a dedicated experiment using a single-cell high-gradient X-band cavity, to be tested at the Argonne Wakefield Accelerator (AWA), for studying RF breakdown with short pulses. The experiment will employ short, adjustable RF pulses in the few-nanosecond range. We will detail the cavity design optimized for short-pulse operation, the planned operating parameter space for the measurements, and the diagnostics for time-resolved dark current and RF signals, with the ultimate goal of quantifying how breakdown behavior changes as a function of pulse length and field gradient.
Paper: TUP7319
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-TUP7319
About: Received: 13 May 2026 — Revised: 19 May 2026 — Accepted: 21 May 2026 — Issue date: 22 May 2026
TUP7340
Understanding the connections between grain growth and flux expulsion in low RRR niobium SRF cavities
1760
The SRF community has shown that high temperature annealing can improve the flux expulsion of niobium cavities during cooldown. The required temperature will vary between cavities and different batches of material, typically around 800 C and up to 1000 C. However, for niobium with a low residual resistance ratio (RRR), even 1000 C is not enough to improve its poor flux expulsion. The purpose of this study is to observe the grain growth behavior of low RRR niobium coupons subjected to high temperature annealing to identify the mechanism for improving flux expulsion in low RRR cavities. We anneal the low RRR material up to 1200 C to understand the limits of flux expulsion performance. We observe that low RRR material experiences less grain growth than high RRR when annealed at the same temperature. We search for the limitations to grain growth in low RRR material and develop a diagnostic based on grain structure to determine the appropriate recipe for good flux expulsion. The results of this study have the potential to unlock a new understanding on SRF materials and enable the next generation of high Q/high gradient surface treatments.
Paper: TUP7340
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-TUP7340
About: Received: 22 May 2026 — Revised: 22 May 2026 — Issue date: 22 May 2026
TUP7346
High-power amplifier considerations for testing the LAMP RFQ and first DTL cavity
1768
As part of the LANSCE Accelerator Modernization Project (LAMP), critical portions of the proposed accelerator will be tested as proof of concept and aid in planning the installation of LAMP at Los Alamos Neutron Science Center. As part of this demonstration, the radio frequency quadrupole (RFQ) and the first drift-tube linac (DTL) cavity will be tested with beam. For this purpose, high-power RF amplifiers are being designed to meet the testing demands. This is a description of the requirements of these amplifiers and how the design is intended to meet them.
Paper: TUP7346
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-TUP7346
About: Received: 15 May 2026 — Revised: 19 May 2026 — Accepted: 20 May 2026 — Issue date: 22 May 2026
TUP7347
High power GaN amplifier development for coupled-cavity Linac at LANSCE
1771
The Los Alamos Neutron Science Center uses a coupled-cavity linac to accelerate H- ions from 100 to 800 MeV. It is powered by forty-four 1.25 MW 805 MHz klystrons, each capable of 150 kW of average power. A prototype solid-state amplifier that meets these requirements is in development. Commercial silicon LDMOS transistors have reduced power above 600 MHz and are also limited by the maximum drain to source breakdown voltage. We are using high voltage Gallium Nitride (GaN) on Silicon Carbide (SiC) high electron mobility transistors (HEMT) to reduce the number of active devices and the complexity of power combing smaller amplifiers. These wide bandgap semiconductors can operate at high channel temperatures around 200 degC without shortened life. We are testing new devices up 5 kW of peak power at 100 volts. Operating in saturation mode, outphasing modulation is used to maintain high device efficiency to reduce thermal dissipation, compared to conventional class AB linear amplifiers. The power supply requires stored energy with a capacitor bank. Power combining uses a combination of 2-way Gysel, 40-way radial and magic tee combiners in waveguide.
Paper: TUP7347
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-TUP7347
About: Received: 12 May 2026 — Revised: 18 May 2026 — Accepted: 21 May 2026 — Issue date: 22 May 2026
TUP7370
Status update of permanent magnet radiation resiliency studies at CEBAF
1787
The proposed energy upgrade of the Continuous Electron Beam Accelerator Facility (CEBAF) incorporates Fixed-Field Alternating-gradient (FFA) arcs utilizing permanent magnet technology. Given the radiation environment within the CEBAF tunnel enclosure, validating the long-term magnetic stability of these materials is a critical step for the project's technical feasibility. This contribution presents an overview of the ongoing permanent magnet radiation resiliency program at Jefferson Lab. We briefly review the experimental methodology used to monitor demagnetization in situ and summarize the operational experience from the initial data-taking campaign. Furthermore, we discuss the upgrades implemented for the second exposure campaign, currently underway, which aims to refine dose correlation and reduce systematic uncertainties. We report on the general status of the program and the roadmap for certifying permanent magnet optics for the proposed upgrade energies.
Paper: TUP7370
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-TUP7370
About: Received: 01 May 2026 — Revised: 17 May 2026 — Accepted: 17 May 2026 — Issue date: 22 May 2026
TUP7602
High-power testing of X-Band high-gradient structures and RF components at the Mel-BOX facility
1791
Mel-BOX, the reinstallation of half of CERN’s XBOX3 test stand, has been operating at the University of Melbourne’s X-LAB for over few years. The facility provides 12 GHz high-power pulsed RF for testing high-gradient travelling-wave accelerating structures and associated X-band components relevant to the CLIC baseline. Two TD24 structures, previously conditioned at CERN and stored for five years, were successfully reconditioned and tested at Mel-BOX, demonstrating that prolonged storage does not significantly degrade high-gradient performance. Additional high-power RF campaigns were carried out on a compact pillbox-type RF window supporting travelling-wave fields in the ceramic, high-power loads fabricated using 3D-printed titanium and long stainless-steel sections, and a set of SLED-I pulse compressors featuring a newly designed removable copper tuning plate. Each pulse-compressor cavity was independently tuned prior to conditioning, enabling stable operation and reproducible pulse compression during high-power tests. These activities establish Mel-BOX as a dedicated and mature X-band platform for advancing high-gradient accelerator technology and supporting the development of compact accelerator systems for medical, industrial, and scientific applications.
Paper: TUP7602
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-TUP7602
About: Received: 12 May 2026 — Revised: 19 May 2026 — Accepted: 21 May 2026 — Issue date: 22 May 2026
TUP7603
The design of the quasi-traveling wave parallel-coupled structure
1795
A quasi-traveling-wave parallel-coupled (TWPC) accelerating structure is proposed for compact linacs requiring both high RF efficiency and improved frequency tolerance. In contrast to conventional standing-wave parallel-coupled structures, the proposed topology enables partial reflected power generated under detuned conditions to be redistributed through the feeding manifold and reabsorbed by downstream cavities. A 12-cell x-band TWPC structure operating in the $5\pi/6$ mode was designed using a cascaded waveguide feeding network. The structure achieves approximately 95\% unloaded RF power utilization with a 1.8 MW input power level. Beam dynamics simulations predict a 5 MeV energy gain with a 95%-bandwidth of 1.4 MHz.
Paper: TUP7603
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-TUP7603
About: Received: 12 May 2026 — Revised: 18 May 2026 — Accepted: 21 May 2026 — Issue date: 22 May 2026
TUP7611
High-power experimental study on a compact C-band spherical pulse compressor
1801
In order to enhance the accelerating gradient of the 1-meter C-band Traveling-wave accelerating structure prototype, as well as meet the physics requirements on the linear injector of the proposed Jinhua light source (JHLS) project, a compact C-band spherical pulse compressor was developed to boost the output power from klystron. This pulse compressor excites TE114 modes inside the spherical cavity by coupling energy via a compact polarized coupler. In the preliminary high-power conditioning, an output pulse of 8.7 MW, 2.6 μs from the klystron was compressed to 53.9 MW, 400 ns pulse through this pulse compressor, thereby enabling an average power gain of 4.2. An amplitude modulation approach was adopted to generate a flattop output pulse, an average power gain of 3.78 with a full-width at half-maximum (FWHM) pulse duration of 353 ns was achieved after modulation.
Paper: TUP7611
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-TUP7611
About: Received: 15 Apr 2026 — Revised: 18 May 2026 — Accepted: 21 May 2026 — Issue date: 22 May 2026
TUP7615
Design, fabrication and low-power measurements of an X-band parallel-coupled accelerating structure
1807
To meet the requirement for high-gradient accelerating structures in future compact accelerator systems, this work presents the design, fabrication, and preliminary testing of an X-band 11.424 GHz parallel-coupled accelerating structure. The structure consists of 16 cells and operates in the π mode, with an optimal filling time of approximately 50 ns under over-coupling conditions. The prototype has been successfully fabricated, followed by low-power measurements and bead-pull field distribution. The results show that machining errors are within 5 µm, satisfying the tolerance requirements. These results provide a solid foundation for the subsequent high-power tests.
Paper: TUP7615
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-TUP7615
About: Received: 15 Apr 2026 — Revised: 14 May 2026 — Accepted: 17 May 2026 — Issue date: 22 May 2026
TUP7618
Design of an X-band compact mode converter for converting TE10 mode to TE01 mode
1813
This paper presents the design of a compact and efficient rectangular waveguide TE10 to circular waveguide TE01 mode converter operating in the X-band. By incorporating two choke slots, the design achieves a high-purity circular waveguide TE01 mode. The optimized results show that at the operating frequency of 11.424 GHz, the conversion efficiency for the circular waveguide TE01 mode is calculated to be approximately 100%, while the reflection coefficient is better than -50 dB. The bandwidth reaches more than 260 MHz for the transmission coefficient while the bandwidth is approximately 210 MHz for the reflection coefficient better than -20 dB.
Paper: TUP7618
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-TUP7618
About: Received: 09 May 2026 — Revised: 17 May 2026 — Accepted: 17 May 2026 — Issue date: 22 May 2026
TUP7622
Design of a compact energy-tunable X-band linac for FLASH radiotherapy
1820
FLASH radiotherapy (FLASH-RT) demonstrates the potential to maintain tumor control while reducing normal tissue toxicity through ultra-high dose rates. This paper presents a novel compact X-band (9.3 GHz) accelerating system designed for FLASH-RT applications. The core innovation is a dual-structure common-source architecture: the first structure provides a fixed 6 MeV energy gain, while the second enables independent continuous energy adjustment from 0 to 6 MeV via a tunable microwave network. This design allows a single klystron to drive both structures without mutual interference during energy adjustment. The system length is only approximately 1 meter. The design process integrates radio frequency (RF) simulation and beam dynamics simulation in a coupled manner, with particular focus on the bunching section optimization. This compact system provides a high-performance accelerator solution for next-generation FLASH radiotherapy, especially for intraoperative applications requiring rapid energy adjustment.
Paper: TUP7622
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-TUP7622
About: Received: 10 May 2026 — Revised: 18 May 2026 — Accepted: 21 May 2026 — Issue date: 22 May 2026
TUP7623
Design and implementation of ridge waveguides for dual-mode microwave structure
1823
The dual-mode microwave structure is receiving increasing attention and research. In the application of dual-mode structures, it is necessary to solve the problem feeding microwave power at different frequencies. One method is to use complex waveguide components, such as first and second harmonic photocathode bimodal gun, which consists of the assembly of the directional coupler and the mode launcher. The structure combines the S-band and C-band power into a waveguide and feeds them into the dual-mode electronic gun. Another method is to use ridge waveguide to achieve selectable transmission or blocking of specific frequency. Currently, the ridge waveguide has been applied to dual-mode deflecting structure. This paper presents a X-band bandpass filter has been engineered to achieve a power reflection level of less than -30 dB at 12 GHz and a power transmission level of less than -40 dB at 24 GHz.
Paper: TUP7623
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-TUP7623
About: Received: 10 May 2026 — Revised: 16 May 2026 — Accepted: 21 May 2026 — Issue date: 22 May 2026
TUP7625
Application of magnetic-alloy-loaded cavities beyond 10MHz
1830
Magnetic-Alloy-loaded cavities have been used for many applications; beam accelerations of high-intensity proton and heavy ion beams, beam manipulations, medical accelerators and anti-proton decelerations. The material has a large permeability and the cavities have bandwidth below approximately 10 MHz. Using an external inductor for reducing the effective inductance of a cavity system, the cavity bandwidth can be moved beyond 10 MHz. The higher harmonic cavity is required in J-PARC Main Ring to enlarge the longitudinal beam emittance before reaching the flat-top energy. For the slow extraction, the emittance growth will be inevitable to suppress the beam instability. For Hyper-Kamiokande neutrino experiment, high-intensity beam with lower peak current will be required to avoid the event-pile-up at a new intermediate detector (IWCD). In this paper, we present the emittance control scenario with the cavity, beam effects on it, and design of a new VHF RF system.
Paper: TUP7625
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-TUP7625
About: Received: 11 May 2026 — Revised: 21 May 2026 — Accepted: 21 May 2026 — Issue date: 22 May 2026
TUP7627
Beam test of C-band Compact accelerating structure made of longitudinally-split two halves
1838
Our 6 MeV medical C-band accelerating structure is assembles using the disk-stacked method, where multiple oxygen-free copper components are stacked along the beam axis. The design incorporates the side-coupled (SC) structure and the re-entrant structure with an accelerating gap at the center of the cavity. Due to the complex shape and the large number of components, there are difficulties in manufacturing efficiency. On the other hand, the longitudinally-split method divides the structure along a plane including the beam axis, independent of the number of cells, typically into only two halves or four quadrants, which significantly reduces the number of components. Building on the development experience of the quadrant-type X-band accelerating structure in the CLIC project, we have been working on the development of a compact, high-gradient, high-shunt impedance, SC-type C-band accelerating structure based on this configuration. We had reported previous work, fabrication of the full-scale structure, low-power RF test result, and preliminary first beam acceleration test at an energy level limited by the testing facility. In this presentation, we will report the progress of our work, RF conditioning and a high-power beam test in the actual operating conditions.
Paper: TUP7627
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-TUP7627
About: Received: 08 May 2026 — Revised: 19 May 2026 — Accepted: 21 May 2026 — Issue date: 22 May 2026
TUP7629
Assessment of RF System Capability in the J-PARC Main Ring Toward 1.3 MW Operation
1845
The J-PARC Main Ring plans to increase its beam power from 830 kW to 1.3 MW for the Hyper-Kamiokande neutrino experiment by 2028. To enable this higher-power operation, the RF system has been upgraded by increasing both the number of cavities and the anode current of the tetrode tubes. However, the required anode current is now approaching the maximum capability of the tubes, and several associated power-supply systems are also nearing their operational limits. Traditionally, the anode current has been estimated using a phasor diagram approach. As an alternative, we evaluate the current using LTspice simulations, which can incorporate the vacuum-tube characteristics, cavity impedance, and beam loading. We have constructed an LTspice model of the Main Ring RF system that includes the impedance of the magnetic alloy loaded RF cavity, two 600 kW tetrode tubes, and the beam current corresponding to eight bunches with a total intensity of 3.3 \times 10^{14} protons. This allows us to estimate not only the anode current but also the screen grid currents, and the simulation results have been compared with measurements. In this paper, we present LTspice based RF system calculations for the Main Ring and evaluate the RF power requirements necessary to achieve 1.3 MW beam operation.
Paper: TUP7629
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-TUP7629
About: Received: 15 May 2026 — Revised: 21 May 2026 — Accepted: 21 May 2026 — Issue date: 22 May 2026
TUP7636
Performance and production status of the high-Q cryomodules for the SHINE project
1860
The SHINE Linac was optimized to accelerate the beam to 8 GeV with 54 high-Q cryomodules (CMs), benefiting from the higher performance of the cavities and CMs. Currently, the mass production of SHINE cavities and CMs is ongoing. Up to now, around 350 high-Q cavities with mid-T baking or N-doping recipes have been fabricated and tested. Most of them have been assembled in CMs. More than 30 CMs have been tested. In this paper, we report the performance of high-Q CMs and lessons learned during the production.
Paper: TUP7636
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-TUP7636
About: Received: 15 May 2026 — Revised: 16 May 2026 — Accepted: 16 May 2026 — Issue date: 22 May 2026
TUP7640
Design and vertical test of a passive 3rd harmonic superconducting cavity for HALF storage ring
1868
A 3rd harmonic superconducting (SC) cavity is being developed for lengthening bunch and improving beam lifetime in the Hefei Advanced Light Facility (HALF) storage ring. This SC cavity is excited by an electron beam with 350 mA current, 1 nC charge, and ~6.7 ps length and requires strong damping of higher-order-modes (HOMs) in order to meet beam instability requirements. This paper presents design and vertical test of this passive 3rd harmonic SC cavity in detail. The vertical test results indicate that the cavity accelerating voltage reaches as high as 1.5 MV with the quality factor better than 3.4E8 and there is no multipacting or field emission.
Paper: TUP7640
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-TUP7640
About: Received: 13 May 2026 — Revised: 16 May 2026 — Accepted: 17 May 2026 — Issue date: 22 May 2026
TUP7642
Entropy generation analysis of heat loads in an SSR2 superconducting cryomodule
1874
The SSR2 superconducting cryomodule is analyzed in terms of static and dynamic heat loads and the associated entropy rates at the 2 K stage. The reference cryomodule contains six superconducting single-spoke resonator cavities. Static heat loads arise from conduction through cryomodule supports, couplers, cables, and beam-pipe interfaces, and from radiation through the insulation vacuum. Dynamic heat load is produced by radio-frequency surface dissipation. At 2 K, static and dynamic heat loads of 20 W and 80 W correspond to entropy rates of 10 W/K and 40 W/K, respectively, for a total cold-stage entropy rate of 50 W/K. The dynamic contribution ac-counts for 80% of the total entropy rate and scales inversely with the intrinsic quality factor Q₀. A coefficient-of-performance analysis shows that 100 W at 2 K requires at least 14.9 kW in the Carnot limit and about 100 kW for a representative real COP of 0.001. The results show that reducing radio-frequency loss, increasing Q₀, minimizing static heat leakage, and improving refrigerator performance directly reduce entropy generation and improve cryomodule efficiency.
Paper: TUP7642
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-TUP7642
About: Received: 07 May 2026 — Revised: 11 May 2026 — Accepted: 16 May 2026 — Issue date: 22 May 2026
TUP7644
Development of a novel solid-state modulator and its application in high-power klystrons
1878
This paper presents a highly integrated solid-state modulator designed to drive high-power klystrons in linear accelerators. The modulator employs a vertically integrated architecture in which the solid-state module array is directly combined with the high-voltage pulse transformer. This configuration eliminates long high-voltage cable connections, reduces parasitic inductance, and improves compactness and maintainability. The proposed modulator has been experimentally validated in high-power tests with an 80 MW S-band klystron at the Hefei Advanced Light Facility (HALF), achieving the required pulse waveform quality and stability. In addition, with limited modification, the same architecture can be adapted to higher repetition-rate applications such as the Super Tau-Charm Facility (STCF) injector, demonstrating its scalability for future large-scale accelerator facilities.
Paper: TUP7644
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-TUP7644
About: Received: 15 Apr 2026 — Revised: 20 May 2026 — Accepted: 21 May 2026 — Issue date: 22 May 2026
TUP7653
Progress in the PM based LGBM magnets for K-4GSR
1888
A 4th generation storage ring based light source is being developed in Korea since 2021. It features <60 pm rad intrinsic beam emittance, about 800 m circumference, 4 GeV e-beam energy, full energy booster injection, and more than 40 beamlines which includes more than 24 insertion device (ID) beamlines. To optimize the beam emittances, longitudinal gradient bending magnet is applied in the storage ring design. To minimize the operation costs, and to save the lattice space, Sm2Co17 based Longitudinal Gradient Bending Magnet (LGBM) is being developed following ESRF-EBS, and HEPS. It has 5 steps of field level ranging from 0.75 T~0.15 T with approximately 2 m length. In this report, the compensation scheme of temperature dependence, and field tuning to meet the bending angle, and apex points will be described.
Paper: TUP7653
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-TUP7653
About: Received: 14 May 2026 — Revised: 18 May 2026 — Accepted: 21 May 2026 — Issue date: 22 May 2026
TUP7657
Design and construction of the twin-aperture superconducting quadrupole full-size prototype for the STFC IRSM
1901
Super Tau Charm Facility (STCF) is the third-generation e+-e- collider under design and R&D with a circumference of about 800-900 m, a center-of-mass energy range from 2-7 GeV and design luminosity higher than 0.5 x 1035 cm-2 s-1, about 100 times higher than BEPC-II. To squeeze the beam for higher luminosity, compact twin-aperture high gradient interaction region superconducting magnet (IRSM) systems are required on both sides of interaction point (IP). The IRSM system consists of four twin-aperture superconducting quadrupole magnets. As part of the key R&D activities at accelerator CDR stage, full-scale twin-aperture QD1 quadrupole magnets were designed and constructed. The QD1 magnets have design field gradients of 50 T/m, field harmonics below 0.2‰, and site at 900 mm distance away from IP at beam crossing angle of 60 mrad. In this paper, details of QD1 design, construction and test are reported.
Paper: TUP7657
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-TUP7657
About: Received: 15 May 2026 — Revised: 18 May 2026 — Accepted: 18 May 2026 — Issue date: 22 May 2026
TUP7666
Development of a Fast-feedback Deflector Magnet Power Supply for The Next Generation Heavy Ion Therapy
1916
Application of a 10 Hz fast-cycling induction synchrotron (IS) to the next generation of heavy ion therapy called Energy Sweep Compact Rapid Cycling Hadron Therapy (ESCORT), where the ion beam with energy sweeping is delivered tracking a tumor target in a deformed and moving organ and monitoring the irradiation dose profile in a real-time during irradiation, is under investigation* ** in the collaboration of KEK and SAMEER. To enable precise targeting, this power supply must allow the deflector magnet to shift the beam irradiation position accurately by varying the peak current value for each pulse with the excitation pattern of the main magnet system. This paper describes the initial experimental results obtained by combining a prototype power supply with a steering magnet.
Paper: TUP7666
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-TUP7666
About: Received: 11 May 2026 — Revised: 19 May 2026 — Accepted: 21 May 2026 — Issue date: 22 May 2026
TUP7668
Development of a Modular Magnet Power Supply with Parallel Operation for the Korea-4GSR Storage Ring
1920
The storage ring of the Korea-4GSR (Korea 4th Generation Synchrotron Radiation) facility currently under construction consists of a total of 1184 magnets, of which 792 are large-capacity magnets requiring rated currents of 140A or 280A. To drive these large-capacity magnets, magnet power supplies (MPSs) are required to support parallel operation in order to minimize the number of MPS types, thereby improving maintenance efficiency and reducing manufacturing costs. In addition, to ensure beam stability and low-emittance beam performance, current stability of less than 10 ppm and accuracy of less than 100 ppm under long-term operation are required during the prototype development. This paper presents a storage ring modular magnet power supply (SR Modular MPS) rated at 140A, which is designed in a modular form with master–slave-based parallel operation capability, allowing the rated output current to be expanded up to 280A through two-unit parallel operation. The proposed MPS can supply both 140A and 280A rated currents to large-capacity magnets using a single MPS type, and satisfies the MPS performance requirements over the entire operating range through a compensation method applied based on operating-condition-dependent characteristics. Experimental results demonstrate that the developed SR Modular MPS achieves a stability of 2.28 ppm and an accuracy of 45.79 ppm in single-unit operation, and a stability of 5.1 ppm and an accuracy of 45.88 ppm in parallel operation.
Paper: TUP7668
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-TUP7668
About: Received: 18 May 2026 — Revised: 18 May 2026 — Accepted: 21 May 2026 — Issue date: 22 May 2026
TUP7680
Investigation on the vacuum properties of Al-TiZrV bilayer films
1937
Maintaining an ultra-high vacuum (UHV) environment is essential for the Hefei Advanced Light Facility (HALF) to achieve its design performance. Owing to the dimensional limitations imposed by small-aperture vacuum chambers, non-evaporable getter (NEG) films are commonly applied to the inner walls to enhance vacuum performance. However, conventional NEG films increase the resistive-wall impedance of the vacuum pipes, there-by exacerbating the wakefield effects. To address this problem, a novel composite film, Al-TiZrV, has been developed. By covering the TiZrV film surface with a highly conductive film, it can reduce the resistivity of the composite film. The results show that while the addition of the Al layer reduces the resistivity significantly, it increases the secondary electron yield (SEY), exacerbating the electron cloud effect. This study provides insights into the complex properties of similar bilayer films for future research on accelerator-related materials.
Paper: TUP7680
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-TUP7680
About: Received: 15 Apr 2026 — Revised: 29 Apr 2026 — Accepted: 16 May 2026 — Issue date: 22 May 2026
TUP7684
Design of distributed pumping system using NEG strip for HALF
1946
The design of a distributed pumping system using NEG (Non-Evaporable Getter) strips for the slender beam pipes of the Hefei Advanced Light Fa-cility (HALF) is presented. To achieve a high pumping speed and pumping capacity in a limited pumping space, a NEG strip with distributed pumping capacity was considered. A prototype of HALF vacuum cham-ber, which can be inserted into NEG strip and matched with magnet system, is designed. The activation tem-perature of NEG strip and the ultimate vacuum after activation are tested, and the results are in good agreement with those obtained from the simulation.
Paper: TUP7684
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-TUP7684
About: Received: 16 Apr 2026 — Revised: 15 May 2026 — Accepted: 20 May 2026 — Issue date: 22 May 2026
TUP7687
Investigation of outgassing properties of CuZr and CuCrZr vacuum pipes
1949
The Hefei Advanced Light Facility (HALF) is the fourth-generation synchrotron radiation light source based on Diffraction-limited Storage Ring (DLSR) with low beam emittance, high brightness and coherent photon flux. According to the physical design re-quirements of the HALF, the vacuum chamber struc-tural materials should have low outgassing rate, good electrical and thermal conductivity, high strength, and non-magnetic. CuZr and CuCrZr were selected as structural materials for the HALF storage ring vacuum chamber structural materials, taking into account ma-terial properties and manufacturing process. In this paper, thermal outgassing performances of CuZr and CuCrZr alloy pipes under temperature rise was inves-tigated for the design and calculation of HALF vacuum systems.
Paper: TUP7687
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-TUP7687
About: Received: 16 Apr 2026 — Revised: 18 May 2026 — Accepted: 20 May 2026 — Issue date: 22 May 2026
TUP7694
Study of the Emissivity of Copper Oxide Thin Films by Cylindrical Magnetron Sputtering
1963
High-energy electron beams operating in accelerator vacuum chambers can easily cause heat accumulation on the surfaces of in-vacuum components. When convective cooling and effective conductive heat dissipation are limited, the thermal radiation capability of material surfaces becomes an important heat dissipation mechanism. In this study, copper oxide (CuO) thin films were deposited on Oxygen-Free Copper (OFC) substrates to investigate their enhancement of surface thermal radiation char-acteristics. Experimental results show that the prepared CuO films exhibit dense columnar grain structures with a monoclinic CuO (002) preferred orientation. Emissivity measurements indicate that the average high-temperature emissivity of bare OFC substrates is approximately 0.1, while CuO-coated samples can achieve values up to 0.52, demonstrating improved infrared thermal radiation performance. The coating system setup, experimental procedures, and emissivity measurement methods will be fur-ther described in this paper.
Paper: TUP7694
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-TUP7694
About: Received: 13 May 2026 — Revised: 19 May 2026 — Accepted: 21 May 2026 — Issue date: 22 May 2026
TUP7715
Mechanical design and structural analysis of septum magnet for Thailand new synchrotron light source (SPS-II)
2000
The Synchrotron Light Research Institute of Thailand is developing a new eddy-current septum magnet as part of the pulsed magnet systems for its next-generation synchrotron light source, the Siam Photon Source II (SPS-II). This work focuses on mechanical design and structural analysis of the septum magnet to improve the prediction of anomalies and potential failures over the machine's operational lifetime. Finite element method is used to evaluate both static deformation of the in-air magnet yoke and transient vibration response of the septum blade under pulsed magnetic force, which can induce fatigue damage through cumulative stress cycles. Static analysis indicates that the proposed design satisfies structural integrity and magnetic field uniformity requirements. The impulse vibration fatigue assessment of the septum blade falls within the ultra-high-cycle fatigue (UHCF) regime, with stablished S-N data for copper alloys providing design guidance for extending the magnet's operational life.
Paper: TUP7715
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-TUP7715
About: Received: 16 May 2026 — Revised: 22 May 2026 — Issue date: 22 May 2026
TUP7722
High-Precision PCB-Based Rotating Coil System for Multipole Magnet Measurements in the 4GSR Storage Ring
2011
For the reduction of beam emittance in a Korea-4GSR project, the storage ring will be equipped with 344 quadrupole, 168 sextupole, and 56 octupole magnets. These multipole magnets require precise magnetic measurements to verify not only the field strength but also harmonic components within the specified tolerances over a good field region with a diameter of 30 mm. To meet this requirement, a PCB-based rotating coil measurement system has been developed. The PCB consists of a 14-layer multilayer structure incorporating both main and bucking coils, enabling high-precision measurement of allowed and higher-order harmonic components. The PCB length was designed to be 660 mm, considering to the effective magnetic length of the 4GSR multipole magnets. To minimize mechanical sag, the rotating shaft was fabricated from ceramic material and positioned at the magnetic field center using a high-precision XY stage with 0.1 μm resolution. The developed rotating coil system achieves a measurement precision better than 5 × 10-4, demonstrating its suitability for high-accuracy characterization of small-aperture multipole magnets in the 4GSR project.
Paper: TUP7722
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-TUP7722
About: Received: 17 May 2026 — Revised: 18 May 2026 — Accepted: 21 May 2026 — Issue date: 22 May 2026
TUP7723
Construction of Permanent Magnet Arrays without Custom Materials
2014
Permanent magnet Halbach arrays can be used for beam steering and focusing for synchrotron light sources, Fixed Field Accelerators, and plasma accelerators. Conventional implementations require many custom wedge-shaped magnets with tailored geometries and magnetisation angles, preventing material reuse. We present a method for constructing Halbach arrays from many identical rectangular magnets, each rotated in the transverse plane to approximate the optimal configuration. Although this introduces gaps and reduces magnetic efficiency compared with custom-wedge designs, it simplifies fabrication, lowers costs, and enables the magnets to be redeployed for future applications. A prototype array based on this approach has been built for Project TURBO at the University of Melbourne, and measurements confirm that the magnetic field quality meets the requirements of the planned beamline. Construction of the full arrays for TURBO will soon commence, and the reusability of the magnets is expected to provide long term flexibility for subsequent accelerator projects.
Paper: TUP7723
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-TUP7723
About: Received: 13 May 2026 — Revised: 18 May 2026 — Accepted: 21 May 2026 — Issue date: 22 May 2026
TUP7901
R&D on efficient ultra-high frequency RFQ structures
2035
RFQ (Radio frequency quadrupole) accelerating structures for RF frequencies lower than 400 MHz have been intensively investigated for decades. To realize modern medical accelerators with more compact layouts, there is an increasing interest to use ultra-high frequencies (UHF: 0.3 - 3 GHz). This study performs R&D towards efficient UHF RFQ structures. The design and simulation results will be presented.
Paper: TUP7901
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-TUP7901
About: Received: 13 May 2026 — Revised: 20 May 2026 — Accepted: 21 May 2026 — Issue date: 22 May 2026
TUP8002
Compact X-Band Linear Accelerators Design for On-Site Industrial Applications
2039
The progressive replacement of radioactive sources is stimulating growing interest in compact linear accelerators, which are better suited for field deployment. Such systems must emphasize modularity, transportability, and, above all, reliable performance under operational conditions. This work introduces a family of compact X-band linear accelerators designed to produce electron beams in the low-MeV energy. The engineering design focuses on the key component: the accelerator structure. A biperiodic on-axis coupled standing-wave structure was selected, operating in $\pi/2$ mode. Simulation results demonstrate that the proposed configurations achieve the targeted energy levels with controlled beam transmission, while providing a focal spot size (FWHM) below 1 mm, significantly outperforming conventional radioactive sources ($\approx 5$ mm). This paper summarizes the overall design approach, highlights the main simulation results, and outlines the current progress of development activities.
Paper: TUP8002
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-TUP8002
About: Received: 15 Apr 2026 — Revised: 15 May 2026 — Accepted: 17 May 2026 — Issue date: 22 May 2026
TUP8004
Measured properties of the mixed helium and carbon ion beam at MedAustron
2042
The implementation of a sequential injection scheme for mixing helium and carbon ions from different ion sources at the MedAustron accelerator facility enabled the first successful delivery of a mixed helium and carbon ion beam in a synchrotron therapy facility. Precise knowledge of both the helium and the carbon properties is an essential input for designing treatment monitoring experiments, however, it is not trivial to distinguish the helium and carbon beam properties within the mixed beam. This contribution discusses the acquired beam properties delivered to the first treatment monitoring research experiments at MedAustron since late 2025. Most notably, the measurements demonstrate that beam compositions with 0-100 % helium content can be achieved. The mixed beam generation at MedAustron is still in an early stage, which is reflected in significant shot-to-shot fluctuations in the beam intensity and composition as well as differences in the transverse beam sizes of the extracted helium and carbon ions.
Paper: TUP8004
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-TUP8004
About: Received: 13 May 2026 — Revised: 17 May 2026 — Accepted: 17 May 2026 — Issue date: 22 May 2026
TUP8008
Ultra-high dose-rate irradiation experiments at FLUTE
2049
The linac-based test facility FLUTE at the Karlsruhe Institute of Technology (KIT) can be operated with a wide range of beam parameters, such as bunch charge, bunch length and repetition rate. This flexibility makes FLUTE an interesting test-bed for studies of accelerator-based ultra-high dose-rate irradiation with electron beams. Based on the time structure of the produced electron pulses, the instantaneous dose-rate can be tuned to exceed $10^{11}$ Gy/s with an average dose rate exceeding 40 Gy/s. At the same time, FLUTE can also provide average dose-rates closer to conventional rates in the order of 0.1 Gy/s.
Paper: TUP8008
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-TUP8008
About: Received: 11 May 2026 — Revised: 17 May 2026 — Accepted: 22 May 2026 — Issue date: 22 May 2026
TUP8009
Advancements and dosimetry of a single-turn extraction for FLASH radiotherapy studies at ELSA
2053
Ultra-high-energy electrons are used to investigate their effects on cell samples in nanosecond to microsecond pulses at the electron accelerator facility ELSA. This may allow highly efficient treatment of deep-seated tumors through the FLASH effect. Previous studies at ELSA using an inital extraction mode with 250 ns long pulses from the 1.2 GeV booster synchrotron demonstrated the suitability for FLASH radiotherapy studies. A newly developed single-turn extraction scheme from the stretcher ring now enables access to beam energies of up to 3.2 GeV with pulse lengths of approximately 330 ns and improved beam stability. In preparation for upcoming cell irradiation studies with this new extraction mode, precise dose determination is carried out by combining radiochromic film measurements with Geant4 simulations over the full energy range from 1.2 GeV to 3.2 GeV. Depth-dose curves from the previous and current operation modes are compared. Additionally, studies of Cherenkov radiation are performed to evaluate its potential for beam characterization.
Paper: TUP8009
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-TUP8009
About: Received: 12 May 2026 — Revised: 17 May 2026 — Accepted: 17 May 2026 — Issue date: 22 May 2026
TUP8013
Evaluation of orbit correction methods for the Helium Light Ion Compact Synchrotron HeLICS
2056
Within the framework of the Next Ion Medical Machine Study (NIMMS) collaboration at CERN, closed orbit correction schemes are developed for the Helium Light Ion Compact Synchrotron (HeLICS) - a novel synchrotron design in development for cancer treatment. Different options for closed orbit correction are presented, including the possibility of applying beam-based quadrupole alignment without dedicated corrector magnets. The limitations and advantages of the different closed orbit correction methods are evaluated against each other in order to determine the best scheme for HeLICS.
Paper: TUP8013
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-TUP8013
About: Received: 17 Apr 2026 — Revised: 19 May 2026 — Accepted: 22 May 2026 — Issue date: 22 May 2026
TUP8014
ATSOA at CERN: A Hands On Accelerator Course in the EURO-LABS Framework
2060
Beyond providing Transnational Access to major Research Infrastructures (RIs) across Europe, the European Laboratories for Accelerator Sciences (EURO-LABS) programme supports advanced training activities. Within this framework, an Advanced Training School on the Operation of Accelerators (ATSOA) is organised at CERN. The school targets students, young researchers, and professionals in the field of accelerator science, offering them a unique opportunity to participate in a week of hands-on training. Five CERN facilities — CLEAR, AD/ELENA, ISOLDE, PSB and LEIR — are involved in the training, allowing participants to familiarise themselves with different accelerator types and particle species. Under the guidance of experienced instructors, they carry out dedicated experiments designed to illustrate key physics concepts and operational principles that can be applied in their own work. This contribution gives an overview of the past schools and an outlook for future courses.
Paper: TUP8014
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-TUP8014
About: Received: 13 May 2026 — Revised: 19 May 2026 — Accepted: 22 May 2026 — Issue date: 22 May 2026
TUP8018
A Status update of LhARA, an Accelerator-driven Radiobiology Research Initiative
2068
LhARA is multidisciplinary collaboration that is embarking on an initiative to use laser-driven ions in a hybrid acceleration scheme with a fixed-field alternating gradient (FFA) accelerator to deliver a systematic radiation biology programme and lay the technological foundations for the transformation of proton and ion beam therapy. LhARA is in an R&D phase of activity that is overseeing the development of a number of accelerator technologies to support our initiative, as well as conducting experiments in the Proof-of-Principle for LhARA and Radiobiology (PoPLaR) programme that is examining the effect of laser-driven ions on biological tissue samples. Here, we present a summary of the most recent updates from the LhARA collaboration, including Gabor plasma lenses for beam capture and focusing, magnetic beam delivery schemes for variably-sized, transversely uniform beam profiles, the FFA in LhARA’s second stage to reach clinically relevant ion energies, and an overview of the PoPLaR experiment.
Paper: TUP8018
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-TUP8018
About: Received: 13 May 2026 — Revised: 20 May 2026 — Accepted: 22 May 2026 — Issue date: 22 May 2026
TUP8029
The TIARA Collaboration: Shaping Two Decades of EU Support for Coordinated Accelerator R&D
2076
European accelerator research involves more than 150 institutions –research and technology infrastructures, universities and industry– meaning that impactful R&D requires large, well-structured collaborations among all innovation actors. The European Commission’s framework programmes can play a strategic role in enabling these collaborations, but their effectiveness depends on coherent organisation at the community level. Established in 2002 as ESGARD, the TIARA (Test Infrastructure and Accelerator Research Area) collaboration was created to promote and coordinate participation in EC calls. Its first major R&D project, CARE, began in 2004, followed by EuCARD, EuCARD2 and ARIES, and later by the innovation oriented I.FAST (2021-25). In parallel, TIARA supported 17 other projects, including design studies for new infrastructures and ESFRI-linked initiatives, securing €130 million in EC funding over 21 years, complemented by more than €200 million from partners. This paper outlines TIARA’s vision to promote multi-platform collaborative accelerator R&D, broaden the impact of the European accelerator science and technology, and plans to strengthen its role within future EC programmes.
Paper: TUP8029
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-TUP8029
About: Received: 30 Apr 2026 — Revised: 18 May 2026 — Accepted: 22 May 2026 — Issue date: 22 May 2026
TUP8031
Joint Development of Superferric Corrector Magnets for HL-LHC
2079
The HL-LHC project is a major upgrade of CERN’s LHC, aiming to enhance the collider’s integrated luminosity by a factor ten within ten operational years. Endorsed as top priority for the European Strategy for Particle Physics in 2013, the project was formally approved by CERN’s Council in 2015. To achieve its performance goal, HL-LHC relies on several technology drivers. Among the new magnets for the interaction regions, the superferric – named so, because they combine superconducting NbTi coils with iron pole pieces to enhance the magnetic field near the aperture – high-order mode correctors are key in ensuring beam quality and stability, correcting field errors and compensating non-linearities in the magnet lattice. These magnets were the object of a collaboration between CERN and INFN-LASA Milan, first joint project to deliver its full scope to HL-LHC. INFN-LASA was tasked with design, prototyping, and industrialization. Key to the delivery of 54 correctors by 2023 was the early initiation via the INFN MAGIX project, followed by two agreements for prototyping and series production. The collaboration spanned over a decade and benefited from the early involvement of the industrial partner SAES-RIAL. The paper reviews the collaboration, detailing cost structure, schedule adherence, and industrialization process. Focus is on key factors that contributed to the success of the collaboration and lessons applicable to large-scale partnerships for future accelerator projects.
Paper: TUP8031
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-TUP8031
About: Received: 12 May 2026 — Revised: 17 May 2026 — Accepted: 17 May 2026 — Issue date: 22 May 2026
TUP8032
Towards a Community of Practice in Project Management of Particle Accelerator and Big-Science Projects: The AcceleratePM Initiative
2083
Across Europe, several large-scale particle accelerator and big-science projects — each exceeding hundreds of millions of euros and extending over a decade — are under design or construction, with comparable initiatives underway in the US and China. Despite remarkable scientific achievements, many of them face cost and schedule drift, even when scientific performance targets haven’t been scaled down to maintain cost and timeline. Managing these complex, R&D-driven scientific facility projects requires approaches distinct from even the largest conventional infrastructure undertakings. Recognizing this need, a group of project management (PM) professionals active in particle accelerator initiatives has launched AcceleratePM*, the first international workshop dedicated to PM for accelerator and big-science projects. The first workshop, to be held at CERN in January 2026, will gather all major laboratories and projects to exchange methods, identify common challenges, and define best practices. This contribution presents the workshop scheme, themes, key-findings and planned outcomes, showcasing the largest recent projects – amongst which HL-LHC, ESS, FAIR, F4E – and aiming at informing the management of next-generation initiatives such as the Future Circular Collider (FCC). By building on common issues and most effective solutions, AcceleratePM intends to establish a lasting community of practice, shaping how large scientific projects are conceived, planned, and delivered.
Paper: TUP8032
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-TUP8032
About: Received: 12 May 2026 — Revised: 19 May 2026 — Accepted: 21 May 2026 — Issue date: 22 May 2026
TUP8035
accelECR: the Early Career Researcher network in Accelerator Science and Technology
2090
Early-career researchers (ECRs) are central to the advancement of accelerator science and technology, contributing across all areas - from R\&D, theory, and design to experiment, commissioning, and operation - at all scales, from small medical accelerators to large colliders. While accelerator projects are often high-cost, long-timescale, and resource-intensive, ECR perspectives are underrepresented in strategic planning and decision-making. Following the example of particle physics (ECFA ECR) and nuclear physics (NuFFER), the accelerator science and technology community now has its own ECR network: accelECR. Through regular seminars and community-driven events,accelECR fosters knowledge exchange, promotes inclusivity, and improves skill transferability across the field. It also serves as a collective platform through which accelerator ECRs can engage with high-level strategy and decision-making in the field. The motivation, organization, and framework of accelECR are presented in this contribution.
Paper: TUP8035
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-TUP8035
About: Received: 13 May 2026 — Revised: 19 May 2026 — Accepted: 22 May 2026 — Issue date: 22 May 2026
TUP8037
TEST OF C-BAND ELECTRON LINAC FOR FLASH RADIOTHERAPY
2094
Delivered at Ultra-High Dose Rates (UHDR), in the so-called FLASH regime, electron irradiation has shown the remarkable ability to spare healthy tissues while preserving tumor control, opening new perspectives for next-generation cancer treatments. The advancement of high-gradient accelerating structures has enabled the development of compact and cost-effective linear accelerators suitable for clinical environments. Within this framework, we present the electromagnetic design and testing results of the C-band RF prototypes for a 24 MeV Linac being installed at Sapienza University. The linac is composed of a standing-wave and a traveling-wave section. The standing-wave structure has been designed, manufactured, and tuned in collaboration with SIT Company, while the traveling-wave structure has been entirely developed in-house, including full fabrication and tuning, in collaboration with INFN. These prototypes represent a key step toward the realization of an advanced FLASH VHEE source for future clinical applications.
Paper: TUP8037
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-TUP8037
About: Received: 18 May 2026 — Revised: 21 May 2026 — Accepted: 22 May 2026 — Issue date: 22 May 2026
TUP8304
Integrated Sustainment Strategy through a Unified Accelerator Systems Definition
2097
The sustained reliability and availability of the LANSCE accelerator depend on a clearly defined and integrated “systems” framework. This foundation links five core sustainment strategies: Asset Management, Risk Management, Conduct of Engineering, Training & Qualification, and Data Collection & Analysis. Unifying these under a common structure enables consistent decision-making, coordinated resource use, prioritized maintenance, and system-level performance tracking. It breaks down silos, improves efficiency, and supports targeted workforce development while reinforcing clarity in roles, responsibilities, authority, and accountability. Realizing this vision requires deliberate planning, early stakeholder engagement, and a robust change management strategy to navigate organizational and cultural shifts. This unified framework bridges short-term needs with long-term goals, positioning LANSCE to sustain mission-critical operations through 2050 and beyond. The paper explores this integrated approach as a scalable model for other aging accelerator facilities seeking sustainment without compromising mission continuity.
Paper: TUP8304
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-TUP8304
About: Received: 04 May 2026 — Revised: 19 May 2026 — Accepted: 22 May 2026 — Issue date: 22 May 2026
TUV3301
Developing a Hybrid Accelerating Structure Based on Short-Pulse Structure Wakefield Acceleration
2107
Structure Wakefield Acceleration (SWFA) powered by ultra-short RF pulses (~10 ns) generated by Two-Beam Acceleration (TBA) at the Argonne Wakefield Accelerator (AWA) has demonstrated effective suppression of RF breakdowns and achieved gradients exceeding 400 MV/m at X-band frequencies. To fully exploit the benefits of this short RF pulse operation, an accelerating structure must simultaneously achieve two goals: high group velocity (Vg) to ensure rapid RF filling (need for high efficiency), and simultaneously maintain high shunt impedance (R) (need for high accelerating gradient). Conventional accelerating structures involve inherent tradeoffs between these parameters, limiting their effectiveness in the short-pulse regime. To this end, we developed a hybrid structure composed of two co-optimized sub-structures fed by one coupler at the middle: one backward wave (BW) filling and one forward wave (FW) filling sub-sections. This design not only preserves the short-pulse advantage but also amplifies the beam’s energy gain by effectively doubling the acceleration length without requiring extended RF pulse duration. In this work, we present the full RF design, wavefield and transient analysis, and beam-dynamics optimization for high-brightness operation, demonstrating the performance and feasibility of this novel short-pulse BTW–FTW accelerating concept.
Paper: TUV3301
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-TUV3301
About: Received: 14 May 2026 — Revised: 21 May 2026 — Accepted: 22 May 2026 — Issue date: 22 May 2026
TUV7601
High Reliability Digital Control Magnet Power Supply System for SPring-8-II
2115
We have developed new magnet power supply (PS) system for the forthcoming green light source facility, SPring-8-II. Aiming at highly reliable and energy conscious accelerator operations, various PSs with a variety of output current and voltage settings are designed such that (i) each PS with an output current larger than 250 A includes Silicon Carbide switching devices, achieving a conversion efficiency larger than 93% (ii) all PS are embedded with a full digital control system that enables a versatile individual parameter setting, and (iii) main PSs are connected in series to multipole magnets for suppressing PS failures as low as possible. For an individual current setting for the correction of betatron beatings and other purposes, we will prepare auxiliary PSs to add to each individual magnet where it is required. Bipolar PSs for steering magnets have been designed to provide stable output over the whole current range by optimizing our pulse width modulation control. Additionally, we have proposed a new option to adjust an individual current setting by implementing shunt resistors, and also a fast PS switcher that can quickly replace a failed PS with a backup PS without a beam loss is being prepared. We will present these new PS designs and the results of our demonstrations.
Paper: TUV7601
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-TUV7601
About: Received: 13 May 2026 — Revised: 20 May 2026 — Accepted: 21 May 2026 — Issue date: 22 May 2026
TUV8001
Commercial Accelerators for Proton Therapy - An Overview
2121
There are different accelerator types used for proton therapy of diverse tumours. In use are mostly classical cyclotrons, synchrocyclotrons and synchrotrons. In addition, linear accelerators were or are under development. This paper will give an overview on commercially available systems. Not only technical aspects are discussed, but also new developments in treatment methods like ARC and FLASH therapy as well as irradiations in upright position and the backlash on the used accelerator types. Furthermore practical issues like certification and embedding those systems in a hospital environment will be described and evaluated.
Paper: TUV8001
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-TUV8001
About: Received: 13 May 2026 — Revised: 20 May 2026 — Issue date: 22 May 2026
TUV8003
CERN Innovation Programme on Environmental Applications (CIPEA): leveraging accelerator technologies for environmental impact
2126
The CERN Innovation Programme on Environmental Applications (CIPEA) was launched in 2022 as a call for ideas to stimulate novel environmental applications based on CERN’s technologies, scientific expertise and unique research infrastructure. CIPEA has since evolved into an integrated framework encompassing many CERN initiatives aimed at generating environmental impact beyond the Organization’s own operational footprint. More than 25 projects are currently being developed with external partners, primarily from industry, drawing on competences integral to accelerator science, including superconductivity, high-field magnets, materials, cryogenics, vacuum systems, radiofrequency technologies, cooling and ventilation, and laser beams. Activities are structured around four key application areas: renewable and low-carbon energy; clean transportation and future mobility; climate-change mitigation and pollution control; and sustainability and green science. CIPEA is largely externally funded, with over 80% of its resources contributed by partner organizations. This paper outlines the programme’s overall strategy, describes the priority development axes within each application area, provides an overview of ongoing efforts and highlights selected flagship projects that exemplify CIPEA’s innovation potential.
Paper: TUV8003
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-TUV8003
About: Received: 13 May 2026 — Revised: 19 May 2026 — Accepted: 21 May 2026 — Issue date: 22 May 2026
WEO4M02
Beam tests of a permanent magnet medical accelerator arc from 10-250MeV
2148
The FLASH hadron therapy accelerator proposed by Trbojevic uses permanent magnets with nonlinear fields to allow rapid cycling from 10 to 250MeV while keeping the ring tune constant. A test beamline of four cells from this ring (22.5 degree angle) was built at BNL and tested at the NSRL facility with protons and at the Tandem Van de Graaff with deuterons. The magnets consist of 24 neodymium-iron-boron (NdFeB) wedges magnetised in different directions and arranged to produce the required nonlinear field profile across the oval aperture for the beam movement, with fields of up to 1.85 Tesla. Beams were transmitted at all rigidities tested over a 5.3x momentum ratio, with output location moving systematically with energy as required.
Paper: WEO4M02
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEO4M02
About: Received: 14 Apr 2026 — Revised: 12 May 2026 — Accepted: 15 May 2026 — Issue date: 22 May 2026
WEO3T03
A Portable Muon Source for artificial muon muography
2158
Muography is a useful technology for non-destructive inspection of a large-scale structure. Muography with cosmic ray muons has limitations such as low rates, particularly low muon rates in the horizontal direction, and energy spreading, which require long observation times and limit its resolution. Worldwide, large structures such as bridges built during the economic development period of the 1950s-1960s have reached the end of their useful life, and the principle of preventive maintenance is being applied to save the resources, by understanding their interiors and renewing them with priority given to structures that have deteriorated. At this time, a technology of non-destructive inspection applicable to such large structures is required, and Muography using a portable artificial muons source is a promising candidate for this purpose. In this presentation, the results of the investigation of the portable artificial muon source will be presented.
Paper: WEO3T03
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEO3T03
About: Received: 16 Apr 2026 — Revised: 19 May 2026 — Accepted: 20 May 2026 — Issue date: 22 May 2026
WEO3T04
Progress Towards High-Repetition-Rate Plasma Wakefield Acceleration at FLASHForward
2163
Radiofrequency linacs accelerate thousands of bunches per second, which should be matched by beam-driven plasma wakefield accelerators (PWFAs) if their benefits as high-acceleration-gradient energy boosters are to be fully exploited. However, demonstrations to date have accelerated only ~10 bunches per second. At FLASHForward, key issues are being solved to bridge this gap. Analytic models have been developed to show how to generate bunch pairs from the photocathode with the longitudinal shape optimised for plasma acceleration, thus reducing stray radiation compared to a collimator system. To deal with large energy depositions from rapid plasma creation and acceleration events benchmarked models have been built to determine the heating of the plasma source at kHz repetition rates, so that remedial measures can be developed. Furthermore, we have seen that ionisation induced by the wakefield-perturbed plasma can limit the maximum repetition rate. Finally, PWFAs must produce large energy gains for photon science or particle physics applications. We recently demonstrated acceleration of bunches from 1.2 to > 1.7 GeV over 0.5 m of plasma, with < 2% energy spread.
Paper: WEO3T04
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEO3T04
About: Received: 01 Apr 2026 — Revised: 21 May 2026 — Issue date: 22 May 2026
WEI5M03
Realization of high-intensity beams with smaller emittance without a transverse feedback system
2176
The RCS at J-PARC is a kicker-impedance-dominant machine, which exceeds the impedance budget from a classical viewpoint. However, we have achieved a 1-MW beam without any transverse feedback by fully utilizing the indirect space charge effect to suppress beam instabilities. Although the indirect space charge effect is beneficial, the beam instability can still occur in a high-intensity beam with a smaller transverse emittance. To address this, we installed diode stacks and resistors at the ends of the four kicker power cables and have successfully conducted routine operations. This approach theoretically opens the door to achieving high-quality, higher-intensity beams, including a 2-MW beam, as no transverse feedback is required.
Paper: WEI5M03
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEI5M03
About: Received: 15 Apr 2026 — Revised: 04 May 2026 — Accepted: 19 May 2026 — Issue date: 22 May 2026
WEO6M01
AI and machine learning techniques for LNL accelerators
2193
The application of Artificial Intelligence (AI) and Machine Learning (ML) to particle accelerator systems has emerged as an effective strategy for managing complex operations and enhancing performance. At INFN-Legnaro National Laboratories (INFN-LNL), both offline and online AI/ML-driven approaches have been developed to improve beam dynamics, reduce setup times, and increase overall accelerator efficiency. Offline efforts focus on surrogate modeling of complex facilities such as ANTHEM BNCT, as well as on virtual diagnostics implemented using supervised neural operators. By combining these tools with AI/ML optimization algorithms, new design and commissioning strategies are being explored to further enhance beam quality and operational performance. In parallel, online real-time optimization strategies based on Bayesian Optimization (BO) has delivered promising results. Notably, at the PIAVE-ALPI superconducting accelerator, the application of BO improved beam transmission up to 85%, a significant increase compared to the typical operational average of 35%. These advances demonstrate the growing impact and future potential of AI/ML technologies in accelerator science and operations.
Paper: WEO6M01
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEO6M01
About: Received: 11 May 2026 — Revised: 18 May 2026 — Accepted: 21 May 2026 — Issue date: 22 May 2026
WEP1016
UPDATE ON THE ITN COORDINATED EFFORT FOR ILC TECHNOLOGY DEVELOPMENT IN EUROPE
2231
The ITN-EU consortium, coordinated by CERN with the support of CEA-Saclay and INFN-LASA, is advancing Europe’s contribution to the International Linear Collider (ILC) through the development and validation of high-performance superconducting radiofrequency (SRF) cavities. Activities focus on establishing an optimized production chain, from single-cell R&D to the industrialization of 9-cell cavities. Material procurement and quality control have been completed, and prototype single cells are fabricated and they will be used to assess advanced surface treatment strategies. EU partners are also preparing technical specifications and harmonizing production with Japanese High Pressure Gas Safety requirements. Europe will provide two fully prepared 9-cell cavities for installation in an ILC-type cryomodule assembled and tested at KEK, demonstrating Europe’s integrated and strategic role in the global SRF program.
Paper: WEP1016
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEP1016
About: Received: 14 May 2026 — Revised: 18 May 2026 — Accepted: 18 May 2026 — Issue date: 22 May 2026
WEP1304
Injecting and Ramping Trapped Beam in Hadron Accelerator
2247
In developing an alternative method of jumping transition in the Electron Ion Collider Hadron Storage Ring, simulations have been performed to show feasibility. Many challenges occur while ramping trapped beam. The effect of snapback on the superconducting magnets, longitudinal oscillations, and evolution of the island tune will be presented.
Paper: WEP1304
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEP1304
About: Received: 15 May 2026 — Revised: 18 May 2026 — Accepted: 21 May 2026 — Issue date: 22 May 2026
WEP1307
Hadron Storage Ring Spin Rotators & Spin Tune Compensation
2251
The Electron Ion Collider (EIC) calls for collisions of longitudinally polarized protons and helium-3 on electrons. The polarized hadron beams will be accel- erated and stored in the Hadron Storage Ring (HSR). To achieve longitudinal polarization at the interaction point (IP), spin rotators are placed on either side of the IP at 35.28 and -61.35 mrad. Due to the asymmetry of the rotators, their ramping and use will result in a shift of νs from 1/2. The HSR has six snakes that can be used to compensate for the ∆νs. The planned storage energies for protons are 41, 100, and 275 GeV, and for helium-3 are 41, 100, and 183 GeV/u. The updated rotator currents at each of these energies is provided, in addition to the ∆νs and the compensation requirements of the snakes.
Paper: WEP1307
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEP1307
About: Received: 12 May 2026 — Revised: 18 May 2026 — Accepted: 21 May 2026 — Issue date: 22 May 2026
WEP1318
Progress of the RF Systems for the Electron-Ion Collider
2269
The Electron-Ion Collider (EIC) under construction at Brookhaven National Laboratory (BNL) is being developed in partnership with DOE’s Thomas Jefferson National Accelerator Facility. The EIC will deliver high-luminosity, variable center-of-mass energy collisions of highly polarized electron beams with highly polarized proton beams and ion beams. RF Systems for the EIC provide a variety of functions and operate across a wide range of frequencies, utilizing multiple cavity types. This talk will discuss the challenges and proposed solutions for the EIC RF systems, review the progress, and overview our plans for the RF Systems of the Accelerator Storage Rings.
Paper: WEP1318
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEP1318
About: Received: 13 May 2026 — Revised: 20 May 2026 — Accepted: 21 May 2026 — Issue date: 22 May 2026
WEP1333
Nickl-Zinc Ferrite Fast Tuner of 24.6 MHz Accelerating Cavity for Transition Crossing
2291
Ferrite fast tuner enables accelerating voltage phase modulation in sub-millisecond during the gamma jump coordinating with magnet lattice to keep longitudinal stability of the beam. Due to the three times higher beam current in hardon storage ring (HSR) of Electron-Ion Collider (EIC) than that in RHIC, the beam loading induced frequency detuning will be also multiplied. Hence a higher performance of the fast tuner is required for 24.6 MHz accelerating cavity in EIC. The existing ferrite tuner in 28 MHz cavity in RHIC has a tuning range of 4 kHz with DC bias from 5 to 55 Amps and power dissipation up to 2 kW. To improve this ferrite tuner design for 24.6 MHz cavity, we characterized the permeability and hysteresis loops of the M4C21 Nickl-Zinc ferrite toroid with and without DC current bias. A full RF simulation of the cavity coupled with the tuner was performed. The equivalent circuit models and transmission line theory are applied to interpret and improved the frequency tuning range and power dissipation.
Paper: WEP1333
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEP1333
About: Received: 15 May 2026 — Revised: 18 May 2026 — Accepted: 21 May 2026 — Issue date: 22 May 2026
WEP1340
Orbit Correction Studies on The Electron Transport Line from RCS to ESR
2295
A dedicated electron transfer line from Rapid Cycling Synchrotron (RCS) to Electron Storage Ring (ESR), referred to as the RTE line has been designed for the Electron-Ion Collider (EIC). The beamline follows a straight-line geometry, with a length of 133 m, and is consists with two matching sections and a FODO section for beam diagnostics. Imperfections with magnet alignments introduce orbit distortions, making orbit correction scheme a critical component in the design. To facilitate orbit correction, each quadrupole magnet is equipped with a pair of beam position monitors (BPMs) and kickers. The Singular Value Decomposition (SVD) algorithm is used for orbit correction and tolerance studies. This paper presents the ongoing progress in the optics design and error correction scheme of the RTE line.
Paper: WEP1340
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEP1340
About: Received: 13 May 2026 — Revised: 19 May 2026 — Accepted: 21 May 2026 — Issue date: 22 May 2026
WEP1342
Damping Higher Order Modes for the Cool Copper Collider
2299
For next generation particle collider designs, such as the Cool Copper Collider, small beam sizes, short bunch spacing, and beam stability are required to reach the luminosities desired to search for new physics. One challenge to overcome is damping the excitation of higher order modes in accelerating cavities. These modes are excited by wakefields induced by the beam, and must be removed before they are seen by the following bunch to prevent deflecting kicks that will spoil beam stability. The solution is the addition of damping slots on the accelerator cavities that can couple to these higher order modes and remove them from the central part of the cavity that the beam passes through, to reduce the kick factor of the mode. Additionally, these damping slots can lower the Q value for these modes, causing the excitation to die out between bunches because the mode cannot resonate in the cavity for as long. In this study, we optimize the damping slot geometry to remove higher order modes from the accelerating cavity while preserving the fundamental accelerating mode.
Paper: WEP1342
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEP1342
About: Received: 13 May 2026 — Revised: 20 May 2026 — Accepted: 21 May 2026 — Issue date: 22 May 2026
WEP1354
Preinjector Design Update for the EIC
2322
To mitigate beam instabilities associated with low magnetic fields, the Rapid Cycling Synchrotron (RCS) for EIC has been redesigned to operate with a higher injection energy of 750 MeV, accepting only one bunch at a time and accelerating it immediately to collision energy. As a result, the electron pre-injector must also be updated to supply an appropriately matched beam. In the latest pre-injector concept, the extraction energy has been increased to meet the new RCS requirement, and a dedicated Beam Accumulator Ring (BAR) has been added to provide the required bunch merging. To maintain comparable cost while meeting performance goals, the pre-injector design adopts Wien filters for spin rotation, an L-band capture linac to preserve polarization, a reduced bunch charge that eliminates the need for a stretch section, and a high-gradient S-band linac. This proceeding presents the updated EIC pre-injector concept along with supporting design studies and simulation results.
Paper: WEP1354
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEP1354
About: Received: 13 May 2026 — Revised: 18 May 2026 — Accepted: 21 May 2026 — Issue date: 22 May 2026
WEP1375
NSLS-II Storage Ring Auxiliary Dipole Power Supply
2333
The National Synchrotron Light Source II (NSLS-II) storage ring requires a high-current (400 A), high-voltage (1 kV) dipole power supply system to maintain stable beam operations. Despite the high reliability of the primary system, a 2022 failure event resulted in over 20 hours of beam downtime, highlighting the necessity for enhanced operational resilience. This paper presents the design and implementation of an in-house designed auxiliary dipole power supply system developed to mitigate such risks. The auxiliary system utilizes a modular architecture with N+2 redundancy and high-frequency switched-mode power converters with active power factor correction. This design eliminates large 60 Hz transformers, reducing the system footprint to 10% of the original installation while enabling hot-swappable servicing. A transfer switch ensures a rapid transition from primary to backup systems in under 20 minutes. To maintain stringent orbit stability, the system incorporates a custom DC EMI filter and a series-pass linear amplifier, achieving a measured current stability of 1.71 ppm (DC to 10 kHz). These results demonstrate the system's effectiveness in reducing recovery time and enhancing the overall reliability of NSLS-II beam operations.
Paper: WEP1375
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEP1375
About: Received: 11 May 2026 — Revised: 20 May 2026 — Accepted: 21 May 2026 — Issue date: 22 May 2026
WEP1611
Theory of the waveguide variable power divider and combiner
2354
In theory, a 180° or 90° hybrid bridge can be used as a variable power divider and combiner. This study focuses on the related theoretical research, the Magic Tee and 3 dB bridge are selected as the required 180° and 90° hybrid bridges. Based on scattering matrix of the four-port microwave network, the relationship between the input and output amplitude and phase, the phase difference of the two output signals and the influence of the input amplitude or phase error on the output signals were deduced theoretically. The simulations were also conducted, and the results agreed with theory, which proved the theory correct. The variable power divider and combiner can be used in many applications and thus worth studying.
Paper: WEP1611
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEP1611
About: Received: 30 Apr 2026 — Revised: 18 May 2026 — Accepted: 21 May 2026 — Issue date: 22 May 2026
WEP1613
Development of STCF High-Efficiency Positron Capture Traveling Wave Accelerating Structures
2357
The Super Tau-Charm Facility (STCF) is a next-generation electron-positron collider under development, with a designed center-of-mass energy of 2–7 GeV. Positrons generated by a high-energy electron beam striking a target are captured and accelerated to 200 MeV using large-aperture traveling-wave accelerating structures to reduce beam loss. A constant-aperture cavity geometry, in which the group velocity is controlled by the nose-cone length, is proposed to simplify fabrication while maintaining a high accelerating gradient. A pulse compressor is incorporated into the RF system to further enhance the effective RF power. This paper presents the RF design and optimization of 2 m and 3 m large-aperture accelerating structures, both achieving gradients above 15 MV/m.
Paper: WEP1613
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEP1613
About: Received: 08 May 2026 — Revised: 18 May 2026 — Accepted: 21 May 2026 — Issue date: 22 May 2026
WEP1614
Development of STCF S-Band High-Gradient traveling wave accelerating structures
2361
The Super Tau-Charm Facility (STCF) is a next-generation electron-positron collider project proposed in China, designed to explore frontier physics in the tau-charm energy region. The facility's accelerator is required to provide electron and positron beams with tunable energies ranging from 1.0 to 3.5 GeV. This study presents the design of a traveling-wave accelerating structure for the STCF. By optimizing the regular-cell configuration, a high shunt impedance is achieved. The peak electric field in accelerating structure is reduced by adjusting the accelerating gradient profile, and an under-coupled output coupler design is adopted to enhance the performance of the accelerating structure. The objective is to achieve an accelerating gradient of 22.5 MV/m with an input power of 45.3 MW, and to further increase the power in pursuit of high-gradient operation in the S-band.
Paper: WEP1614
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEP1614
About: Received: 15 Apr 2026 — Revised: 27 Apr 2026 — Accepted: 15 May 2026 — Issue date: 22 May 2026
WEP1615
Beam Adjustment based on the Gradient Boosting Decision Tree Analysis in the KEK Electron/Positron Injector LINAC
2364
KEK-LINAC is an electron/positron linear accelerator used as the injector for the synchrotron radiation facilities (PF ring and PF-AR) and SuperKEKB. The stable operation of experiments at these facilities requires reliable beam supply from the LINAC. We have newly introduced an analytical method based on gradient boosting decision tree (GBDT) to further enhance our beam adjustment capability. GBDT is one of machine learning methods and has been used as an exceptionally effective model for tabular data. The GBDT analysis handling hundreds of LINAC operating parameters predicted accurately beam’s charge and position in the LINAC. Furthermore, by performing SHAP analysis, we have identified key parameters for the beam adjustment and correlations between the parameters. Furthermore, it was found that a model trained by the analyses can be utilized as a surrogate model for fast simulation of beam behavior in the LINAC. The results of beam adjustment with the GBDT analyses will be shown in this presentation.
Paper: WEP1615
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEP1615
About: Received: 12 May 2026 — Revised: 18 May 2026 — Accepted: 20 May 2026 — Issue date: 22 May 2026
WEP1617
Reinstallation of heavy Cryomodule(HWR-A,B) for SCL3 beamline maintenance
2367
This paper presents a case study on the reinstallation of heavy weight cryomodule (HWR-B #11, HWR-A #9 & #13) for the SCL3 beamline maintenance. Our HWR-B combines a cryogenic module with a warm section assembled with a quadrupole magnet and a vacuum chamber, with a total weight exceeding 12.5 tons (HWR-A over 7.0 tons). After each annual beam commissioning, some low-efficiency modules were identified to require functional inspection and repair during maintenance for subsequent beam experiments. In particular, the processes of disassembling a large HWR-B or HWR-A cryomodule from the beamline and moving it out of the underground accelerator tunnel needs very strict safety requirements and detailed planning and coordination among related systems and teams. To perform these tasks efficiently and safely, we prepared pre-designed tools and equipment, formed related work groups for collaboration. During the first stage of the maintenance procedure, the HWR-A/B cryomodules was safely removed from the SCL3 beamline using a specially designed moving wheel and then delivered to the contractor for overhaul. After the overhaul & test were completed, the HWR-B #11 cryomodule was returned to the SCL3 tunnel and reinstalled into its original position in the beamline using the dedicated moving wheels and hydraulics. With great effort and attention, This first in-house beamline maintenance experience provided valuable insight and expertise for the ongoing operation of an accelerator beamline.
Paper: WEP1617
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEP1617
About: Received: 14 May 2026 — Revised: 19 May 2026 — Accepted: 20 May 2026 — Issue date: 22 May 2026
WEP4306
Accelerator upgrades required for beam operation at Fermilab in the PIP-II/DUNE era
2400
The Proton Improvement Plan - II (PIP-II) injector linac is an 800 MeV superconducting H- linac that will replace the existing 400 MeV injector to the accelerator complex at Fermilab. The higher energy, intensity and repetition rate require various upgrades to the existing accelerator complex consisting of the Booster, the Recycler Ring and the Main Injector, in order to be able to accept and accelerate beam from PIP-II. In this paper we discuss the various upgrades that are required and steps being taken to implement them.
Paper: WEP4306
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEP4306
About: Received: 13 May 2026 — Revised: 19 May 2026 — Issue date: 22 May 2026
WEP4313
Exploring Coupled-Cavity Linac upgrade with Distributed-Drive Linac at LANSCE
2407
The Distributed-Drive Linac (DDL) concept allows independent control of the radiofrequency (RF) power and phase of each accelerator cell, realized by an RF power system consisting of discrete solid-state amplifiers (SSAs). The DDL concept is under investigation at Los Alamos Neutron Science Center (LANSCE) as a candidate for the future upgrade of the 805-MHz Coupled-Cavity Linac. Independently adjustable RF power and phase of each DDL accelerator cell allows using the same DDL architecture to provide a much higher beam energy at the linac exit, such as 2-3 GeV, for proton radiography (pRad). The DDL architecture would require significant upgrade of the RF infrastructure at LANSCE, including implementing a great number of phase-coherent coaxial transmission lines for 3000-5000 individual DDL accelerator cells. For the pRad operation mode, compact RF pulse compressors are also under investigation.
Paper: WEP4313
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEP4313
About: Received: 13 May 2026 — Revised: 18 May 2026 — Issue date: 22 May 2026
WEP4314
Plans for cryogenic C-band prototype tests for LANL pRad booster linac
2410
We report the plans for testing a four-cell C-band (5.712 GHz) normal conducting radiofrequency (RF) accelerator cavity at liquid-nitrogen temperature under high accelerating gradient, being prototyped and proposed for the booster linear accelerator (linac) upgrade for the proton radiography (pRad) facility at Los Alamos National Laboratory. Operating RF structures at cryogenic temperature enhances copper conductivity, enabling higher accelerating gradients and greater RF-to-beam power efficiency. The prototype cavity will be housed inside a cryomodule with foam insulation for both low-power and high-power tests. Pulsed RF power up to 12 MW will be available for the high-power experiment. We also report the engineering and mechanical design of the prototype cavity.
Paper: WEP4314
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEP4314
About: Received: 12 May 2026 — Revised: 17 May 2026 — Accepted: 17 May 2026 — Issue date: 22 May 2026
WEP4315
APPLYING MACHINE LEARNING TO LONGITUDINAL PHASE SPACE RECONSTRUCTION IN THE LANSCE CCL
2414
Traditional phase scans at LANSCE are useful for tuning longitudinal capture but provide only indirect information about the bunch distribution. This work extends a deep neural network-based reconstruction method to the first two modules of the side-coupled cavity linac. Simulated two-dimensional phase scans were generated with HPSim by varying the RF phases of Modules 5 and 6 and recording the transmitted current after the absorber/collector diagnostic. A retrained network reconstructed correlated Gaussian longitudinal phase space distributions from these scans, recovering their approximate size, orientation, and centroid. These results support further development using realistic distributions and measured CCL phase scans.
Paper: WEP4315
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEP4315
About: Received: 13 May 2026 — Revised: 21 May 2026 — Issue date: 22 May 2026
WEP4317
Overview of the LAMP Conceptual Design
2417
The LANSCE Accelerator Modernization Project (LAMP) will replace the front-end of the 50-year-old LANSCE accelerator, specifically to maintain beam delivery to all user stations while improving beam availability and reliability. We present an overview of the current LAMP conceptual design, including requirements, beam physics results, design decisions, and key component capabilities.
Paper: WEP4317
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEP4317
About: Received: 13 May 2026 — Revised: 17 May 2026 — Accepted: 17 May 2026 — Issue date: 22 May 2026
WEP4318
LAT: a 9-MeV prototype “front-end” for the LANSCE Accelerator Modernization Project
2421
The LANSCE Accelerator Modernization Project (LAMP) is designing a modernized front-end, up to 100-MeV, for the LANSCE accelerator. The LAMP front-end will replace the two Cockcroft-Waltons with a single Radiofrequency Quadrupole and replace the Drift Tube Linac (DTL) with a modernized version. As part of the Technical Readiness Evaluation there are Critical Technical Elements (CTEs) that need to be addressed for the project to achieve Critical Decision 3. To address these CTEs and as risk mitigation for an accelerator that is in current operation, we plan to assemble LAMP from ion sources through the first DTL Tank, approximately 9-MeV, in an adjacent facility. This paper discusses the current status and future work of this plan: LAT.
Paper: WEP4318
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEP4318
About: Received: 09 May 2026 — Revised: 20 May 2026 — Issue date: 22 May 2026
WEP4319
Performance Boundaries in the Novel Multi-Beam LANSCE Front End
2424
The proposed 100 MeV injector* is designed to renovate LANSCE accelerator facility by replacing the 750-keV Cockcroft-Walton injectors, supporting its unique function of delivering multiple, simultaneous beam flavors to several targets. Accelerating multiple beam types in a single RFQ at LANSCE restricts the ability to optimally tune acceleration and focusing due to inherent differences in beam properties (current, charge per bunch, emittance). Strong beam space charge forces induce coupling between degrees of freedom, leading to an unavoidable mismatch in the Front End that necessitates careful six-dimensional matching with accelerator structures. Unavoidable transients of beam chopping in Low Energy Beam Transport results in development of satellite bunches after 3-MeV RFQ accelerator and necessity to remove them using sophisticated chopper system after RFQ. The paper addresses critical challenges within the proposed Front End and advances solutions for their mitigation.
Paper: WEP4319
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEP4319
About: Received: 01 Apr 2026 — Revised: 18 May 2026 — Accepted: 18 May 2026 — Issue date: 22 May 2026
WEP4320
High-Gradient Booster Linac for Multi-GeV Proton Radiography at LANSCE
2428
Increasing energy of proton beam at the Los Alamos Neutron Science Center (LANSCE) from 800 MeV to 3-5 GeV will improve radiography resolution ten-fold. This energy boost can be achieved with a compact cost-effective linac based on normal conducting high-gradient (HG) RF accelerating structures operating at liquid nitrogen temperatures (cryo-cooled). Such an HG booster is feasible for proton radiography (pRad), which requires short beam pulses at very low duty. The pRad booster starts with a short L-band section to capture and compress the 800-MeV proton beam from the existing linac. The main HG linac will be based on S- and C-band cavities. An L-band de-buncher at the booster end can reduce the beam energy spread if needed for pRad experiments. We are developing proton cryo-cooled HG standing-wave structures with distributed RF coupling for the booster. Prototype cavity structures at S- and C-band are designed and will be tested cryo-cooled to measure breakdowns at high gradients. The booster linac beam dynamics design will also be presented.
Paper: WEP4320
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEP4320
About: Received: 13 May 2026 — Revised: 18 May 2026 — Accepted: 20 May 2026 — Issue date: 22 May 2026
WEP4322
Perspective on Procurements of Major Components for the LANSCE Accelerator Modernization Project (LAMP)
2432
The Los Alamos Neutron Science Center (LANSCE) accelerator delivers different beams to multiple experimental stations simultaneously. These beams have different intensity and time structure. The LANSCE Accelerator Modernization Project (LAMP) seeks to upgrade the technology in the front-end while preserving the unique capabilities of LANSCE. LAMP seeks to replace the two 750-keV Cockroft-Waltons with a single Radio Frequency Quadrupole (RFQ), and a new 100-MeV Drift Tank Linac (DTL). Procurements represent a significant portion of the project’s funding and drive schedule decisions. We discuss the process to procure major accelerator components for LAMP and focus on the RFQ and DTL first tank procurements.
Paper: WEP4322
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEP4322
About: Received: 01 May 2026 — Revised: 18 May 2026 — Accepted: 22 May 2026 — Issue date: 22 May 2026
WEP4329
Requirements Evolution for the LANSCE Accelerator Modernization Project (LAMP)
2439
The Los Alamos Neutron Science Center (LANSCE) consists of an 800-MeV dual-species (H+ and H-) accelerator serving five separate user facilities, each of which can concurrently receive unique beam delivery patterns tailored for their specific requirements. The LANSCE Accelerator Modernization Project (LAMP) will replace the front-end of the 50-year-old LANSCE accelerator, from ion sources through the end of the 100-MeV drift-tube linac, with the goals of maintaining beam delivery capabilities to all user stations while improving reliability and supporting increased operating hours. These goals drive requirements for the LAMP upgrade project as a whole, and flow down into performance specifications for individual subsystems down to the component level. We present an overview of the requirements development process for the LAMP project, and the project’s Key Performance Parameters focused on the upgraded portion of the LANSCE accelerator.
Paper: WEP4329
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEP4329
About: Received: 07 May 2026 — Revised: 19 May 2026 — Issue date: 22 May 2026
WEP4332
The LANSCE Accelerator Modernization Project front-end physics design and model
2446
The Los Alamos Neutron Science Center (LANSCE) accelerator at Los Alamos National Laboratory delivers different beams to multiple experimental stations simultaneously. These beams have different intensity and time structure. The LANSCE Accelerator Modernization Project (LAMP) seeks to upgrade the technology in the front-end while preserving the unique capabilities of LANSCE. LAMP seeks to replace the two 750-keV Cockroft-Waltons with a single RFQ, and a new 100-MeV DTL. New low-energy and medium-energy beam transport lines are necessary to produce the required LANSCE beam patterns. This contribution describes design process and the current state of the LAMP front-end physics model.
Paper: WEP4332
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEP4332
About: Received: 08 May 2026 — Revised: 17 May 2026 — Accepted: 17 May 2026 — Issue date: 22 May 2026
WEP4339
The LAMP RFQTS: Status, Capabilities and Plans
2457
The LANSCE Accelerator Modernization Project (LAMP) will replace the front-end of the existing LANSCE accelerator, from ion sources through the end of the 100-MeV drift-tube linac. The RFQ test stand (RFQTS) currently consists of an H+ ion source, LEBT, and RFQ, but will be expanded to add an H- ion source and LEBT. It is intended as a flexible testing platform for technology maturation and workforce development. This paper will describe the status of the RFQTS, its current and future capabilities and planned experiments for technology maturation and other applications.
Paper: WEP4339
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEP4339
About: Received: 12 May 2026 — Revised: 18 May 2026 — Accepted: 22 May 2026 — Issue date: 22 May 2026
WEP4340
Modelling of Space Charge Compensation in the RFQTS LEBT
2461
The LANSCE Accelerator Modernization Project (LAMP) will replace the front-end of the existing LANSCE accelerator, from ion sources through the end of the 100-MeV drift-tube linac. LAMP, and the RFQ Test Stand (RFQTS), assume high space charge neutralization in the low energy beam transport (LEBT) as solenoids are not sufficient to focus the beams and prevent beam blow up. We present the results of various simulations to find optimum parameters for the beam, the solenoids, the partial compensation factor, as well as emittances for best matching into the RFQ. We compare these results to experiments on the RFQTS beamline with argon gas and present the results.
Paper: WEP4340
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEP4340
About: Received: 07 May 2026 — Revised: 20 May 2026 — Accepted: 21 May 2026 — Issue date: 22 May 2026
WEP4347
The HCHC-X family of high-current compact cyclotrons: design, simulation, tests
2469
The High-Current H<sub>2</sub><sup>+</sup> Cyclotrons (HCHC) were originally conceived for the IsoDAR experiment, which would place an intense accelerator-driven electron-antineutrino source near a high-resolution underground scintillator detector to enable precision beyond-standard-model searches (e.g., sterile neutrino oscillations). The HCHC design accelerates 5 mA of H<sub>2</sub><sup>+</sup> in a compact cyclotron, exploiting vortex motion — a multiparticle collective effect that can stabilize the radial beam size — to reach proton-equivalent currents roughly an order of magnitude beyond commercial cyclotrons. The beam is efficiently bunched by a Radio-Frequency Quadrupole (RFQ) axially embedded in the cyclotron yoke, placing the RFQ exit within 25 cm of the cyclotron median plane. Upon stripping the single binding electron of the H<sub>2</sub><sup>+</sup> (during or after extraction), 10 mA of protons are delivered on target. Because the novel aspects of this design are confined to the first six turns, the concept can be readily adapted to energies from 1.5 to 80 MeV/amu (HCHC-X, where X denotes the energy in MeV/amu). We present the latest HCHC-X family designs, high-fidelity IBSimu/WARP/OPAL simulations incorporating space charge and conducting boundary conditions, and the fabrication status of a 1.5 MeV/amu prototype.
Paper: WEP4347
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEP4347
About: Received: 19 May 2026 — Revised: 20 May 2026 — Accepted: 21 May 2026 — Issue date: 22 May 2026
WEP4349
Recent Developments in DTL Design for LAMP Project at LANL
2478
Linear Accelerator Modernization Project (LAMP) at Los Alamos National Laboratory is under development. One of the significant parts of this project is replacement of the existing 50-years old Drift Tubes Linac (DTL). The perspective DTL will inherit the existing DTL species, namely protons and H- ions, as week as frequency of 201.25 MHz and the output energy of 100 MeV. The input energy of the DTL is determined by the optimization of radio frequency quadrupole (RFQ) and medium energy beam transport (MEBT) optimization, and at present defined as 3.0 MeV. Present paper is focused on the most significant details of the modeling and simulation of the proposed DTL.
Paper: WEP4349
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEP4349
About: Received: 11 May 2026 — Revised: 16 May 2026 — Accepted: 20 May 2026 — Issue date: 22 May 2026
WEP4604
Compensation of second-order random resonances in the J-PARC RCS
2486
In the J-PARC 3-GeV rapid cycling synchrotron, second-order random resonances are excited by shifting the operating point to a higher tune side. To mitigate resonance-induced beam loss and further enhance tunability of the operating point, we studied the compensation of second-order resonances. By controlling the timing when the beam approaches resonance through adjusting the momentum offset and chromaticity-induced tune shift, the optimal resonance compensation is explored, considering the time dependence of lattice imperfections that drive the resonances. The analysis of resonance driving terms and numerical simulation was employed to deepen the understanding of the lattice imperfections. In this article, details of the method and experimental results will be reported.
Paper: WEP4604
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEP4604
About: Received: 16 Apr 2026 — Revised: 16 May 2026 — Issue date: 22 May 2026
WEP4611
Study of energy jitter and energy spread compression for the CSNS-II linac
2502
The China Spallation Neutron Source (CSNS) is currently undergoing an upgrade to increase its beam power from 100 kW to 500 kW. As part of this enhancement, the linear accelerator's beam energy will be boosted from 80 MeV to 300 MeV, and the beam current will be raised from 10 mA to 40 mA. To achieve the higher beam energy, 52 superconducting cavities will be added following the drift tube linac. However, these new cavities are expected to increase both energy jitter and energy spread, potentially leading to significant beam loss during injection into the RCS ring. Therefore, it is crucial to carefully manage the energy jitter and energy spread. This paper first presents simulations of the beam energy jitter and energy spread at the end of the superconducting section with dynamic beam and cavities errors. Subsequently, it introduces a comparison of various compression schemes aimed at reducing energy jitter and energy spread.
Paper: WEP4611
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEP4611
About: Received: 16 Apr 2026 — Revised: 21 May 2026 — Issue date: 22 May 2026
WEP4616
Design of a compact 8-MeV proton linac for medical applications
2506
A 714 MHz proton linac was designed for medical applications. The linac aims for both sychrotrons and S-band linacs. Proton beams can be accelerated to 8 MeV with high transmission.
Paper: WEP4616
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEP4616
About: Received: 13 May 2026 — Revised: 20 May 2026 — Issue date: 22 May 2026
WEP4621
A systematic analysis of cavity compensations in the JAEA-ADS linac utilizing the LightWin tool
2513
The Japan Atomic Energy Agency (JAEA) is designing a 30-MW linear proton accelerator (linac) for the Accelerator-Driven Systems (ADS) to address the nuclear waste storage challenges. For Accelerator-Driven Systems (ADS) technology to be viable, it is necessary to minimize both the number of beam trips and their duration, thereby exceeding the performance of current linacs. JAEA is focused on implementing fast cavity compensation to minimize beam downtime caused by cavity failures. This approach makes rapid cavity retuning that enables a fast beam restoration with an acceptable quality. Beam dynamics studies for the JAEA-ADS linac have shown that it is possible to achieve a proper beam operation even when multiple cavity failures occur. As the JAEA-ADS linac consists of 293 superconducting cavities, it requires a rapid, automated, and systematic approach to determine the optimal readjustment settings for all cavities. To achieve this, we are utilizing the LightWin tool. This software has been developed for ADS linacs and was successfully applied to ADS MINERVA/MYRRHA linac. It has undergone testing and enhancements to improve SPIRAL2 operation. This study analyzes cavity compensation in the JAEA-ADS superconducting linac using the LightWin tool and compares the results with previous research.
Paper: WEP4621
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEP4621
About: Received: 15 Apr 2026 — Revised: 16 May 2026 — Accepted: 16 May 2026 — Issue date: 22 May 2026
WEP4622
Recent Activities at the J-PARC RFQ-TS
2517
The Japan Proton Accelerator Complex (J-PARC) linac delivers the negative hydrogen (H-) ion beam with a peak current of 50 mA to the Material and Life science experimental Facility (MLF) and the Main Ring synchrotron (MR) through the Rapid Cycling Synchrotron (RCS). The Radio-Frequency Quadrupole linac Test Stand (RFQ-TS) in the J-PARC linac building is utilized for the evaluation of the beam quality and the tests of apparatuses by the 3-MeV H- ion beam. Some studies were carried out in the RFQ-TS such as the low-level RF system [1], the novel magnet [2], and the beam monitors [3]. Recently, the performance evaluation of the particle counter system was carried out, which is one of the important apparatuses to operate accelerators safely with the high intensity. In this sense, the points of the improvement were checked for the ion source, cavities, magnets, the RF source, monitors, and the control in the RFQ-TS. The beam test results in the RFQ-TS will be reported in this presentation.
Paper: WEP4622
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEP4622
About: Received: 17 Apr 2026 — Revised: 15 May 2026 — Accepted: 21 May 2026 — Issue date: 22 May 2026
WEP4625
Beam tuning studies for the RAON linear accelerator
2521
Various studies have been conducted to tune the linac. The RF set-points of the superconducting linac is determined with phase scan technique with BPMs. With the BPM calibration, the beam energy is quite accurately determined. We check the beam energy from phase scan with dipole scan method. Transverse beam matching between sections of the linac has been tried successfully. Tomography reconstruction of the beam phase space is also tried from wire-scanner profile measurements and compared with the Allison scanner emittance measurement.
Paper: WEP4625
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEP4625
About: Received: 28 Apr 2026 — Revised: 21 May 2026 — Accepted: 22 May 2026 — Issue date: 22 May 2026
WEP4631
Low-power test of bridge coupler connected to tank in disk-and-washer structure for muon acceleration
2527
A muon linear accelerator is under development at J-PARC for precise measurement of the muon anomalous magnetic moment (g-2) and search for the electric dipole moment (EDM). The disk-and-washer (DAW) structure is employed to accelerate muons from 30% of the speed of light (kinetic energy = 4 MeV) to 70% (40 MeV) at 1296 MHz. The muon DAW consists of tanks accelerating the muons and bridge couplers that couple the tanks and focus the beam using an internal quadrupole doublet. A bridge coupler prototype was fabricated and tested at low power. This Low-power test focused on measuring resonant frequencies, Q-value, and electric field distribution. Furthermore, the bridge coupler prototype was connected to a tank prototype and tested at low power to understand the effects of the connection. This paper summarizes these results and discusses the prospects for actual machine production.
Paper: WEP4631
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEP4631
About: Received: 01 Apr 2026 — Revised: 29 Apr 2026 — Accepted: 14 May 2026 — Issue date: 22 May 2026
WEP4633
Design of a dual extraction system for the ultra-compact multifunctional cyclotron CYCIAE-36A
2531
The growing demand for medical isotopes and mobile neutron sources has motivated the development of compact and multifunctional accelerators. The China Institute of Atomic Energy has developed an ultra-compact superconducting cyclotron, CYCIAE-36A, capable of accelerating H₂⁺ and α particles and delivering proton and α beams for applications including ²¹¹At production, PET isotope supply, α-irradiation studies, and neutron imaging. The highly compact layout poses significant challenges for beam extraction. A dual extraction system combining electrostatic deflection and carbon-foil stripping is proposed under the constraints of superconducting magnets, RF cavities, and limited space. In this scheme, α particles are extracted using an electrostatic deflector, while H₂⁺ ions are extracted by stripping, enabling variable-energy proton beams in the opposite direction. Phase width control is critical for extraction efficiency. A fixed-phase selector was implemented in the central region to optimize α-beam extraction. Particle tracking simulations starting from the central region assume phase widths of 20° for α particles and 50° for H₂⁺ ions, yielding extraction efficiencies of 65% and 99%, respectively. In addition, the effects of 1st and 2nd harmonic magnetic field components introduced by the magnetic channels during precession extraction were analyzed, and corresponding compensation methods were developed to mitigate their impact on beam dynamics.
Paper: WEP4633
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEP4633
About: Received: 13 May 2026 — Revised: 20 May 2026 — Issue date: 22 May 2026
WEP4638
Magnetic field interference and compensation of quadrupole magnets in CSNS RCS
2535
During the beam power upgrade of the Rapid Cycling Synchrotron (RCS) of the China Spallation Neutron Source (CSNS), 16 additional trim quadrupoles were installed for beam optics correction. However, they are relatively close to the nearby main quadrupole magnets, resulting in a strong field interference effect. The interference causes a serious distortion of the lattice parameters and can lead to significant beam loss for high-intensity beams. In this paper, firstly, the three-dimensional electromagnetic field software OPERA is used for simulation, and the magnetic field integral changes are accurately calculated. Then, a systematic analysis was conducted on the effects of integrated magnetic field variations on both the betatron tune and beta function using the accelerator physics calculation software MADX. Additionally, the multi-particle tracking software pyORBIT is utilized to simulate beam loss. The results show that the original lattice parameters are distorted and beam loss is significantly increased by this effect. To obtain accurate magnetic field interference data, indirect measurements were performed employing the orbit response matrix method. Experimental results demonstrate remarkable consistency with numerical simulations. On this basis, beam compensation experiments are carried out and beam loss is successfully reduced.
Paper: WEP4638
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEP4638
About: Received: 15 Apr 2026 — Revised: 18 May 2026 — Issue date: 22 May 2026
WEP4639
Commissioning at the tunes below half-integer for CSNS RCS
2539
Based on the beam commissioning of CSNS-I RCS, the current tune above half-integer exhibits extremely small parameter margins and severe instabilities. Therefore, to further increase beam power in Phase II, significant optimization of the tune is required.Through extensive simulations, we identified that the tunes below half-integer (near 4.3/5.3) show no instabilities, which is crucial for power enhancement in Phase II. To verify stable operation at the tunes of this region in the actual machine, we conducted a series of machine studies. The results demonstrate that the tunes below half-integer is instability-free and can achieve stable beam supply at 140 kW (corresponding to 700 kW in Phase II under equivalent tune shift due to space charge).
Paper: WEP4639
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEP4639
About: Received: 12 May 2026 — Revised: 20 May 2026 — Issue date: 22 May 2026
WEP4644
Longitudinal beam dynamics simulation for gold ion acceleration in the J-PARC MR
2542
The J-PARC Main Ring (MR) is a high-intensity proton synchrotron, which accelerates protons from 3 GeV to 30 GeV. In addition to protons, we are considering accelerating heavy ions to GeV/u energies in the MR as part of the J-PARC heavy-ion program (J-PARC HI). The heavy ions will be injected from the new heavy-ion injector into the J-PARC Rapid Cycling Synchrotron (RCS) and delivered to the MR. As the first stage of the program, Au ions are considered the ion species to accelerate. A full stripping beam of Au ions ($^{197}$Au$^{79}$ ) with an energy of 500 MeV/u is injected from the RCS to the MR. Au ions are accelerated up to 11.5 GeV/u and delivered to the hadron experimental facility. Since the change in revolution frequency during acceleration of Au ions is larger than that for protons, additional cavities dedicated to ion acceleration or modifications to the existing RF cavity will be needed to cover a wider frequency range. To estimate the RF system requirements for accelerating Au ions in the MR, we conducted a longitudinal beam dynamics simulation. In this presentation, we present the simulation results with various harmonic numbers and acceleration times.
Paper: WEP4644
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEP4644
About: Received: 15 Apr 2026 — Revised: 16 May 2026 — Accepted: 17 May 2026 — Issue date: 22 May 2026
WEP4647
Development of a Gas-Target Laser Ion Source Test System for the LaPRIS Concept
2549
In order to achieve high energy resolution in nuclear physics experiments, it is important to maintain the beam quality during beam transport from the injector to the accelerator and to the experimental instruments. At the Research Center for Nuclear Physics (RCNP), the University of Osaka, high-resolution beams are currently obtained by injecting beams from an ECR ion source into the accelerator and collimating them with slits throughout the acceleration. However, this method leads to increase losses of beam intensity and a beam halo, so it is desired to generate high-quality beams directly at the ion source without collimations. As a solution to the issues, we are developing the LaPRIS (Laser Plasma RF Ion Source) method. LaPRIS is a pulsed ion source that generates and extracts slow ions by combining a gas jet, an RF field and ultra short pulse laser. In this method, the ions are extracted from plasma generated at the laser focal spot by RF field. They form a short-pulsed bunch with a small spatial and time profile. In this paper, we will discuss preliminary results obtained by generating laser-induced plasma through focused laser in a jet of thin gas and measuring the generated ions.
Paper: WEP4647
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEP4647
About: Received: 13 May 2026 — Revised: 19 May 2026 — Issue date: 22 May 2026
WEP4658
operational experiences and upgrade of CSNS ion source
2572
The CSNS ion source has been in operation over 10 years since 2015. It has provided a stable beam current, progressing from an initial beam commissioning power of 10 kW to the current 170kW. The CSNS ion source is responsible for delivering 30-40 mA H- at 50kV. During CSNS phase I, a Penning surface negative ion source was used, based on the ISIS ion source prototype. It met the operational requirement of 100 kW beam power of CSNS phase I. However, due to its short lifetime, typically requiring replacement every month, and its relatively large emittance, it faced significant challenges as the beam power target for CSNS phase II is raised to 500 kW. To address this, an RF ion source was proposed and its development began in 2016. This volume ion source has been successful used in SNS and JPAC and offer some advantages such as a longer lifetime, lower emittance, lower cesium consumption. Unlike the internal antenna design used by SNS and JPAC, an external antenna RF ion source was successful developed and put into operation in September 2021. This paper will discuss the extensive operational experience with the ion source and the development process of the RF ion source.
Paper: WEP4658
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEP4658
About: Received: 09 May 2026 — Revised: 17 May 2026 — Accepted: 17 May 2026 — Issue date: 22 May 2026
WEP5004
Beamline Extension Considerations for AREAL-50 Accelerator
2579
AREAL linear accelerator, presently operating at CANDLE SRI generates 5-MeV ultrashort electron beams for a wide range of applications. The planned upgrade program aims to increase the beam energy up to 50 MeV in order to expand experimental capabilities and enable the generation of THz radiation. For this purpose, two 1.6-m-long accelerating structures are foreseen to be installed. To ensure optimal beam parameters for efficient acceleration and high-quality beam delivery, existing magnetic and diagnostic systems must be modified and supplemented. In this paper, several aspects of the new beamline design are examined, and the corresponding beam dynamics studies for the proposed layout are presented.
Paper: WEP5004
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEP5004
About: Received: 13 May 2026 — Revised: 21 May 2026 — Issue date: 22 May 2026
WEP5005
Cavity Failure Compensation Study in Spiral 2 LINAC: Simulation and Experimentation
2583
The SPIRAL2 LINAC at GANIL (Caen, France) was commissioned in 2019 and became operational for users in 2022. During these years, there have been various issues with amplifiers and cavities, which have caused the LINAC to operate without a cavity. Within the framework of the ReFilL project, several cases with one cavity out of order were simulated with TraceWin. Three cases were tested experimentally in 2024 with a 5mA deuterium beam. In 2025, following a leak in the cavity CMA11, the LINAC has been operated without this cavity for two months. Demonstrating the feasibility of cavity failure compensation under operational conditions. We fully characterized the CMA11-out-of-order configuration, and investigated two additional cases with a second inactive cavity: CMA01--CMA11, CMA11--CMA12. In both cases, nominal beam energy was successfully recovered. This article presents results of these studies and perspectives for cavity compensation at GANIL.
Paper: WEP5005
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEP5005
About: Received: 19 May 2026 — Revised: 21 May 2026 — Issue date: 22 May 2026
WEP5018
Ultralow-Alpha Operation with three Families of Sextupoles at the KARA Ring
2599
For more than two decades, the Karlsruhe Research Accelerator (KARA) — KIT’s synchrotron radiation source and accelerator test facility — has been routinely operated in short-pulse mode, which involves reducing the momentum compaction factor. Recent advancements, such as enhanced stability provided by new magnet power supplies, have enabled us to surpass previous limitations in achieving extremely small momentum compaction factors. Based on lattice simulations and the introduction of a single additional sextupole magnet we successfully suppressed the longitudinal chromaticity, allowing the “zero-current” bunch length at KARA to be reduced from the previous 2 ps to below 1 ps. We further report on characterization measurements of this improved operating mode.
Paper: WEP5018
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEP5018
About: Received: 13 May 2026 — Revised: 19 May 2026 — Issue date: 22 May 2026
WEP5020
Modeling of Multiturn Injection at SIS-18 for a Train of UNILAC Microbunches
2606
Multiturn Injection is an essential tool for achieving high beam intensities in synchrotrons. At SIS-18, a significant increase in the intensity of the uranium beam is foreseen, by several orders of magnitude up to 1.5x10e15 ions per injection cycle, prior to acceleration and extraction to SIS-100. Under these conditions, any beam losses during injection become critical, both in terms of beam lifetime and the risk of damaging injection system components, in particular the electrostatic septum. Usually, the optimization of the multiturn injection is carried out by considering only the process of injecting one transverse slice of macroparticles from UNILAC per turn. We present here a three-dimensional modeling of the injection process, which takes into account the longitudinal structure of the injected beam, namely the train of microbunches, and evaluates differences from previous approaches.
Paper: WEP5020
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEP5020
About: Received: 15 Apr 2026 — Revised: 20 May 2026 — Issue date: 22 May 2026
WEP5023
Improving Energy Spread of MESA Beam in ERL Operation
2614
MESA, the Mainz Energy-Recovery Superconducting Accelerator, currently under commissioning at Johannes Gutenberg University Mainz, is designed to operate in two modes: external beam (EB) mode, with 150 μA polarized electrons at 155 MeV serving the P2 experiment, and energy-recovery linac (ERL) mode, with an unpolarized beam of 1–10 mA at up to 105 MeV for the MAGIX experiment. The latter requires precise control of the energy spread and the bunch length across various beam energies of 30, 55, 80, and 105 MeV. Comprehensive simulations were conducted using the tracking code ELEGANT; starting with a 4-ps bunch length, the full acceleration and deceleration process in ERL mode was modeled by optimizing the RF phase and the accelerating gradient field in off-crest operation, which results in the desired energy gain in each linac section. To reach the lowest energy spread, an appropriately selected longitudinal dispersion in the recirculation arcs is required. Since the beam is more sensitive to RF curvature and space-charge effects at low energies, reducing the bunch length by 50 % results in a small energy spread. Consequently, the injection arc lattice is optimized by adjusting the arc momentum compaction R56 as the primary tuning parameter. The integration of a chirp and R56 tuning enables efficient, controlled bunch compression and thereby enhances the overall beam quality.
Paper: WEP5023
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEP5023
About: Received: 15 Apr 2026 — Revised: 17 May 2026 — Accepted: 17 May 2026 — Issue date: 22 May 2026
WEP5027
Applications of High-Dimensional Time-Delayed Embedding for Time Series Complexity Estimation
2622
Turn-by-turn (TbT) data are readily available in modern circular accelerators and are widely used to infer machine parameters in both simulations and experiments. In the latter case, TbT data record transverse beam-centroid positions from beam position monitors (BPMs) and therefore include measurement noise and decoherence. We construct high-dimensional time-delay embedding of TbT time series, yielding matrix representations of the signals. Since the signals considered are typically near-quasiperiodic with harmonics of the fundamental betatron frequencies, the embedded matrices are expected to be low-rank. We leverage this rank structure to define a complexity indicator on singular-value spectra, which are related to the underlying quasiperiodic structure of the TbT signals.The proposed framework provides a simple, data-driven diagnostic for complexity estimation directly from TbT records and is compatible with experimental datasets.
Paper: WEP5027
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEP5027
About: Received: 06 May 2026 — Revised: 17 May 2026 — Accepted: 17 May 2026 — Issue date: 22 May 2026
WEP5028
Estimating the Stability Domain of Symplectic Maps: A Robust Method via Bounding Set of Unstable Initial Conditions
2627
Estimating the stability domain in view of its characterization and optimization is one of the primary topics of single-particle non-linear beam dynamics. The border of the stability domain or dynamic aperture (DA) has a complicated fractal boundary that cannot be reliably estimated by analytical means. Instead, a numerical computation is used to estimate the DA with the additional constraint of determining only the simply connected domain around the origin. The most common case of a DA estimate for 4D systems can be reduced to a 2D polar grid scan, which reduces the computational burden. Here we present a new robust method of DA characterization by constructing a cloud of escaping initial conditions that bound the stable domain and has a significantly reduced computational complexity compared to a direct scan of phase-space variables. The proposed method is applied to a non-linear 4D symplectic polynomial map and the results compared against what found with the standard methods, both in terms of numerical accuracy and of CPU time.
Paper: WEP5028
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEP5028
About: Received: 09 May 2026 — Revised: 17 May 2026 — Accepted: 17 May 2026 — Issue date: 22 May 2026
WEP5038
Modeling and Field Analysis of the LEIR Bending Magnets and Optics Integration
2648
This contribution presents the modeling of the dipole magnets of the Low-Energy Ion Ring (LEIR) at CERN. The LEIR dipoles are iron-dominated C-type 90° sector magnets. Each LEIR dipole consists of 6 blocks of 1-meter-long laminated steel yoke with copper coils. The biggest challenges of the design stem from the axial air gaps and the varying angles between the blocks, causing unwanted harmonics in the magnetic field. These harmonics cause mismatches between measured and predicted linear optics parameters in LEIR. Due to the unconventional magnet design, efforts are made to obtain 3D field maps and multipole field components with high accuracy by modelling the magnet precisely in 3D. The study has started with 2D Finite Element Analysis (FEA) in different cross-sections and then continued with the 3D FEA analysis for the examination of the integrated field and the multipole components. The FEA is computed using different programs for comparison and to increase the model accuracy by fine-tuning. Finally, the model results have been compared with the beam-based optics measurements, and the efficiency of the models has been evaluated.
Paper: WEP5038
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEP5038
About: Received: 13 May 2026 — Revised: 19 May 2026 — Issue date: 22 May 2026
WEP5041
Understanding energy-induced optics distortions in the LHC
2660
Small momentum offsets in the LHC can generate significant optics distortions, particularly at low $\beta$*. The beam energy carries a relative uncertainty of approximately $10^{-3}$, which is insufficient for precise optics control. To better understand the impact of energy on the optics, two beam-based techniques have been explored. The first applies a global linear response matrix between BPM phase advances and $\Delta p/p$; while effective in simulation, this method is sensitive and does not reproduce the response observed in the machine. We introduce a new approach based on the principle of Deep Lie Map Networks (DLMN), which fits turn-by-turn BPM trajectories to a differentiable tracking model. Using the single-pass forward differentiation capability of MAD-NG, derivatives of the orbit with respect to $\Delta p/p$ are computed directly within the symplectic tracking engine. The results reveal arc-by-arc variations consistent with dipole-induced orbit distortions, providing insight into orbit behaviour around the ring. The measured response also agrees with that observed in the machine, demonstrating that the DLMN offers a promising new method for analysing the effect of energy on the optics of the LHC.
Paper: WEP5041
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEP5041
About: Received: 17 Apr 2026 — Revised: 15 May 2026 — Issue date: 22 May 2026
WEP5042
Deep Lie map networks from single-pass forward differentiation
2664
Deep Lie Map Networks (DLMN) were introduced in earlier work as an optimisation framework that adjusts lattice parameters by fitting simulated beam trajectories to measured BPM data. In this contribution, we present a new implementation of DLMN based on the single-pass forward differentiation capability of MAD-NG, allowing exact derivatives of the particle coordinates with respect to lattice parameters to be computed during tracking. Unlike approaches that rely on back propagation or finite differences, this method performs gradient evaluation directly inside the symplectic tracking engine. This enables efficient gradient-based fitting of lattice parameters with improved memory efficiency and reduced computation time. The work demonstrates that differentiable, symplectic tracking provides a powerful foundation for data-driven optics modelling and establishes DLMN-in-MAD-NG as a scalable tool for future accelerator studies. Looking ahead, this framework could form a key component toward a real-time digital twin of accelerator lattices, where machine settings and model parameters are continuously inferred from live measurements.
Paper: WEP5042
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEP5042
About: Received: 04 May 2026 — Revised: 17 May 2026 — Accepted: 22 May 2026 — Issue date: 22 May 2026
WEP5051
Beta Function Measurements using Quadrupole Variation in SLS 2.0
2688
The Swiss Light Source upgrade, SLS 2.0, is a fourth generation storage ring based on a seven-bend achromat design and is currently under commissioning. Precise knowledge and control of the linear optics are essential for optimal machine performance. This contribution presents measurements of the beta function using the quadrupole variation method at 264 locations around the ring. The corresponding tune shifts were determined with high resolution via the mixed BPM technique combined with Numerical Analysis of Fundamental Frequencies (NAFF).
Paper: WEP5051
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEP5051
About: Received: 07 May 2026 — Revised: 17 May 2026 — Accepted: 17 May 2026 — Issue date: 22 May 2026
WEP5074
Advanced Linear and Nonlinear Optics Studies Using MAD-NG’s Parametric Differential Algebra.
2720
Advanced linear and non-linear optics studies require accurate and efficient tools for high-order beam dynamics computations. MAD-NG provides a unique framework combining linear and nonlinear optics modelling, high-order parametric differential map computation through precise automatic differentiation, and Lie-algebraic operations central to nonlinear normal form analysis, all within a unified environment based on the Generalised Truncated Power Series Algebra (GTPSA). These capabilities enable accurate evaluation of optical functions, chromatic effects, and nonlinear Hamiltonian dynamics. MAD-NG embeds LuaJIT, a high-performance scripting engine, offering automated workflows, symbolic dependencies, and deferred evaluations for efficient lattice design and parametric optimisation. It has been successfully used to improve the LHC beam lifetime at injection (2023) and during collisions (2025) by minimisimg resonant driving terms. Applied to major projects such as the LHC, HL-LHC, and FCC-ee, MAD-NG demonstrates reliability, scalability, and accuracy for large-scale optics and sensitivity studies while providing a flexible, reproducible, and high-performance environment for modern accelerator modelling and advanced beam dynamics research.
Paper: WEP5074
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEP5074
About: Received: 13 May 2026 — Revised: 21 May 2026 — Issue date: 22 May 2026
WEP5076
Tests of commissioning simulation tools in operation of storage ring light sources
2728
The design of 4th generation synchrotron light sources employs such strong quadrupolar and sextupolar magnets, that the motion of electrons in the storage ring is extremely sensitive to the misalignment and the field imperfection of magnets. As a result, it has become common practice to simulate the steps followed during the commissioning of a light source to compare the sensitivity to different types of lattice errors from a beam dynamics point of view and inform the design of the light source. Although there is significant overlap in the algorithms used to commission and to simulate the commissioning of a light source, they typically consist of separate implementations. This work describes the latest developments in the pySC software for commissioning simulations to allow the usage of its tools in a real control system environment for storage rings. Finally, it reports on tests done at the European Synchrotron Radiation Facility Extremely Brilliant Source (ESRF-EBS) to apply said tools to tune the storage ring.
Paper: WEP5076
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEP5076
About: Received: 13 May 2026 — Revised: 21 May 2026 — Issue date: 22 May 2026
WEP5083
Assessment of fabrication and assembly tolerances in an IH-DTL cavity through electromagnetic and beam dynamics Simulations
2751
This work presents a comprehensive study of manufacturing and assembly errors in a 750 MHz Interdigital H-mode Drift Tube Linac (IH-DTL) cavity designed for a compact and efficient ion beam inyector. Operating at such a high RF frequency significantly reduces the cavity dimensions but it also increases the sensitivity to geometric imperfections, posing a substantial technological challenge for manufacturing and assembly. In this study, realistic machining deviations — including drift-tube misalignments, stem eccentricity, profile machining errors, and end-cell distortions — are introduced within typical fabrication tolerances. Three-dimensional electromagnetic simulations quantify the resulting perturbations in the resonant frequency, accelerating fields, and power efficiency. First, the most critical geometric perturbations were identified by means of a single cavity cell model. Then, those errors were implemented in a complete cavity, applied to all cells. The resulting field maps were subsequently imported into multi-particle beam dynamics simulations to evaluate their impact on beam quality, transmission, and emittance growth. The study provides experimental tolerance thresholds and offers guidance for cavity fabrication, quality control, and commissioning strategies for IH-DTL structures.
Paper: WEP5083
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEP5083
About: Received: 13 May 2026 — Revised: 20 May 2026 — Issue date: 22 May 2026
WEP5084
A comprehensive analytical model for RFQ beam dynamics
2755
The Radiofrequency Quadrupole (RFQ) is the initial accelerating device in many modern linear accelerators (linacs), such as the European Spallation Source (ESS), where it accelerates protons from 75 keV to 3.6 MeV. Due to its complex geometry, RFQ beam dynamics are typically studied using finite element solvers, which, while accurate, are computationally intensive and unsuitable for online modeling. The widely used analytical "two-term" model, originally introduced by I. M. Kapchinsky and V. A. Teplyakov, provides a faster alternative but often suffers from inaccuracies, with errors in particle dynamics tracking reaching up to 20\%, particularly with high-intensity beams. This paper presents a comprehensive analytical model for the RFQ, detailing how to derive its coefficients based on boundary conditions induced by the RFQ geometry and demonstrating its application for particle transport simulations.
Paper: WEP5084
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEP5084
About: Received: 11 May 2026 — Revised: 19 May 2026 — Accepted: 20 May 2026 — Issue date: 22 May 2026
WEP5086
Analytical solutions for particle tracking in planar crystal channelling
2759
Planar particle channelling describes the motion of high- energy particles trapped in the potential well formed by crystal lattice planes, allowing their trajectories to be de- flected in a controlled manner. Within the Molière approx- imation, which incorporates atomic screening and thermal vibrations, this motion is typically either approximated by a harmonic potential or evaluated numerically. Here, we propose a simplified Molière model that yields closed-form analytical solutions expressed through Jacobi elliptic func- tions. To extend the treatment to bent crystals, symplectic integrators are applied to the equations of motion, ensuring accuracy and long-term stability through symplecticity. This semi-analytical approach to evaluate bent channelling has been benchmarked against existing numerical methods, and the optimal configuration has been integrated into Xsuite’s Xcoll package.
Paper: WEP5086
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEP5086
About: Received: 16 Apr 2026 — Revised: 19 May 2026 — Accepted: 21 May 2026 — Issue date: 22 May 2026
WEP5089
HOM study of the PERLE’s booster cavity
2767
The injector for the PERLE ERL in construction at IJCLab is based on a booster containing 4 superconducting cavities to reach 7 MeV for 20 mA of cw current. The cavities are single cell at 801.58 MHz. Due to the high average current, issues of beam break-up and power dissipation induced by the higher order modes of the cavities are a matter of concern. In this paper, we will report on the systematic survey of the HOM thanks to CST simulations up to 8 GHz. An analysis of their harmfulness as a function of the current spectrum will be shown.
Paper: WEP5089
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEP5089
About: Received: 12 May 2026 — Revised: 18 May 2026 — Accepted: 19 May 2026 — Issue date: 22 May 2026
WEP5090
Status of the PERLE’s injector
2770
The ERL accelerator called PERLE is under construction on the campus of Paris-Saclay university. PERLE is an Energy Recovery Linac which aims to reach 250 MeV 20 mA cw, namely 5 MW of beam power. First brick of this accelerator is the injector whom the main components are the DC photo-injector and a booster holding 4 superconducting cavities. This paper will give an overview of the injector’s design, technical details about major components and the schedule of the construction.
Paper: WEP5090
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEP5090
About: Received: 12 May 2026 — Revised: 16 May 2026 — Accepted: 17 May 2026 — Issue date: 22 May 2026
WEP5091
Improved resistive wall effective radius taking into account Yokoya factors
2774
When computing the resistive wall impedance, one must account for variations in beam pipe aperture, conductivity, and beta function. This can be done by either summing individual contributions or using an "effective radius" in an analytic formula. However, the standard "effective radius" formula has limitations: it ignores cross-plane influences and lacks formulas for quadrupolar or monopolar wakes. This paper introduces an improved "effective radius" definition using Yokoya factors, addressing these limitations. This updated formula was used to develop SOLEIL’s new impedance model, significantly improving the agreement between simulated and measured instability thresholds.
Paper: WEP5091
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEP5091
About: Received: 15 Apr 2026 — Revised: 04 May 2026 — Accepted: 15 May 2026 — Issue date: 22 May 2026
WEP5102
Challenges in beam coupling impedances for FCC-ee
2798
A comprehensive impedance model is required to ensure beam stability and optimize performance in the FCC-ee main rings. The model integrates contributions from a wide range of components, accounting for both resistive-wall and geometric effects. In this paper, we discuss the main challenges introduced by the peculiar FCC-ee parameter regime. A first difficulty arises from the combination of large beam-pipe dimensions and very short bunch lengths, which drives wakefield simulations into an extremely demanding computational regime, where very fine spatial resolution is necessary to accurately capture the beam–environment interaction. In addition, the beam-pipe cut-off lies within the frequency range excited by the FCC-ee beam. As a consequence, several higher-order modes may propagate over long distances, leading to non-local impedance effects and possible crosstalk between different accelerator elements. This means that the impedance environment cannot be treated as purely local, but requires a distributed description and an assessment of how propagating power is transported and potentially absorbed within the machine.
Paper: WEP5102
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEP5102
About: Received: 13 May 2026 — Revised: 18 May 2026 — Issue date: 22 May 2026
WEP5114
Characterization of longitudinal electron beam quality at the soft X-ray beamline of SwissFEL
2834
Longitudinal electron beam quality is key at X-ray free-electron lasers (FELs), where electron beams with small slice energy spread and a well-preserved current profile are required to ensure optimal, stable performance. Collective effects such as microbunching instability (MBI) and intrabeam scattering (IBS) can significantly degrade the longitudinal phase-space of the electron beam during multi-stage compression and are therefore a concern across FEL facilities. In this contribution, we will present systematic characterization studies of these mechanisms at the SwissFEL soft X-ray beamline Athos. We will show longitudinal phase-space measurements using radiofrequency transverse-deflecting structures for different accelerator and compression conditions. These characterization studies represent a first step towards the optimization of multi-stage compression schemes aimed at mitigating MBI and IBS effects.
Paper: WEP5114
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEP5114
About: Received: 08 May 2026 — Revised: 12 May 2026 — Accepted: 21 May 2026 — Issue date: 22 May 2026
WEP5120
Beam Dynamics Study for a Modified Low-Emittance RF Photogun
2854
High-brightness and low-emittance beams generated in RF-gun–based accelerators are essential for a number of applications, such as free-electron lasers (FELs), ultrafast electron Diffraction facilities and THz radiation sources. In these accelerators, the final beam characteristics are determined both, by the properties of the electron gun and by the influence of the electromagnetic system along the beamline. To meet the requirements imposed on beam characteristics, it is essential to identify the optimal parameters of the RF gun and the magnetic system. In this paper, beam dynamics studies of a modified RF photogun for the AREAL and REGAE accelerators are presented, with emphasis on transverse emittance compensation. Simulations were conducted by adjusting the parameters of the focusing and RF systems to identify the optimal configuration of the modified RF gun.
Paper: WEP5120
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEP5120
About: Received: 13 May 2026 — Revised: 21 May 2026 — Issue date: 22 May 2026
WEP5128
Ion transport optimisation at the Low Energy Branch
2869
In every accelerator beamline, the goal is to achieve the highest possible desired beam throughput. When the beamline consists of only a few ion optical elements, beam transport optimization is achieved by adjusting a few knobs, by an experienced operator. At the Jožef Stefan Institute, we are currently developing the Low Energy Branch (LEB) *, designed for high-precision ion implantation. The branch operates in a versatile regime of beams spanning the entire periodic table at various ion energies. This versatility makes beam transport optimization challenging, even for experienced operators, despite the limited number of ion optical elements: Einzel lenses, an electrostatic beam bender, x-y steerers, a Wien filter, and a 90-degree dipole magnet. In this proceeding, we present the cost functions for optimizing ion transport through the LEB and describe how we determine the optimal settings for the LEB's optical elements. The optical elements are modeled using first-order transfer matrix formalism, with the figure of merit for beam optimality measured by Faraday cups and Allison emittance scanner**. The beam element parameters are controlled via the EPICS control system***.
Paper: WEP5128
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEP5128
About: Received: 13 May 2026 — Revised: 19 May 2026 — Issue date: 22 May 2026
WEP5132
Fast and accurate accelerator modelling with FLUKA CAD geometry workflow
2881
Accurate geometric representation is essential in accelerator beam-matter interaction Monte-Carlo simulations, yet conventional Constructive Solid Geometry (CSG) modeling of beamline elements or tunnels remains time-consuming and error-prone. Recent FLUKA developments offer a robust alternative to manual CSG implementation by introducing a CAD-based (Computer Aided Design) workflow. The new approach supports CAE (Computer Aided Engineering) volumetric meshes and the direct import of meshes generated in Gmsh, Ansys, or Abaqus. This workflow is expected to accelerate model development, particularly for complex geometries. Benchmark comparisons will be presented between FLUKA conventional CSG geometries, FLUKA CAE-mesh geometries, and an independent development carried out in Geant4 to support CAD surface meshes: the results demonstrate that while CAE meshes introduce a modest performance penalty, they provide substantial gains in accuracy, maintainability, and interoperability across design and simulation environments.
Paper: WEP5132
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEP5132
About: Received: 13 May 2026 — Revised: 19 May 2026 — Issue date: 22 May 2026
WEP5134
A spacial Boris-like scheme for particle tracking in magnetostatic field: impleamentation and properties
2885
Accurate and stable integration of charged-particle motion in complex magnetic fields is essential for beam-dynamics simulations in accelerators and beam lines. For the Xsuite simulation framework we have recently developed a spatially discretized Boris-like algorithm that advances particle coordinates using the longitudinal position as the independent variable. The scheme retains the symmetric kick–rotate–kick structure of the standard time-based Boris pusher, ensuring exact preservation of the total momentum magnitude and of the phase-space volume. We derive its formal properties using operator-splitting and backward-error analysis, showing that it is second-order accurate, and that the symplectic error scales quadratically with the integration step. Such properties are also verified by numerical tests on representative field distributions.
Paper: WEP5134
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEP5134
About: Received: 12 May 2026 — Revised: 18 May 2026 — Accepted: 22 May 2026 — Issue date: 22 May 2026
WEP5137
Xboinc: A framework for volunteer-based beam dynamics simulations using Xsuite
2889
The Xboinc Python package extends the LHC@Home volunteer computing project by integrating the Xsuite simulation toolkit within the BOINC platform. Designed to be the successor to SixTrack's BOINC implementation, the Xboinc framework enables large-scale single-particle tracking based on the novel simulation package Xsuite. Using the computational power of global volunteer computing, Xboinc on LHC@Home provides scalable resources for advanced accelerator physics simulations, such as dynamic aperture studies. The previous functionalities were extended, notably by enabling collimation performance and loss map simulations thanks to the new Xcoll implementation in Xsuite. The synergy between distributed computing and public engagement ensures the continuity of volunteer contributions to particle accelerator research and paves the way for present and future large-scale simulation campaigns.
Paper: WEP5137
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEP5137
About: Received: 07 May 2026 — Revised: 22 May 2026 — Issue date: 22 May 2026
WEP5138
Progress and Developments of Beam Delivery Simulation (BDSIM)
2893
Beam Delivery Simulation (BDSIM) is a Monte Carlo program (written in C++ ) that creates a 3D radiation transport model designed for the simulation of accelerators and beamline modelling. BDSIM uses Geant4 for precise particle-matter interactions combined with particle-tracking through 3D geometries of accelerators and their environments. All particle species are tracked, allowing for studies for collimation, beam losses, secondary radiation generation, and dosimetry. BDSIM allows for detailed customisation, with numerous applications in the design of high-energy physics facilities, medical beamlines, particle detection experiments, and novel acceleration experiments. Recent developments to BDSIM are presented, including; updated BDSIM deployment methods, development of regression testing, coupling between Xsuite, RF-track and bdsim, updates to the muon cooling modelling, updates to medical modelling for loading DICOM files, applications of BDSIM for FCC-ee, and general updates including optical physics examples. Information on the formation of the BDSIM collaboration community are also detailed.
Paper: WEP5138
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEP5138
About: Received: 13 May 2026 — Revised: 21 May 2026 — Issue date: 22 May 2026
WEP5303
Data-driven reconstruction of accelerator lattice errors using three beam position monitors
2913
There are numerous experimental techniques to quantify errors in a particle accelerator so that they can be corrected to improve the performance of the accelerator. However, these techniques are often limited in scope, for example, identifying only the errors in quadrupole strengths, sextupole strengths, or the centers of these magnets. In this paper, we propose a data-driven method that can estimate many parameters of lattice elements, including those mentioned above, based solely on many sets of transverse position readings in a section that spans three beam position monitors. Preliminary simulation results will be reported.
Paper: WEP5303
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEP5303
About: Received: 13 May 2026 — Revised: 19 May 2026 — Issue date: 22 May 2026
WEP5304
Adjoint Sensitivity Analysis for Design and Optimization
2917
The design of accelerator lattices involves evaluating and optimizing Figures of Merit (FoMs) that characterize a beam’s properties. These properties—hence the FoMs—depend on the many parameters that describe a lattice, including the strengths, locations, and possible misalignments of focusing elements. Often what is required is the gradient of the FoM with respect to each of the parameters. For systems that require numerical simulation, a naïve computation of a gradient requires one simulation for the “base case”. plus one additional simulation for each parameter of interest—a daunting effort in the case of computationally demanding simulations with many parameters. Adjoint techniques allow one to extract gradient information from one base-case simulation plus an additional one or two carefully prepared simulations.* We demonstrate these techniques using the accelerator simulation code WARP, and we present our proof-of-concept results using several different FoMs as the basis for adjoint analyses of a simple beamline with multiple parameters.
Paper: WEP5304
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEP5304
About: Received: 18 May 2026 — Revised: 18 May 2026 — Issue date: 22 May 2026
WEP6003
Anomaly Detection and Denoising of Non-Gaussian Beams using 2D Image Reconstruction Techniques based on Deep Learning
2933
Automatic image reconstruction tools are essential in fields such as physics, astronomy, and biology. In particle accelerators like CERN’s LHC, they are particularly important for evaluating beam quality through beam distribution measurement as position, profile, and emittance. Traditional analysis tools no longer meet the accuracy and efficiency demands of future facilities. We developed a new AI/DL-based digital tool for 2D transverse phase-space distributions and scanner image denoising aimed at improving the accuracy of RMS emittance measurements. Our focus was to enhance beam halo characterization, ultimately contributing to reduce transport losses, and enabling more sustainable accelerator operations. Challenges are related to noisy experimental data, lack of ground-truth reference images, noise model, and limited training datasets. Our unsupervised deep convolutional neural network (DCNN) can denoise a single image using only itself as input thus greatly improving the accuracy of beam surface area estimation and hence the RMS emittance measurement.
Paper: WEP6003
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEP6003
About: Received: 07 May 2026 — Revised: 21 May 2026 — Issue date: 22 May 2026
WEP6007
Accelerator optimization for large parameter numbers embedded in the native FAIR control system environment
2941
The new accelerator complex, FAIR (the International Facility for Antiproton and Ion Research), will soon be commissioned to deliver ion beams using its injector and the GSI accelerator complex. In order to extend the operation of the GSI to include the FAIR and due to some ageing components, a new control system has been implemented. The time- and resource-efficient setup of complex ion beams, a long-standing challenge, has been addressed with a Java-based application called DeviceAutomator. This application handles different optimization routines based on modern machine learning technology. Apart from selecting the most suitable algorithm, challenges arise from data quality and the number of independent parameters. However, since the application is fully integrated into the FAIR control system, all operators in the control room can access and freely configure it without the need for coding. This contribution will describe the implementation and real-life testing of different algorithms: Bayesian, Genetic, and Random Walk. Using a long section of a low-energy ion transport beam line, it has been demonstrated that larger parameter spaces extending well beyond ten parameters present significant challenges for the Bayesian algorithm. However, the genetic optimization routine remains capable of identifying optimal values. It was also evident that a well-chosen optimization routine has the potential to make ion beam setup faster and less labor-intensive.
Paper: WEP6007
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEP6007
About: Received: 18 Apr 2026 — Revised: 21 May 2026 — Issue date: 22 May 2026
WEP6015
Bayesian Optimization of Longitudinal Phase Space in the MAX IV Linac
2957
Reaching design performance in modern particle accelerators is a challenge involving many tasks which are time-consuming and difficult to perform. It is always an advantage to be able to simplify high-level operational tasks and measurements through the assistance of optimization techniques. In this work we applied Bayesian optimization via the XOpt framework with the aim to simplify and enhance the operations in the MAX IV linac. The focus of this work has been longitudinal phase-space optimization using signals from a transverse deflector system. Further, a new approach in the optimization of longitudinal phase-space parameters with the use of virtual diagnostics has been developed and implemented.
Paper: WEP6015
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEP6015
About: Received: 15 Apr 2026 — Revised: 16 May 2026 — Issue date: 22 May 2026
WEP6018
High-Dimensional Bayesian Optimization for Sparse Objectives: an Application for Automated Beam Commissioning in the Low Energy Ion Ring at CERN
2969
Recent advances in high-dimensional Bayesian Optimization have opened the door to new tools for beam commissioning. At the CERN Low Energy Ion Ring (LEIR), several tuning challenges arise from the complex parameter space governing beam transfer and accumulation dynamics. In this paper we benchmark several state-of-the-art High Dimensional Bayesian Optimization methods to optimize the transfer from Linac3 to LEIR and maximize the accumulated beam inside the ring. We evaluate algorithms based on different strategies: trust region approaches (TuRBO), sparse axis-aligned subspace priors (SAASBO), nested embeddings for mixed spaces (Bounce), and length-scale-adapted priors in regular Bayesian Optimization. Our results demonstrate the relative strengths of each method in the context of particle accelerator optimization, where sample efficiency is critical, the objective function exhibits sparsity in relevant dimensions, and the parameter space contains both local and global structures. The benchmarking provides practical insights for selecting appropriate algorithms for beam commissioning tasks, considering factors such as convergence speed, computational overhead, and robustness to noisy observations.
Paper: WEP6018
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEP6018
About: Received: 13 May 2026 — Revised: 17 May 2026 — Issue date: 22 May 2026
WEP6023
Virtual beam position monitor for particle driven plasma wakefield accelerators
2981
Beam parameters at the interaction point (IP) of a particle driven wakefield accelerator (PWFA) are carefully controlled to optimize the output energy and beam quality. However, regardless of the parameters achieved, misalignments of beams at a PWFA IP has been shown to produce significant detrimental effects to the output energy and quality. Online monitoring of pointing stability, or beam jitter, at the IP is therefore essential to discern between beam quality optimisation needs and misalignment issues. However, it is not possible to use standard beam position monitors (BPMs) at these locations. Presented in this contribution is the demonstration of a proposed virtual beam position monitor (vBPM), applied to the IP of AWAKE. Upstream BPMs on the proton transfer line as used to infer the transverse position at the IP. A simulation study has been conducted to train a convolutional neural network (CNN) model to perform this inference. Dominant BPMs are highlighted, pointing towards areas of future optimisation to improve the proton beam jitter. Application to recent data collected at AWAKE is also presented, demonstrating the online reconstruction potential for future AWAKE runs.
Paper: WEP6023
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEP6023
About: Received: 12 May 2026 — Revised: 21 May 2026 — Issue date: 22 May 2026
WEP6031
Experimental Evaluation of a Digitizer Designed for ACCT Beam Current Transformers
2995
To integrate the signals of beam current transformers into accelerator control systems, particle accelerators require high-performance digitizers with optimized bandwidth, sampling rate, and dynamic range. They must be accurate and reliable. And they should be easy to deploy and operate. A specialized digitizer was developed to interface the Bergoz Instrumentation ACCT sensor and its analog front-end electronics to an accelerator control system. It allows waveform acquisition preserving the quality of the analog signal and controls the ACCT configuration. Communication is implemented over Ethernet through a simple command protocol, and an EPICS soft IOC is provided. The digitizer was tested with two ACCTs installed at the CHUV Oriatron Linac and a third at the METAS electron beamline. Results demonstrate improved signal-to-noise ratio, adaptability to multiple beam types, and simplified deployment compared to general-purpose digitizers.
Paper: WEP6031
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEP6031
About: Received: 11 May 2026 — Revised: 18 May 2026 — Accepted: 20 May 2026 — Issue date: 22 May 2026
WEP6039
Efficient Parameter Reconstruction from Gaussian Pulses using a GPU
3013
Pulse parameters such as height, width and peak time provide valuable information about the source. However, real-time evaluation is currently hardly possible for high repetition rates such as those as found in a synchrotron. In this contribution, we record the summed signal from beam position monitors at the Karlsruhe Research Accelerator (KARA) with the FPGA-based pulse digitizer KAPTURE-2 and demonstrate the efficient evaluation of Gaussian pulses. To enable real-time analysis of the acquired signals, these must be processed quickly and efficiently. Therefore, the computational workload is accelerated using a GPU, leveraging its parallel processing capabilities. In addition, an approach for parallelization on the CPU is evaluated to determine its effectiveness compared to GPU acceleration. This comparison also evaluates two methods for bunch reconstruction - QR decomposition and gradient-based least-squares minimization.
Paper: WEP6039
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEP6039
About: Received: 13 May 2026 — Revised: 22 May 2026 — Issue date: 22 May 2026
WEP6046
Upgrade of the Beam Loss Monitoring System for the Unilac Heavy Ion Linear Accelerator at GSI
3025
The beam-loss monitoring system of the UNILAC heavy-ion linear accelerator is based on measuring the beam current at multiple locations along the beamline. Signals from beam–current transformers are amplified, converted into pulse trains and counted within a defined time window. The system has proven to be robust and operationally safe. The ongoing upgrade aims to replace the current-to-frequency converters and the entire digital subsystem while preserving the established operational principle and the analog front-end. Most important reasons are ageing of the electronics, the need for improved scalability, flexibility and safety, and last but not least, alignment with the new GSI/FAIR controls architecture. The new system operates under the supervision of a System Control Unit (SCU), the standard front-end platform of the GSI/FAIR control system. It is controlled by the Front-End Software Architecture (FESA) and White Rabbit. Once configured, the FPGA-based hardware operates autonomously to ensure high reliability and fail-safe behaviour. Here we describe the system architecture, its modular hardware, firmware architecture and the software interface.
Paper: WEP6046
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEP6046
About: Received: 28 Mar 2026 — Revised: 22 Apr 2026 — Accepted: 15 May 2026 — Issue date: 22 May 2026
WEP6056
Novel Time-of-flight Measurement on a Short Base
3058
Time-of-flight (TOF) measurements are superior to other methods of measuring beam energy, since the quantity being measured is directly related to the velocity, and therefore the kinetic energy, of the particles. Conventional TOF systems use independent sensors in the beam transport system, each with a separate signal path to the measuring electronics. The difference in signal delay between the paths introduces an absolute error in the measured time. Increasing the flight time can help to reduce the impact of this error. For this reason, a flight path length of several metres is usually applied between the sensors. A novel method and device have been developed for accurate TOF measurements on a base as short as 20 cm. Two capacitive pickups in a common mechanical structure with an additional electrode are used. The signals from the probes are combined within the vacuum chamber, resulting in a single signal path from the sensor unit to the measuring electronics. Digital signal processing (DSP) is used to determine the distance between the pulses generated by a beam bunch on the probes. The construction details of the sensor unit and the applied digital signal processing (DSP) method, as well as the accuracy of the measurements achieved when operating with accelerated beams from a cyclotron, will be presented.
Paper: WEP6056
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEP6056
About: Received: 15 Apr 2026 — Revised: 17 May 2026 — Accepted: 18 May 2026 — Issue date: 22 May 2026
WEP6076
Off-Resonance Landau Cavity Field Probe Calibration
3084
The MAX IV storage rings use passive Landau cavities to achieve the desired bunch lengthening, and thus the desired performance in terms of beam lifetime and beam stability. It is therefore important to know the magnitude of the fields in these cavities during operation. Since the Landau cavities are passive, the calibration has to be done with beam present and is usually done at low current and at the cavity resonance. These calibrations are only as good as the modelled or measured shunt impedance of the cavity. Here, we will present an alternative off-resonance calibration scheme, which is performed at conditions more similar to standard operation during delivery to beam lines. This method is also less dependent on how accurately the shunt impedance can be determined.
Paper: WEP6076
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEP6076
About: Received: 12 May 2026 — Revised: 19 May 2026 — Issue date: 22 May 2026
WEP6079
A new analogue acquisition for the BPM of CERN PS
3096
The bunch-by-bunch and turn-by-turn beam trajectory measurement system of the CERN PS accelerator has been in operation for several years. To ensure long-term reliability, the consolidation of the analogue acquisition chain is foreseen during the upcoming LS3 long shutdown including a new architecture with improved performance, which is currently under test in the PS accelerator for final validation. The key element is a custom-designed high impedance head amplifier, replacing the 50Ω amplifier used by the current system, with the advantage of improving, at the same time, bandwidth, dynamic range and noise level. Increased dynamic range opens the possibility of measuring longer acceleration periods without gain switching and better resolution. Increased bandwidth allows the measurement of more beam configuration, in particular with shorter bunch to bunch distance. However, improved performances come at the expense of placing active electronics close to the beamline, in locations with significant radiation exposure, therefore requiring radiation-tolerant electronics. An overview of the PS trajectory system is presented, with the focus on the design of the new analogue acquisition, along with the preliminary bench and beam measurement results.
Paper: WEP6079
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEP6079
About: Received: 08 May 2026 — Revised: 20 May 2026 — Accepted: 20 May 2026 — Issue date: 22 May 2026
WEP6089
Feasibility of Non-invasive OSR Diagnostics in the AWAKE run-2C Injection Region
3120
AWAKE is CERN's proton-driven plasma wakefield acceleration experiment, currently advancing toward Run-2c to demonstrate the higher energy acceleration of electrons while maintaining the beam quality. A second electron beam (of 150 MeV energy), produced in a newly installed electron source, will be injected and accelerated to several GeVs while aiming to keep good emittance. Diagnostics are being upgraded for this geometrically constrained injection-region to enable single-shot characterization of that beam, among which this contribution evaluates the feasibility of optical synchrotron radiation (OSR) as a non-invasive real-time mean. OSR can provide shot-by-shot transverse position and profile information without disrupting beam delivery, critical for benchmarking beam-alignment and quality check. The prompt, non-invasive nature also makes it a candidate for future virtual diagnostic implementations, where online beam profiles could inform predictive models or feedback correction schemes. For performance optimizations the expected OSR photon flux, photon statistics, projected image quality are computed with realistic imaging optics and detector quantum efficiency. Results demonstrate that sufficient OSR signal can be extracted through this compact optical chain to achieve meaningful single-shot transverse profile measurements.
Paper: WEP6089
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEP6089
About: Received: 11 May 2026 — Revised: 21 May 2026 — Issue date: 22 May 2026
WEP6092
Transverse Phase Space Tomography at CLARA Using Generative Machine Learning
3132
CLARA is a high-brightness electron beam facility at STFC Daresbury Laboratory, aiming to deliver ultra-short electron bunches to a wide range of user experiments. CLARA has recently resumed operations after a major upgrade, and is currently undergoing beam commissioning at its nominal energy (250 MeV) and bunch charge (250 pC). During commissioning, studies of the transverse beam dynamics will be vital for optimizing the accelerator’s performance, and for validating the simulation models used during its design. Phase space tomography is a powerful technique for reconstructing a beam’s charge distribution in phase space; recent machine learning advances have led to faster, higher-resolution tomographic methods such as generative phase space reconstruction. In this contribution, we present detailed measurements of the 4D transverse phase space at CLARA. We validate the reconstructed phase spaces by using them to accurately predict the appearance of the electron beam for different beam optics configurations. Our results demonstrate methods that are now used for routine characterization of the CLARA beam, and represent the first emittance measurements at the accelerator’s design energy.
Paper: WEP6092
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEP6092
About: Received: 12 May 2026 — Revised: 17 May 2026 — Accepted: 22 May 2026 — Issue date: 22 May 2026
WEP6095
Python Based Control and Diagnostic Systems for AREAL Linear Accelerator
3140
AREAL linear accelerator constructed in Yerevan, Armenia, is designed to generate low-emittance, ultra-short electron beam pulses to enable advanced research in novel accelerator technologies, advanced coherent radiation sources, and dynamics of atomic and molecular processes. This paper presents an overview of the complex Python-based control system developed for the AREAL accelerator. It details the associated hardware components, software architecture, and auxiliary support applications. Additionally, future development plans for the control system and its integration with AREAL upgrading capabilities are discussed.
Paper: WEP6095
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEP6095
About: Received: 01 Apr 2026 — Revised: 17 May 2026 — Accepted: 17 May 2026 — Issue date: 22 May 2026
WEP6099
Status of accelerator automation in the community: classification, survey results, and the role of ai and machine learning
3144
The increasing complexity of particle accelerators and the growing demand for operational efficiency have intensified the focus on automation in accelerator control systems. However, there is still a lack of a common language to describe and compare the level of automation across different facilities. This article presents a generic classification scheme for accelerator automation, defining five distinct levels ranging from basic operational assistance to full autonomy. To assess the current state of automation in the accelerator community, a structured survey was conducted during the 14th Workshop on Accelerator Operations (WAO 2025). Responses from major laboratories indicate that more than one third of accelerators currently operate at the lowest level 1 (operational assistance), and no facility has yet reached full automation. However, projections show a clear trend toward higher levels within the next decade. Key drivers include optimization algorithms for autotuning, finite-state machines, and closed-loop feedback systems. This study provides both a conceptual framework and a snapshot of current implementation practices, supporting a shared understanding of accelerator automation across the community.
Paper: WEP6099
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEP6099
About: Received: 15 Apr 2026 — Revised: 19 May 2026 — Accepted: 20 May 2026 — Issue date: 22 May 2026
WEP6100
Commissioning of the FAIR Control Centre
3148
The FAIR Control Centre (FCC) has been purpose-built on the GSI campus to meet the complex operational demands of the FAIR/GSI large scale accelerator facility. It hosts the Main Control Room (MCR), seminar and meeting rooms of various sizes, offices, and dedicated technical rooms. The 640 m² MCR is an open, collaborative workspace for accelerator experts, experiment teams, and technical staff. It offers a 24/7 ergonomic environment with ad-vanced acoustic and climate control, height-adjustable consoles, and a water-cooled IT infrastructure. In addi-tion to the console displays, the fully digital MCR fea-tures ca. 110 m² of high-resolution LED overview dis-plays for system-level visualization. Construction of the MCR was completed in November 2025. Console installation began on December 8th, fol-lowed by IT installation and commissioning in early 2026. Initial operation of the first consoles was per-formed in late February, with full MCR operation target-ed for June 2026. The GSI accelerators will be controlled from the FCC for the beam time starting in September. We report on the FCC key features and the project sta-tus on its path to completion, with an emphasis on com-missioning.
Paper: WEP6100
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEP6100
About: Received: 18 Apr 2026 — Revised: 17 May 2026 — Issue date: 22 May 2026
WEP6118
Upgrade of the LHC Low-Level RF Beam-Control for the Digital Frequency Distribution over White-Rabbit
3199
In preparation for the High-Luminosity LHC (HL-LHC) era, a significant upgrade to the LHC Low-Level RF (LLRF) Beam-Control system is being implemented. The installation of crab cavities during Long Shutdown 3 (LS3, 2026-29), together with the obsolescence of existing components, necessitates a modernization of the LHC LLRF architecture. The upgraded Beam-Control system - based on MicroTCA and VME hardware - replaces the frequency program and reconstructs a digital master RF. These frequencies are transmitted over a White-Rabbit (WR) network in the form of Frequency Tuning Words (FTW) to maintain synchronization among the distributed RF devices. This approach enables a scalable RF distribution infrastructure across the accelerator complex and experiments, with improved phase stability and reduced noise. This paper presents the motivation and design of the upgraded system, including the method used to achieve robust phase synchronization over WR. Finally, it shows results obtained from a dedicated test with beam acceleration in the LHC.
Paper: WEP6118
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEP6118
About: Received: 28 Apr 2026 — Revised: 18 May 2026 — Issue date: 22 May 2026
WEP6124
Radiation Protection for Laser–Plasma Accelerator Facilities at DESY
3219
DESY draws on more than six decades of experience in the development, operation, and radiation protection of large-scale user facilities such as PETRA III, FLASH, and the European XFEL. In parallel, the investigation of novel accelerator technologies for future applications has become a key focus. Laser-plasma acceleration (LPA) offers the potential for highly compact, high-gradient sources, as demonstrated by the LUX, KALDERA, and FORWARD facilities at DESY. However, LPA systems introduce new challenges for radiation protection due to broadband emission spectra and the interplay of high-power lasers with plasma-generated secondary radiation fields. This contribution presents the radiation-protection concept for LPA facilities at DESY, covering shielding simulations and designs with a focus on the differences com-pared to conventional electron accelerators. Finally, operational experience from commissioning the KALDERA LPA and further development stages is discussed, illustrating practical implementation.
Paper: WEP6124
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEP6124
About: Received: 12 May 2026 — Revised: 17 May 2026 — Accepted: 17 May 2026 — Issue date: 22 May 2026
WEP6127
GSI Operation Statistics in the FAIR Construction Phase (2012 - 2025): Trends, Failures and Lessons Learned
3222
We present operational statistics for the GSI accelerator complex during the FAIR construction phase from 2012 to 2025, covering UNILAC, SIS18, ESR, HEST and CRYRING@ESR. The analysis is based on beam-time schedules, availability monitoring, and fault annotations from the Operator Logbook (OLOG). During the last five years, failure entries were systematically reviewed and reclassified to ensure consistent data quality and enable reliable long-term trend evaluation. The main performance indicator discussed is accelerator availability, determined from scheduled operation periods and fault-related downtimes. The evaluated data were used as a quantitative input in the recent POF-5 evaluation process (2028-2034), where they clearly supported refurbishment and consolidation needs at GSI. A technical roadmap was established this year to prioritize these measures according to their impact on stable beam delivery towards FAIR accelerators.
Paper: WEP6127
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEP6127
About: Received: 15 Apr 2026 — Revised: 17 May 2026 — Issue date: 22 May 2026
WEP6130
Asset Management Workflows for cSTART using Snipe-IT
3226
For the cSTART project the Institute for Beam Physics and Technology (IBPT) at the Karlsruhe Institute of Technology (KIT) introduced with Snipe-IT a new system to manage all accelerator related components. As the new components arrive, one of the first step is entering them into the asset database, which creates a unique identifier. This identifier is then also used during the quality inspection process as the main reference. The asset-to-asset associations possible with Snipe-IT provide a simple and efficient method for structuring the components in cabinets and along the storage ring. The flexible custom fields allow to track references to other data sources, which provide the more technical information such as CAD drawings, cable routing and device documentation. In addition, it also allows to track component specific information. This contribution describes the established workflows, status and lessons learned using a generic IT asset management system for accelerator component management.
Paper: WEP6130
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEP6130
About: Received: 12 May 2026 — Revised: 18 May 2026 — Issue date: 22 May 2026
WEP6144
Modification of the transverse electron bunch profile with spatial light modulator at FLUTE
3247
The linac-based test facility FLUTE (Ferninfrarot Linac- Und Test-Experiment) at the Karlsruhe Institute of Technology (KIT) was designed as a test bench for accelerator technologies with a broad range of beam parameters. The electron bunches are generated in a UV photo-injector which offers laser pulse shaping as control of the beam parameters. The imprint of a transverse laser profile modulated by an spatial light modulator (SLM) onto the electron bunch was demonstrated at the low energy section of FLUTE. The addition of the linear acceleration structure and bunch compressor section, as well as the upgrade of the RF system, enables experiments with short-pulse electron bunches up to 90 MeV. For this contribution, the SLM was used to recreate the modified electron bunch profile and we present the observed characteristics after passing the traveling-wave RF structure and magnetic chicane.
Paper: WEP6144
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEP6144
About: Received: 12 May 2026 — Revised: 19 May 2026 — Issue date: 22 May 2026
WEP6145
The MYRRHA phase 1 MTCA.4-based LLRF system
3251
The first 100 MeV stage of the MYRRHA superconducting RF linear accelerator is under construction in Mol, Belgium. The machine produce an instantaneous proton beam current of 4 mA and represents the first step toward the construction of the MYRRHA Accelerator-Driven System (ADS). Such a machine presents several technical challenges for the control of its RF cavities. First, the required field stability is ≤ 0.1% in amplitude and ≤ 0.1° in phase to avoid excessive beam losses. The high loaded quality factor (QL = 2.3×10⁶) and the need to modulate the beam at 250 Hz require sophisticated field- and detuning-control techniques to keep RF consumption and stability within specifications. Finally, since the maximum allowed beam-trip duration is less than 3 seconds, real-time fault detection and recovery techniques must be implemented in the Low-Level RF (LLRF) controller. To meet these stringent requirements, the MTCA.4 standard and the DAMC-DS5014DR direct-sampling AMC were chosen. In this proceeding, the LLRF control strategy foreseen for the MYRRHA phase 1 will be presented. The current status of the firmware, software, and analog front-end will also be discussed.
Paper: WEP6145
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEP6145
About: Received: 15 Apr 2026 — Revised: 03 May 2026 — Issue date: 22 May 2026
WEP6146
RF system status for PERLE
3255
The PERLE project consists of a 5MW at 250 MeV Energy Recovery Linac (ERL) demonstrator, with the accelerating cavities operating at 801.58MHz and 2K. The superconducting cavities needs to be regulated in terms of amplitude, phase and frequency due to perturbations such as microphonics, Lorentz forces and Beam loading. New developments dedicated to PERLE are in progress in order to achieve the performances. Firstly, a Distributed Master Oscillator (DMO), White Rabbit (WR) protocol based allowing to distribute a reference and to generate locally the synchronized RF signals and clocks needed. It is also associated to a timing system using the same WR enhanced hardware (IDROGEN Board) to produce the synchronized timing triggers and gates for all the machine. In addition, a new C&C board of the Frequency tuning system is developing to increase the ecosystem around the IDROGEN board. The LLRF Feedback system is also MTCA based using Off the shelf bards from IOXOS technologies, associated to a RF power Solid state amplifier prototype from JEMA FRANCE upgradable form 8.8kW to 60kW. An overview and a status of these systems and their implantations will be presented with some outlooks.
Paper: WEP6146
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEP6146
About: Received: 12 May 2026 — Revised: 18 May 2026 — Accepted: 18 May 2026 — Issue date: 22 May 2026
WEP6149
Narrowband Active Noise Control for Continuous Wave Operation of TESLA Cavities
3262
TESLA 9-cell elliptical cavities are used in the accelerators of the European XFEL and LCLS-II. The high duty cycle upgrade study for EuXFEL and the LCLS-II-HE program target loaded Quality factors of 6e7 and beyond, leading to RF cavity half bandwidths below 11Hz. Stable operation in these conditions heavily relies on active RF resonance control, as required RF drive power to maintain amplitude and phase lock surpasses amplifier max ratings if detuning is not compensated. To counteract mechanical vibrations, e.g. introduced by rotational machines in the proximity of the accelerating modules, a dedicated narrowband active noise control algorithm was introduced in previous work. This proceeding presents CPU based implementations and latest test results obtained at the Cryomodule Test Bench (CMTB) at DESY and LCLS-II at SLAC, where the stable operation gradient of a cavity could be increased from 9 to 15MV/m without violating RF control limits.
Paper: WEP6149
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEP6149
About: Received: 10 May 2026 — Revised: 20 May 2026 — Issue date: 22 May 2026
WEP6154
Benchmarking beam dynamics simulations for the MYRRHA Phase 1 accelerator
3273
At the Nuclear Research Center SCK CEN in Belgium, the first phase of the MYRRHA project (an accelerator driven system) is under construction. Included in MYRRHA Phase 1 are a 17 MeV normal conducting injector linac (RFQ + CH cavities) and a super conducting linac (60 single spoke cavities), providing a CW proton beam of 4 mA at 100 MeV. In this contribution, beam dynamics simulations of the MYRRHA Phase 1 accelerator are compared for four different beam dynamics codes: TRACEWIN, pyORBIT3, DYNAC and pyACCEL. The beam simulation results for a reference case are compared, as well as the computing times. Furthermore, approximations which can be made to speed up the computation times are discussed. These comparisons are made in view of a future on-line deployment of a simulation tool during beam commissioning.
Paper: WEP6154
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEP6154
About: Received: 12 May 2026 — Revised: 19 May 2026 — Accepted: 20 May 2026 — Issue date: 22 May 2026
WEP6156
Surrogate models for the European XFEL operation
3277
Numerical beam dynamics simulation codes are essential for designing and studying particle accelerators, but their computational cost can make them unsuitable for online use and predictions during operations. The use of machine learning-based surrogate models can significantly reduce the required computational time whilst still providing an accurate prediction of the beam properties. In this paper, we present the first results on the training of surrogate models for the prediction of the longitudinal phase space (LPS) at the European XFEL. Finally, we discuss the potential application of such models in the development of a virtual diagnostic tool for use in the European XFEL control room as well as a fast estimator for the final LPS based on the user-provided compression parameters.
Paper: WEP6156
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEP6156
About: Received: 13 May 2026 — Revised: 20 May 2026 — Issue date: 22 May 2026
WEP6158
Turning Logbook Data into Operational Insight with a new Statistics Service at GSI and FAIR
3285
It is common practice during accelerator operation to continuously document all relevant machine states and activities. At GSI Helmholtz-Center for Heavy Ion Research, this is done using an electronic logbook (OLOG) developed in-house and adapted to the specific requirements of accelerator operations, allowing shift crews to record failure events, setup times, and other important information in high detail. A new service, currently under development, aims to simplify the on-demand access to relevant statistics and is being prepared to include data from the Facility of Antiproton and Ion Research (FAIR) as its operations gradually commence in the upcoming beamtimes. This service is built as two layers, a backend layer communicating with the database to pull entries from the logbook system and to calculate statistics from them, and a frontend layer handling user requests as well as providing a graphical depiction of these statistics and their raw data. This report presents the current logbook system used at GSI and FAIR and introduces the new statistics service to be implemented as an assessment tool.
Paper: WEP6158
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEP6158
About: Received: 15 Apr 2026 — Revised: 14 May 2026 — Accepted: 15 May 2026 — Issue date: 22 May 2026
WEP6164
Providing reproducibility and accessibility of research software development for accelerator physics at KARA
3293
Modern accelerator facilities generate heterogeneous data from diagnostics, sensors and simulations, making it difficult to manage, reproduce, and contextualize results as software and models evolve. While FAIR principles (Findable, Accessible, Interoperable, Reusable) are increasingly applied to research data, the iterative development of scientific software, with its rich metadata and benchmarks, rarely follows them. Small changes in compiler flags, dependencies, or hardware can alter outcomes, yet are often undocumented. We address this gap with BenchTune, a telemetry and reporting layer in C++ and Python that interfaces with the Kadi4Mat (Kadi) virtual research environment. BenchTune records metadata for each algorithm run, compiler information, parameters, metrics and stores it in Kadi as portable, traceable research artifacts. A project-view plugin in Kadi visualizes the evolution of a research project, linking code versions, datasets, and benchmark runs into coherent workflows. As a result, our contribution provides a reproducible framework that supports FAIR principles for research data, enabling sustainable and collaborative research in accelerator physics and beyond.
Paper: WEP6164
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEP6164
About: Received: 12 May 2026 — Revised: 17 May 2026 — Issue date: 22 May 2026
WEP6165
Generic Python Algorithm Plugin for the EPICS Area Detector Framework
3297
Area Detector is widely used in accelerator and observatory control systems to build data processing pipelines for images and waveforms, but adding new processing stages normally requires specialized C++ development. This slows prototyping and limits access to modern analysis tools that are predominantly available in Python. We present a new Area Detector plugin that executes user-defined Python algorithms directly on acquired images and their metadata. The plugin integrates advanced scientific libraries and machine learning toolkits, supports GPU acceleration, and enables parallel execution through multi-stage pipelines or Python multiprocessing. Algorithms can be updated without recompiling the IOC, allowing rapid iteration during operations. An automatically generated GUI exposes configurable parameters to operators. The approach is being evaluated on ESA’s NEOSTED telescope system, where Python-based routines are used for telescope autofocusing.
Paper: WEP6165
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEP6165
About: Received: 13 May 2026 — Revised: 18 May 2026 — Issue date: 22 May 2026
WEP6170
Pipelines: A Node-Based Editor for Streamlined Optimisation Prototyping in the Control Room
3300
Development shifts on accelerators are usually time-constrained and infrequent. Meanwhile, control room PCs are not designed for scrappy R\&D, and maintaining multiple workflows with python scripts is prone to error. GUI apps have been successfully deployed and used in the past to perform optimisation at accelerator facilities. However, bookkeeping can become difficult in complex tasks. Furthermore, support is missing for pre-optimisation steps such as response matrix measurements used in Slow Orbit Feedback (SOFB) machine learning algorithms. A PySide node-based visual editor has been developed and tested in the Diamond control room. A logical heirarchy of blocks define processes to perform and an inspector window allows the user to fine-tune blocks to their needs. Separate processes are spawned when compute or time-intensive blocks are run, keeping the main UI thread responsive. An optimisation problem is tackled using the app to demonstrate its usefulness.
Paper: WEP6170
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEP6170
About: Received: 12 May 2026 — Revised: 18 May 2026 — Issue date: 22 May 2026
WEP6303
Efficient Five-dimensional Beam Sigma Matrix Determination Using Differentiable Simulation
3312
Precise reconstruction of the beam sigma matrix is critical for transport-line modeling and injection optimization. Our earlier work demonstrated that the differentiable simulation framework Cheetah enables gradient-based recovery of the 5×5 transverse sigma matrix at the APS-U BTS transport line using quadrupole scans. In this paper, we extend the method to improve efficiency and robustness. We introduce a generalized formulation that incorporates multi-screen measurements, providing increased stability in realistic lattice configurations. The differentiable-tracking approach yields physically consistent reconstructions while remaining computationally scalable. These developments form a practical framework for sigma-matrix determination in complex transport lines and support future real-time model calibration and tuning at the APS-U and similar facilities.
Paper: WEP6303
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEP6303
About: Received: 13 May 2026 — Revised: 17 May 2026 — Accepted: 17 May 2026 — Issue date: 22 May 2026
WEP6603
LLRF Prototype Design for the 1.3 GHz Cryomodule of the Shenzhen Superconducting Soft X-ray FEL
3324
This paper presents the design and preliminary test results of a Low-Level Radio Frequency (LLRF) prototype system developed for the 1.3 GHz standard cryomodule of the Shenzhen Superconducting Soft X-ray Free Electron Laser (S3FEL). The system is implemented within an MTCA.4 platform, integrating eight RF controller boards for superconducting cavity field acquisition and microwave excitation control to stabilize the RF field and ensure steady electron beam acceleration, alongside two tuner controller boards for driving four coupler motors, four cavity tuner motors, and eight piezoelectric actuators (PZTs). A high-speed peer-to-peer (P2P) backplane bus enables real-time communication between RF and tuner control boards. The report outlines the hardware architecture of this modular LLRF system and discusses initial functional and performance tests, demonstrating its suitability for meeting the precise stability requirements of the S3FEL project.
Paper: WEP6603
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEP6603
About: Received: 13 May 2026 — Revised: 20 May 2026 — Issue date: 22 May 2026
WEV1301
Accelerator Design Educational Primer – Conceptualizing and Optimizing the Hybrid LHeC-like Electron-Ion Collider Design
3351
The Electron-Ion Collider (EIC) Mission Need requires √s = 20–100 GeV (upgradable to 140 GeV) and luminosity 10³³–10³⁴ cm⁻² s⁻¹. The current ring-ring baseline achieves the full scope, including ~10³⁴ cm⁻² s⁻¹ across all energies. However, when the design is re-optimized for the lower boundary — accepting ~10³³ cm⁻² s⁻¹ and prioritizing cost — an alternative configuration emerges as more advantageous: a hybrid LHeC-like electron accelerator using multi-pass energy recovery linacs (ERL). This solution reduces electron-beam power by roughly an order of magnitude, yielding nearly a factor of two reduction in total project cost compared with the present baseline while still satisfying the minimum physics requirements. The study performs parametric cost and performance modeling, augmented by AI-driven optimization, to explore this design space. Serving primarily as an educational exercise for the next generation of accelerator physicists and engineers, the paper demonstrates modern design methods: rapid parametric scans, cost-driven optimization, and integration of AI tools. It examines technical feasibility, identifies critical R&D (high-current ERL operation, beam–beam effects, synchronization, etc.), and discusses how such re-optimization studies can be used to train designers in an era when artificial intelligence dramatically expands exploration of complex accelerator parameter spaces.
Paper: WEV1301
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEV1301
About: Received: 12 May 2026 — Revised: 19 May 2026 — Accepted: 22 May 2026 — Issue date: 22 May 2026
WEV4302
FIRST EXPERIMENTAL DEMONSTRATION OF USING A CRAB-CROSSING COLLISION SCHEME FOR EFFICIENT LASER-TO-ION BEAM INTERACTION
3363
Lasers are used in many applications with H⁻ beams, including laser charge exchange, laser wire scanners, and laser temporal pulse patterning. In these applications, the H⁻ beams exhibit a wide range of bunch lengths that depend on the focusing of the RF cavities, the energy spread of the beam, and space charge forces. Achieving the required laser pulse length for complete overlap with the H⁻ beam can be challenging in scenarios where available laser power is constrained. A crab-crossing scheme was proposed to achieve efficient overlap of a short laser pulse with an arbitrarily long H⁻ beam pulse. This presentation reports the first experimental demonstration of this technique, which increases the efficiency of laser-to-ion beam interaction in a laser stripping experiment at SNS by 50%.
Paper: WEV4302
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEV4302
About: Received: 14 May 2026 — Revised: 18 May 2026 — Accepted: 19 May 2026 — Issue date: 22 May 2026
WEV5002
Bunch lengthening with double- and triple-rf systems for MAX4U
3367
MAX IV is engaged in the design of a major upgrade to its 3 GeV ring, called MAX 4U. The upgrade aims at an improvement in light source performance to maintain MAXIV’s competitive edge beyond the end of this decade. In this contribution, we report on the studies of the performance of double- and triple-rf systems for bunch lengthening with MAX4U parameters. The stationary bunch profiles and longitudinal instabilities thresholds were evaluated with semi-analytical methods and benchmarked with macroparticle tracking simulations for different settings of the harmonic rf cavities.
Paper: WEV5002
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEV5002
About: Received: 12 May 2026 — Revised: 21 May 2026 — Accepted: 22 May 2026 — Issue date: 22 May 2026
WEV6003
Moonlight on the Serengeti: Casting (Digital) Shadows with SIMBA, PUMBA, LAURA and Friends
3379
Digital shadows offer a methodology for bridging physical particle accelerators with their virtual counterparts, enabling predictive modelling, automated control, and improvements in facility design and implementation. A digital shadow for the CLARA accelerator is being developed, integrating two complementary tools: LAURA, an ontology-driven description language for particle accelerator lattices; and SIMBA, a simulation framework that utilises LAURA-defined models to perform start-to-end particle tracking using multiple tracking codes. Together, LAURA and SIMBA form the simulation backbone of a digital shadow, providing a consistent and extensible representation of the accelerator. This architecture is further augmented by pyCATAP, a controls middle layer that interfaces with accelerator control systems, PUMBA, a procedural automation framework for running complex operational tasks and standardising I/O data structures, and SARABI, a framework for generating soft EPICS IOCs from a LAURA lattice.
Paper: WEV6003
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-WEV6003
About: Received: 11 May 2026 — Revised: 20 May 2026 — Accepted: 22 May 2026 — Issue date: 22 May 2026
THO3T02
Terahertz techniques in the advanced accelerator landscape
3397
Terahertz (THz)-frequency particle acceleration provides a natural “bridge” between conventional electronic-based (radio-frequency RF) and novel photonic-based (laser plasma wakefields LWFA) drivers, offering stable, high-frequency, high-gradient fields for compact interactions, coupled with direct femtosecond-scale synchronization to the THz drive laser*. These unique properties ideally position THz technologies to enhance the capabilities of existing RF infrastructure, while also solving key challenges to help drive the transition towards compact high-gradient laser-based accelerator applications. As a key example, I will present our latest experimental results and simulations demonstrating efficient THz-driven chirping and energy modulation of relativistic electron bunches, enabling the compression of ultrashort bunches and picosecond-spaced bunch trains with femtosecond-scale "temporal-locking" to the THz drive laser**. These results unlock a potential array of advanced electron-laser applications requiring precise synchronization at the shortest timescales, such as pump-probe experiments with FEL light, single-shot ultrafast electron diffraction, electron-laser collisions to probe strong-field quantum electrodynamics and for high-quality LWFA through controlled external injection. On the latter I will discuss our work towards achieving this goal, in addition to highlighting the other unique roles THz technologies can play in the future advanced accelerator landscape.
Paper: THO3T02
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-THO3T02
About: Received: 13 May 2026 — Revised: 20 May 2026 — Accepted: 22 May 2026 — Issue date: 22 May 2026
THO4M01
Update on the FAIR machine installation status
3401
The accelerator complex for the Facility for Antiproton and Ion Research (FAIR) is currently being built in Darmstadt, Germany. After the arrival of the cold box for the central cryogenic facility (CRYO2) in winter 2023, the installation of the accelerator components in the machine and supply tunnels started early 2024. Meanwhile the installation has moved forward. CRYO2 has been handed over to the commissioning team and the commissioning is in progress. The accelerator installation is ongoing in all parts of the beamlines of the High Energy Beam Transfer Lines (HEBT), the Super Fragment Separator (SFRS) and the Heavy Ion Synchrotron (SIS100). In parallel, the installation plans for the experiments (NUSTAR and CBM) are being developed and installation preparations are taking place. In this paper the status and challenges of the machine installation in those areas are presented and an outlook for the next steps towards realisation of the project phases for Early and First Science is given.
Paper: THO4M01
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-THO4M01
About: Received: 13 May 2026 — Revised: 20 May 2026 — Issue date: 22 May 2026
THO4M02
Beam commissioning and upgrade progress for the CSNS-II RCS
3406
For the China Spallation Neutron Source (CSNS), the rapid cycling synchrotron (RCS) accumulates and accelerates the injection beam to the design energy of 1.6 GeV and then extracts the high energy beam to the target. In this paper, firstly, the beam commissioning of the RCS have been comprehensively studied, including new injection system commissioning, longitudinal dynamics optimization, beam instability mitigation, tune optimization, closed orbit correction, beam loss optimization, bayesian optimization and so on. In order to meet the requirements of beam power increase and stable operation of the CSNS accelerator, the RCS beam losses from different sources are studied and optimized. With the aid of weekly radiation dose measurement, the hot spots of the RCS are studied in depth to explore the causes and find the solutions. Secondly, as the second phase of the CSNS, CSNS-II will achieve a beam power on the target of 500 kW. The injection energy of CSNS-II will be increased from 80 MeV to 300 MeV and the injection beam power will be increased about 20 times. In this paper, the challenges and solutions of the CSNS-II RCS will be introduced and the upgrade of the RCS will be studied. Based on the detailed simulation results and beam experimental results, the upgrade schemes of the critical systems for the CSNS RCS has been proven feasible.
Paper: THO4M02
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-THO4M02
About: Received: 13 May 2026 — Revised: 22 May 2026 — Issue date: 22 May 2026
TUI4M00
Accelerator Research for Proton Therapy
3410
Proton therapy is a powerful tool in the fight against cancer. The number of accelerators has increased tremendously over the last years. Patients are treated now at over 125 facilities world-wide, which is an excellent example of an extremely successful technology transfer from fundamental research to healthcare. Depending on the tumour species, local tumour control can reach very high levels, e.g. more than 96% for uveal melanoma. To minimize side effects and maintain tumour control, new treatment modalities like FLASH or Minibeams are investigated. For FLASH, dose rates should be higher than 40 Gy/s with treatment times below 0.5 s. Minibeams aim for spatial fractionation of the beam. Experiments on cells, organoids and animals have been promising. These new irradiation forms create challenges for the existing and future accelerators: Developments in beam delivery, beam adaptation, and dosimetry are necessary. This paper describes changes on control system, beam shutters, and beam scattering systems which allow now irradiation times of 10 ms with a precision in dosimetry of better than 3% for a Spread-Out Bragg Peak at HZB. The set-up of a target station for minibeams will be presented.
Paper: TUI4M00
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-TUI4M00
About: Received: 07 May 2026 — Revised: 18 May 2026 — Accepted: 21 May 2026 — Issue date: 22 May 2026
THO6T02
Development of a new ultraslow muon beam diagnostic system for the J-PARC muon g-2/EDM experiment
3426
The E34 experiment at J-PARC MLF aims to precisely measure the positive muon's anomalous magnetic moment and electric dipole moment. Two technical challenges are critical. First, the ultraslow muon source (from muon cooling) must achieve its target intensity ($10^6 \mu^+/\text{sec}$) and low-emittance ($\epsilon_{x, \text{rms,normalized}}: \sim 0.3 \pi [\text{mm}\cdot\text{mrad}], \epsilon_{y, \text{rms,normalized}}: \sim 0.1 \pi [\text{mm}\cdot\text{mrad}]$). Second, the low-energy (5.7 keV) beam is highly sensitive to ambient magnetic fields and must be matched to the accelerator's acceptance with <10% accuracy, requiring active trajectory correction while preventing emittance growth. To verify these conditions—muon source property and beam matching—we developed a new ultraslow muon beam diagnostic system. In this system, the control section uses electrode pairs to actively correct the beam trajectory, which is sensitive to ambient fields. The transport section removes background particles (using an electrostatic mirror and bending magnet) and focuses the beam (using electrostatic quadrupoles). The measurement section uses the Q-scan method to measure the beam property. Simulations were used to optimize the system for 100% transport efficiency and <10% emittance measurement accuracy. Subsequent commissioning confirmed the system is ready for the quality evaluation of the beam in the new experimental area. This poster will discuss the simulation and commissioning results.
Paper: THO6T02
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-THO6T02
About: Received: 13 May 2026 — Revised: 22 May 2026 — Accepted: 22 May 2026 — Issue date: 22 May 2026
THP2009
ALBA II accelerator upgrade project status
3434
ALBA is working on the upgrade project that shall transform the actual storage ring, in operation since 2012, into a 4th generation light source, in which the soft X-rays part of the spectrum shall be diffraction limited. The project was launched in 2021 with an R&D budget to build prototypes of the more critical components. The storage ring upgrade is based on a MBA lattice which has to comply with several constraints imposed by the decision of maintaining the same circumference (269m), the same number of cells (16), the same beam energy (3GeV), and as many of the source points as possible unperturbed. At present, the lattice optimization, iterating with the technical constraints of space and performance, is ongoing. This paper presents the situation of the project, with the present proposed lattice and equipment design; the status of the prototyping of magnets, pulsed elements. vacuum chambers, buttons BPMs, and girders; the proposed RF system with fundamental and harmonics cavities; and the general context of the upgrade.
Paper: THP2009
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-THP2009
About: Received: 13 May 2026 — Revised: 19 May 2026 — Accepted: 21 May 2026 — Issue date: 22 May 2026
THP2023
The cool copper operation linac demonstrator project
3471
The ESRF long term strategy for the injectors upgrade includes the possibility of a full energy 6GeV linac. This linac is supposed to fit on the ESRF site leading to a maximum footprint of ~130m. High gradient accelerating structure technology from SLAC* was selected as the enabling technology to realize such a compact injector linac. The use of a phogun and pulse compression would imply small 6D beam phase space at extraction and a sensible cost reduction. The paper will introduce the Cool copper Operation Linac Demonstrator (COLD) project that has started at ESRF with the objective to realize a pre-injector linac and test all the enabling technologies for an high gradient cost effective 6GeV linac.
Paper: THP2023
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-THP2023
About: Received: 28 Apr 2026 — Revised: 30 Apr 2026 — Accepted: 15 May 2026 — Issue date: 22 May 2026
THP2028
SOLEIL 2025 Operational Status
3483
SOLEIL, the French 2.75 GeV third-generation synchrotron light source, continues to operate as a high-performance research infrastructure supporting both academic and industrial communities. This contribution reviews the 2025 operational achievements, with emphasis on accelerator stability, availability, and the delivery of reliable photon beams to 29 beamlines. Key performance indicators and operational trends are presented, together with an analysis of major events and the mitigation strategies implemented to strengthen machine robustness. Significant progress in addressing component obsolescence is reported, including advances in BPM electronics, RF systems, and the global control-system upgrade. Updates on the LINAC modernization programme are provided, along with the use of the current SOLEIL accelerator as an integrated test platform to validate critical technologies for the forthcoming facility upgrade. Preparatory activities for SOLEIL II are outlined, including a progress report for bunch-per-bunch transverse feedback system, development and preparation to the qualification of new 352 MHz low-HOM RF cavities, the 1.4 GHz fourth-harmonic system, and upgraded control architectures, highlighting the technical readiness for the next-generation machine.
Paper: THP2028
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-THP2028
About: Received: 20 May 2026 — Revised: 20 May 2026 — Issue date: 22 May 2026
THP2033
Designing radiation protection for PETRA IV: concepts and challenges
3495
DESY, an international accelerator research center, builds on over six decades of experience in the design, construction, and operation of world-class user facilities. The upcoming PETRA IV project represents a major upgrade from PETRA III into a 4th generation light source, involving a complete rebuild of the accelerator and a full redesign of its radiation-protection systems. This upgrade requires advanced shielding calculations and designs for both the accelerator and new buildings, in particular the new user hall, a state-of-the-art personnel safety system, and safety processes fully aligned with current laws and standards. In addition, advanced radiation-detection systems are being developed to ensure continuous monitoring of beam operation. This contribution provides an overview of the initial concepts for PETRA IV’s radiation-protection strategy, highlighting key design challenges, safety innovations, and implementation considerations for a modern, high-performance synchrotron facility.
Paper: THP2033
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-THP2033
About: Received: 05 May 2026 — Revised: 18 May 2026 — Accepted: 20 May 2026 — Issue date: 22 May 2026
THP2039
Elettra 2.0 - The new frontier of synchrotron radiation
3515
With the definitive shutdown of Elettra on July 2, 2025, a new chapter opens for scientific and technological research in Trieste. After thirty-two years of activity with excellent results, Elettra, Italy’s 3rd generation light source is handing over the baton to the Elettra 2.0 project, a fourth-generation light source based on an ultra-low emittance and high transverse coherence storage ring, designed to address the challenges of contemporary science: three-dimensional imaging, ultra-high-resolution spectroscopies (such as XAS, XPS, and RIXS), and time-resolved techniques on the picosecond scale. In the paper the project is presented including information on the old machine removal, the present installation progress as well as the future plans on short pulses and energy sustainability.
Paper: THP2039
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-THP2039
About: Received: 15 Apr 2026 — Revised: 17 May 2026 — Accepted: 18 May 2026 — Issue date: 22 May 2026
THP2048
Dismantle, assembly ant installation plans for the ALBA II upgrade
3534
The 3.0 GeV ALBA Synchrotron Light Source, in user operation since 2012, is preparing for an upgrade aimed at increasing the brightness and coherence fraction of the delivered X-ray beam. The Storage Ring will be completely renewed while preserving the Insertion Device source points, the orbit length and the electron beam energy; the current injector will remain in use. The “dark period” is planned for 2030-2031. In this contribution, we present part of the work being done to prepare the upgrade: the implementation program. The scope of this project covers the storage of equipment before and after assembly, the logistics to perform all the required movements, the establishment of testing areas for characterizing new components, the assembly zones for vacuum arcs, girders and magnets, and the disposal management of the dismantled equipment. It also includes the coordination of the removal, installation and test activities in both the Tunnel and the Service Area.
Paper: THP2048
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-THP2048
About: Received: 11 May 2026 — Revised: 18 May 2026 — Accepted: 18 May 2026 — Issue date: 22 May 2026
THP2071
Sustainable data transformation strategies for particle and field data in modeling free-electron lasers
3588
Scientific data is commonly stored in formats such as CSV for small to medium datasets, HDF5 for complex hierarchical structures, and NetCDF for gridded and temporal variables. These formats provide robust mechanisms for structured storage, preparing hierarchical or multidimensional data for machine learning (ML) models and GPU-accelerated computation. However, often they incur substantial transformation overhead. Recent studies have demonstrated the promise of tailored data-transformation and encoding approaches in scientific domains. In particular, convolutional autoencoder–based compression of 3D particle-tracking data can achieve significant reductions in post-processing as well as storage requirements while keeping the essential spatial features for downstream workflows. This work discusses the potential of domain-specific encoding strategies for interfacing particle and field data across different simulation tools, with the goal of enhancing the scalability and integration of scientific data into more sustainable workflows and future machine learning pipelines.
Paper: THP2071
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-THP2071
About: Received: 19 May 2026 — Revised: 21 May 2026 — Issue date: 22 May 2026
THP2086
RF system upgrade of ELSA electron linac at CEA
3610
ELSA electron linear accelerator, operated at CEA/DAM for over three decades, is currently undergoing a major upgrade of its RF accelerating structures with the objective of enhancing operational reliability, availability, and performance. The first phase targeted the second accelerating stage and involved the replacement of the 433 MHz klystron modulator. The new modulator, developed by Jema Energy, is based on a high-voltage Marx architecture designed to enhance pulse stability and overall system maintainability. The second phase focused on the first accelerating stage, which feeds the 144 MHz photo-injector. The original tetrode-based RF amplifier has been replaced by a high-power solid-state amplifier developed by AMPEGON, capable of delivering up to 1.6 MW peak power. A key challenge of this upgrade was achieving an architecture with a comparable footprint and thermal management constraints to the former tube-based system while preserving RF performance specifications. The upcoming third phase will undertake a complete redesign of the RF system powering the 1.3 GHz third accelerating stage, including the development of new accelerating cavities and their associated high-power RF source. This contribution provides an overview of the upgrade program, detailing the design considerations, testing, commissioning, and integration activities. It also discusses the technological choices implemented and the operational experience gained throughout the process.
Paper: THP2086
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-THP2086
About: Received: 11 May 2026 — Revised: 21 May 2026 — Issue date: 22 May 2026
THP2096
RF phasing for ELI-GBS linear accelerator
3626
The RF linac for the ELI - Gamma Beam Source (ELI-GBS) is being installed in Bucharest-Magurele (Romania). TW accelerating structures and SLED cavities are powered by klystrons via waveguide network that includes directional couplers for power monitoring and feedback. Before RF conditioning can begin, the linac must be properly tuned in terms of the RF phase and frequency. The waveguide system was reviewed with respect to its electrical length to ensure correct RF phase tuning. This work was carried out after installation but prior to connecting the waveguides to the accelerating structures. Fine RF-phase adjustments will be achieved through mechanical deformation of the waveguides. Since each klystron feeds four structures, the waveguides must be tuned so that the RF phase at the entrance of each structure matches its longitudinal position in the accelerator. Considering the fact that only 5-degree deviation in phase can be compensated by mechanical deformation of waveguides, larger discrepancies must be corrected physically by bending existing waveguide components to correct position or even reposition accelerator segments. Therefore precise analysis of the waveguide network was performed using a network vector analyzer. This paper reports the results of phase measurements performed on the assembled waveguide system. In addition, directional couplers were individually tested with VNA to verify their performance before integrating them into the system.
Paper: THP2096
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-THP2096
About: Received: 16 Apr 2026 — Revised: 16 May 2026 — Issue date: 22 May 2026
THP2100
Compression and linearisation studies on CLARA
3629
CLARA is a 250 MeV/celectron beam user facility currently undergoing final beam commissioning at Daresbury Laboratory, in the UK. CLARA features a 4-dipole variable bunch compressor, allowing a wide range of R56 values up to 60 mm, coupled with an X-band fourth harmonic cavity (4HC) for longitudinal harmonic correction of the S-band main linacs. An S-band transverse deflecting cavity (TDC) situated in a diagnostic straight following the bunch compressor, coupled with a high-resolution spectrometer beamline, enables full transverse and longitudinal reconstruction of the beam phase space. The FEBE arc, which delivers beam to a dedicated user area, can also act as an additional variable longitudinal compressor, with R56 variation of ±50 mm possible with limited dispersion leakage, and with 2 sextupole families for T566 correction. A Coherent Transition Radiation (CTR) target is situated at the exit of the arc and can be used for longitudinal tuning. Commissioning of the various longitudinal compression and linearisation systems has recently taken place, to facilitate a first tranche of “friendly” user experiments, several with demanding requirements on the bunch length.
Paper: THP2100
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-THP2100
About: Received: 11 May 2026 — Revised: 20 May 2026 — Issue date: 22 May 2026
THP2101
A semi-analytic, matrix-based model for the beam arrival time jitter
3633
The beam arrival time jitter is an important parameter for many advanced electron accelerators, including next-generation XFEL drivers. Accurate jitter modelling is particularly important during the design of a new facility, where it is often used to determine the tolerances of the RF sources and photoinjector laser. Conventionally, jitter is modeled using computationally intensive start-to-end simulations; in this approach, the entire accelerator is simulated many times, while the parameter associated with each jitter source is varied within its expected tolerance. This approach is time-consuming and scales poorly with the size and complexity of the accelerator. Semi-analytic jitter models therefore have significant advantages, owing to their speed and greater insight into the underlying physics. In this contribution, we propose a simple matrix-based model for the arrival time jitter in a linear accelerator with an arbitrary layout. We validate the model against simulations of CLARA at Daresbury Laboratory, and use it to explore the jitter tolerances of different operating modes.
Paper: THP2101
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-THP2101
About: Received: 12 May 2026 — Revised: 21 May 2026 — Issue date: 22 May 2026
THP2111
Reduced vertical beta function in KARA’s short straight sections for future R&D
3652
The KARA storage ring is operated as an accelerator test facility for research and development. It consists of four long and four short straight sections and presently operates five insertion devices (IDs). Four IDs are placed in the long straights with low vertical beta functions and one wiggler resides in a short straight section with a high vertical beta function. For future research and development experiments, a short straight with a lower vertical beta function is desired. Therefore, a new optics has been designed with a lower vertical beta function in the short straights. This new optics has been established in simulations and has recently been commissioned in the machine. Efforts are ongoing to push the vertical beta function even lower. This contribution will report on the ongoing efforts in establishing this new optics.
Paper: THP2111
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-THP2111
About: Received: 13 May 2026 — Revised: 20 May 2026 — Accepted: 20 May 2026 — Issue date: 22 May 2026
THP2124
ELI-NP Gamma-ray Beam System - status update and future
3676
The high brilliance ELI – Gamma-ray Beam System (ELI-GBS) is under implementation at Extreme Light Infrastructure - Nuclear Physics (ELI-NP) in Romania. The system uses an 800 MeV S-band accelerator driver as an Inverse Compton Scattering (ICS) source coupled to an interaction laser and in the future to a high-finesse optical cavity. The γ-ray beam will be available with energies up to 19.5 MeV to drive an ambitious scientific program which requires high spectral density (larger than 5×10^3 photons/s/eV), narrow bandwidth of 0.5%, and linear polarization higher than 95%. The ELI-GBS is foreseen to be finalized in an initial configuration in 2026. Details of the status of the LINAC, interaction laser system, and challenges for completing the system will be highlighted.
Paper: THP2124
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-THP2124
About: Received: 05 May 2026 — Revised: 21 May 2026 — Issue date: 22 May 2026
THP2130
From Cs3Sb to Cs2Te photocathodes on ELSA accelerator at CEA DAM
3694
The 19 MeV electron linear accelerator ELSA at CEA DAM operated as an IR‑FEL in the 1990s and is now a user facility that provides pulsed bremsstrahlung and Inverse Compton Scattering (ICS) X‑rays. Renovation of the facility is currently under way to improve system reliability. The 144 MHz photo‑injector gun is the key element for producing a low‑emittance beam for the ICS X‑ray source. While the refurbishment of the 144 MHz RF source has increased the photo‑injector’s reliability, the short lifetime of the photocathodes has become the facility’s weak point. A first step toward higher beam availability for users is to replace the Cs₃Sb photocathodes with Cs₂Te, which is known to have a longer lifetime. The drawback of this material is that it requires illumination with UV light, resulting in less laser energy available for photon‑to‑electron conversion compared with visible‑light operation. This paper will present the fabrication process, compare the two materials in terms of quantum efficiency and lifetime, and describe the laser‑system upgrades needed to maintain the same electron‑beam current.
Paper: THP2130
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-THP2130
About: Received: 11 May 2026 — Revised: 20 May 2026 — Issue date: 22 May 2026
THP2134
Photocathode development plan for DALI multifunctional facility
3708
DALI is an accelerator-based terahertz (THz) light source that uses multiple superconducting accelerators to drive CW electron bunches through undulators to emit ultra-intense THz pulses, including two ELBE SRF photo injects as the e- sources for high bunch charge beamline and for the UED, respectively. It requires a versatile portfolio of photocathodes to support diverse electron gun configurations and beam parameters targets. For the SRF gun commissioning, robust polycrystalline copper cathodes and magnesium cathodes will be employed, providing reliable performance and simplified handling during initial RF conditioning. Beam commissioning and routine user operation will firstly rely on the mature Cs₂Te photocathode, chosen for their proven robust, stability and realiable quantum efficiency. To enhance operational flexibility, especially in scenarios where UV laser generation presents challenges for special user appliations, we will consider to apply high-efficiency “green” photocathode optimized for visible-wavelength drive lasers. In parallel, an ultra-low-emittance photocathode in tens of micrometers will be under investigation to meet the stringent beam quality requirements of UED applications. This multi-cathode strategy ensures reliable commissioning, user-friendly operation, and state-of-the-art beam performance across all beamlines of the new accelerator facility.
Paper: THP2134
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-THP2134
About: Received: 13 May 2026 — Revised: 18 May 2026 — Accepted: 18 May 2026 — Issue date: 22 May 2026
THP2143
Delivery of caesium telluride photocathodes to the CLARA accelerator at Daresbury Laboratory
3729
High performance electron accelerators require high brightness electron beams. To achieve this a photocathode with a high quantum efficiency (QE) and low intrinsic emit- tance is required while also being robust with a long lifetime and low dark current. Photocathodes based on alkali metals can fulfil these requirements and, as such, are an important area of research for the accelerator physics community. The Compact Linear Accelerator for Research and Ap- plications (CLARA) at STFC Daresbury Laboratory has recently been upgraded from a copper photocathode to a cae- sium telluride photocathode. This has enabled a significant increase in bunch charge for a fraction of the laser power. We discuss the process of manufacturing and polishing molyb- denum photocathode plugs and the subsequent deposition of caesium telluride thin films. Three photocathodes have been provided to the CLARA facility with consistent and high quantum efficiency. One of these photocathodes has been successfully operating in CLARA since September 2025 with a stable QE of approximately 11 %.
Paper: THP2143
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-THP2143
About: Received: 11 May 2026 — Revised: 19 May 2026 — Issue date: 22 May 2026
THP2154
Design, training and magnetic field characterization of the superconducting THz-undulator coils for FLUTE
3761
FLUTE, a short-pulse linac and short-bunch THz test facility, serves as an accelerator test setup for a variety of accelerator physics studies. In its final stage of expansion, it is foreseen to provide coherent radiation in ultra-short, very intense light pulses in the terahertz and far-infrared spectral range. A superconducting undulator (SCU) at the end of the accelerator structure offers the possibility to generate photon radiation between 4 THz and 12 THz (energies between 16.5 meV and 50 meV) with a high pulse energy. This energy range, for instance, is of interest for studies of water-soluble interactions. The final undulator design was carried out by Bilfinger Nuclear & Energy Transition GmbH (BNET) in close collaboration with the Institute for Beam Physics and Technology (IBPT) of the Karlsruhe Institute of Technology (KIT). Before assembling the final undulator device the superconducting coils were trained and magnetically characterized in CASPER II, a magnetic measurement setup which is part of the Magnet and Cryogenics Facilities (MCF) at the IBPT at KIT. In this contribution we describe the general SCU layout, presenting the results of the coil training, the local magnetic field characterization and field integral minimization of the THz-undulator coils.
Paper: THP2154
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-THP2154
About: Received: 12 May 2026 — Revised: 18 May 2026 — Accepted: 20 May 2026 — Issue date: 22 May 2026
THP3001
A versatile beam splitting system for simultaneous delivery of three beams to industrial applications at the GANIL accelerator
3782
The demand for heavy-ion irradiation in space applications has grown significantly in recent years, surpassing the available beam time at GANIL. To address this, we are developing an innovative beam splitting system combining stripper/degrader techniques with two large-aperture DC magnetic septa. The originality of this approach lies in generating and transporting three different charge states obtained through partial stripping (typically from a 129Xe48+ beam at 50 MeV/u). These charge states are selected, separated from each other by the two septa and directed to three independent beamlines. These lines remain adjustable to accommodate various ion beams and magnetic rigidities. A key challenge is ensuring full operational independence of the beamlines, including control of beam intensity and access to experimental areas, which requires significant reconfiguration of the facility. Unlike time-sharing systems using fast switching magnets, our concept optimizes ion accelerator efficiency through a full parallel operation with a 100% duty cycle. This upgrade will enable simultaneous irradiations in three experimental areas, greatly enhancing GANIL's capacity to support high-demand, long-term irradiation programs. Moreover, this concept could be applied to other accelerator facilities desiring to feed multiple irradiations setup simultaneously without switching magnets.
Paper: THP3001
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-THP3001
About: Received: 12 May 2026 — Revised: 20 May 2026 — Accepted: 20 May 2026 — Issue date: 22 May 2026
THP3004
Hybrid optimisation of THz-driven tapered waveguides for synchronous acceleration of weakly relativistic high-quality electron bunches
3785
Downscaling particle accelerators is crucial to expanding their range of applications. Dielectric-lined waveguides (DLWs) can support hybrid modes with a strong accelerating component. Excited by terahertz (THz) frequency pulses, DLWs can deliver high accelerating gradients over cm-scale interaction lengths, promising the development of future compact electron accelerators. By precisely tailoring the waveguide geometry, the modal field profile and phase velocities can be tuned to maintain synchronisation between the weakly relativistic bunches and the accelerating mode over extended distances. Here, we design and evaluate THz-driven tapered DLWs delivering high-quality, MeV-level electron bunches in two types of symmetrical DLW waveguides: rectangular and cylindrical. We use analytic models of accelerating modes to simulate transport and acceleration of an externally injected 100-keV electron beam across various DLW geometries. A genetic algorithm is employed to identify Pareto-optimal geometries based on the final bunch characteristics.
Paper: THP3004
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-THP3004
About: Received: 13 May 2026 — Revised: 20 May 2026 — Issue date: 22 May 2026
THP3308
Design of a short-pulse septum power splitter for distributed X-band high-gradient acceleration
3797
Using short radiofrequency (RF) pulses is a promising method for increasing achievable accelerating gradients while significantly suppressing RF breakdown probability. However, short-pulse operation requires a structure with a commensurately low filling time to ensure efficient gradient buildup. To achieve this, we utilize a distributed power coupling scheme that delivers RF power to each cavity simultaneously through a waveguide array. This parallel feeding mechanism drastically reduces the filling time of the entire accelerating structure compared to traditional series-fed designs. Furthermore, this topology allows for greater flexibility in cavity optimization and yields higher shunt impedance.This work presents the design and simulation of a novel septum power splitter specifically engineered to drive an accelerating structure in this short-pulse regime. The splitter is integrated with a four-cell prototype, enabling each cavity to be powered individually and concurrently. The system is designed for short 𝑋-band RF pulses with peak powers up to 400 MW at 11.7 GHz. The four-cell structure is over-coupled and maintains a (2/3)𝜋 phase advance between adjacent cells. CST simulation results confirm the performance of this design in achieving high accelerating gradients. Finally, we outline the experimental plan for the prototype demonstration at the Argonne Wakefield Accelerator.
Paper: THP3308
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-THP3308
About: Received: 13 May 2026 — Revised: 20 May 2026 — Issue date: 22 May 2026
THP3309
Modernizing the AWA facility: enhanced beam quality and capabilities for high-gradient RF and beam physics research
3801
The Argonne Wakefield Accelerator (AWA) is a 1300 MHz, 65 MeV normal-conducting photoinjector LINAC supporting a broad research program in high-gradient RF acceleration, beam physics, and AI/ML-based accelerator operations. The facility produces electron bunches span-ning 1 pC to 100 nC, including high-charge (~100 nC, ~25 kA), high-brightness (~hundreds nm emittance), and arbitrarily shaped formats, and delivers beam to 5 device-under-test zones along two primary experimental beam-lines. Over the past decade the AWA has undergone exten-sive modernization, including replacement of the drive gun with an RF-symmetrized photoinjector; upgrade of the drive laser from a 248 nm excimer to a 262 nm Ti:sapphire system; transition to a distributed EPICS-based control system; and deployment of a digital LLRF system developed by the LBNL BACI group. Recent experiments have demonstrated accelerating gradients >300 MV/m in X-band structures, peak cathode fields >400 MV/m, and beam-driven RF power generation >565 MW. Near-term plans include RF-symmetrized linac cavity replacements and an asymmetric EEX beamline upgrade. A proposed AWA-II upgrade would double the beam energy to ~130 MeV, further expanding the facility’s reach for high-gradient RF and beam physics research.
Paper: THP3309
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-THP3309
About: Received: 13 May 2026 — Revised: 21 May 2026 — Issue date: 22 May 2026
THP3311
Hofmann stability charts revisited for PIP-II: from classical theory to assumption-free and ML-Driven maps
3805
The Hofmann stability chart remains a standard for visualizing parametric resonances in space-charge–dominated linacs, but its use typically relies on non-oscillatory Vlasov dispersion relations with simplifying assumptions (continuous focusing, KV phase space, linear optics, limited transverse–longitudinal coupling). We revisit the chart for the PIP-II linac along three tracks. (1) We reproduce the conventional maps in the (νz/νx, νx/ν0x) plane for relevant εz/εx, providing a validated reference. (2) We remove key assumptions by deriving stability surfaces directly from multi-particle tracking with realistic lattice discreteness, RF defocusing, solenoid/quad optics, and bunched-beam dynamics; local tunes and early-time growth rates are estimated from envelope oscillations and projected to the same coordinates. These assumption-reduced maps recover the canonical stopbands while revealing shifts and broadenings driven by tune modulation, non-KV distributions, and transverse–longitudinal coupling at PIP-II intensities. (3) We train a compact machine-learning surrogate that emulates the growth surface from zero-current optics, tune depression, emittance ratio, bunching factor, and selected lattice descriptors, enabling rapid scans and online working-point selection. We compare the three representations on representative PIP-II sections and discuss implications for commissioning guard bands, resonance avoidance, and routine operations.
Paper: THP3311
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-THP3311
About: Received: 18 May 2026 — Revised: 20 May 2026 — Issue date: 22 May 2026
THP3314
Design and optimization of a 10.0625 MHz low-frequency buncher for a 201.25 MHz RFQ accelerator
3808
The LANSCE Accelerator Modernization Project (LAMP) will replace the front-end of the existing LANSCE accelerator, from ion sources through the end of the 100-MeV drift-tube linac. The LAMP design includes injecting a bunched beam into an RFQ. The RFQ test stand (RFQTS) will demonstrate this technique using an existing RFQ. This paper discusses the design of the low frequency buncher for the RFQTS. CST simulations were used to study the effects of gap length, bunching voltage, and beam-pipe aperture on the transmission efficiency, transit-time factor, emittance growth, and bunching efficiency. The optimized LFB provides effective pre-bunching, while a downstream solenoid focuses the beam to minimize transverse emittance growth and ensure proper injection into the RFQ.
Paper: THP3314
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-THP3314
About: Received: 14 May 2026 — Revised: 20 May 2026 — Issue date: 22 May 2026
THP3325
High-gradient radiofrequency photoinjector with a detachable cathode Assembly
3812
We present an RF photoinjector architecture that utilizes the TM$_{02}$ mode in the first half-cell housing the cathode. Unlike the conventional TM$_{01}$ mode configuration, this design introduces a controlled discontinuity in the surface field, producing a region free of surface currents. This unique topology allows the cathode to be mechanically separated from the gun body without compromising RF performance or requiring precise electrical continuity at the interface. The photoinjector should, in principle, deliver a very high cathode gradient and, consequently, high beam brightness. At the same time, the detachable cathode assembly is compatible with load-lock systems, which can transfer high QE semiconductor cathodes into high-gradient RF photoinjector structures under UHV.
Paper: THP3325
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-THP3325
About: Received: 13 May 2026 — Revised: 21 May 2026 — Issue date: 22 May 2026
THP3603
Design of an S-band choke-mode travelling-wave accelerating structure
3815
Charged particle bunches excite wakefields in acceler-ating cavities, and the transverse components of these wakefields can degrade beam stability. Since these effects are mainly driven by higher-order modes (HOMs), effec-tive HOM suppression is essential for accelerator opera-tion. The choke-mode structure is one of the approaches used for HOM damping. This study presents the design of a 2856 MHz S-band choke-mode travelling-wave accelerating structure. The fundamental-mode parameters of the single cell and cavi-ty chain are optimized using electromagnetic simula-tions. HOM characteristics and wakefields are analyzed using HFSS and CST simulations, and a two-step optimi-zation of the choke geometry is performed. The results show a clear reduction in transverse wake impedance, demonstrating effective HOM suppression.
Paper: THP3603
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-THP3603
About: Received: 13 May 2026 — Revised: 20 May 2026 — Accepted: 20 May 2026 — Issue date: 22 May 2026
THP3604
Dual-pillar dielectric laser acceleration structure for relativistic electrons
3818
Dielectric-laser accelerator (DLA) can provide accelerating gradients on the order of GV/m and is therefore considered a promising alternative to conventional radio-frequency accelerators. Extending DLA to relativistic electrons is still at an early stage and this research is important for achieving fully miniaturized accelerators. In this paper, we optimize dual-pillars DLA structures and evaluate their performance through numerical simulations. The results indicate energy gain for individual relativistic electrons as well as for a relativistic electron bunch. The simulation results will be used as guidance for the fabrication of the structures and the upcoming acceleration experiments.
Paper: THP3604
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-THP3604
About: Received: 13 May 2026 — Revised: 20 May 2026 — Accepted: 20 May 2026 — Issue date: 22 May 2026
THP3605
Design of a dielectric laser accelerator structure for low β charged particles
3822
Dielectric laser accelerator (DLA) is a novel acceleration scheme using dielectric nanostructures with high damage thresholds for the laser electric field. In DLA, the typical structural period is determined by the product of the Lorentz factor β and the laser wavelength λ. At low β, the structural period becomes extremely small, making fabrication impractical and limiting the range of initial energies that can be accelerated. In fact, DLA has so far been demonstrated only for initial energies above approximately 10 keV [1–3]. We design DLA structures that extend the range of initial kinetic energy that can be accelerated to lower energies. By setting the structural period to an odd multiple of βλ and specifically employing a 3βλ structure in this work, the fabrication constraints associated with low initial energies can be improved. As a result, acceleration is driven by enhanced third-order Fourier components of the laser field generated during transmission through the pillars, rather than by the original incident laser component. In this presentation, we will report on a pillar cross-sectional design capable of accelerating low-energy electrons (5 keV) based on acceleration simulations.
Paper: THP3605
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-THP3605
About: Received: 13 May 2026 — Revised: 19 May 2026 — Issue date: 22 May 2026
THP3613
Preliminary Design of an RF-focused Interdigital Drift Tube Linac
3825
A standard Interdigital Drift Tube Linac accelerates particles in a pi-mode cavity using drift tubes suspended alternately from opposite walls. It typically requires external magnetic quadrupoles in a Focusing-Drift-Defocusing-Drift lattice for transverse focusing. The RF-focused DTL innovates by shaping the drift tubes themselves as RF quadrupoles (like a short section of an RFQ). This integrates transverse focusing directly into the accelerating structure, eliminating the need for separate magnetic quadrupoles. This leads to a more compact, mechanically simpler, and potentially cheaper system, ideal for applications like medical isotope accelerators, injectors, or compact neutron sources.
Paper: THP3613
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-THP3613
About: Received: 08 May 2026 — Revised: 18 May 2026 — Issue date: 22 May 2026
THP4002
New capabilities of SIS18 after upgrade program as FAIR injector
3853
SIS18, the main synchrotron of the present GSI accelerator complex, will serve as booster for the FAIR facility. Several major and minor upgrade programs were realized since 2008 to improve SIS18 for this purpose. We will report on new capabilities of the synchrotron for present and future user operation, which were not directly attributed to FAIR injector operation. Namely, a spill feedback system to control macroscopic spill shape and optimize spill microstructure during slow extraction. The operation of SIS18 with the new FAIR control system in conjunction with the RF upgrades allows beam operation without restrictions at lower injection energies. Acceleration of two beams consisting of ions with different mass to charge ratios at different revolution frequencies during acceleration are now possible and were successfully demonstrated in 2025. Possible users are medical research and plasma physics. As outlook we describe future plans for beam shaping before fast extraction for medical research.
Paper: THP4002
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-THP4002
About: Received: 13 May 2026 — Revised: 21 May 2026 — Issue date: 22 May 2026
THP4006
Non-linear resonance feed-down - a new technique for correcting high order errors in the LHC
3861
Optics errors from the interaction points of the LHC, where β* is most strongly squeezed, can significantly impact machine performance and protection. In anticipation of the HL-LHC, correction strategies extending up to dodecapole order are being targeted. Direct measurement of high-order resonance driving terms (RDTs) remains challenging, however. Applying crossing angle orbit bumps in the experimental insertions induces feed-down from higher-order errors, increasing the magnitude of lower-order RDTs. Leveraging this effect, a novel correction scheme based on RDT feed-down was implemented for the first time in 2025. Skew-octupole errors were successfully corrected, which enabled optics measurements at the collisions working point, down to an unprecedented level of β*=18cm. Measurements of feed-down from dodecapole errors, to decapole RDTs were also achieved, opening a practical pathway to efficient corrections of very high-order optics errors.
Paper: THP4006
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-THP4006
About: Received: 13 May 2026 — Revised: 19 May 2026 — Issue date: 22 May 2026
THP4014
Implementation update of MYRRHA phase 1 (Minerva)
3885
This contribution provides an update on the development of the 4 mA, 100 MeV continuous-wave (CW) superconducting proton linac - the first stage of MYRRHA’s accelerator-driven system (ADS). We present the improved accelerator layout and beam optics design, outline the key design choices for critical components, and report on the latest manufacturing and civil construction progress.
Paper: THP4014
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-THP4014
About: Received: 29 Apr 2026 — Revised: 19 May 2026 — Accepted: 19 May 2026 — Issue date: 22 May 2026
THP4015
Construction status of the NEWGAIN RFQ
3889
A new injector called NEWGAIN will be added to the SPIRAL2 Linear Accelerator in parallel with the existing one. It will be mainly composed of an ion source and a Radio Frequency Quadrupole (RFQ) connected to the superconductive LINAC. The RFQ is a standard four-vane bulk copper cavity, composed of 7 segments of about 1m. The new RFQ will accelerate at 88.05MHz particles with charge-over-mass ratio (Q/A) between 1/3 and 1/7, from 10 keV/u up to 590 keV/u. This paper will present the status of the RFQ section fabrication and its necessary support systems. The fabrication and delivery of these components will lead to its installation, which is a major milestone for the project.
Paper: THP4015
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-THP4015
About: Received: 05 May 2026 — Revised: 18 May 2026 — Accepted: 18 May 2026 — Issue date: 22 May 2026
THP4016
Status of the IH-DTL cavities design and prototyping for the ICONE project
3892
CEA is committed to delivering a LINAC in the frame of the ICONE project, in order to accelerate an 80-mA beam of protons up to 25 MeV, with a duty cycle of 6%. The LINAC project is divided into five workpackages: Source and LEBT, RFQ, MEBT, DTL and HEBT. The initial acceleration and bunching will be provided by a 4-vane RFQ cavity. For the DTL part, two solutions with copper cavities were studied from 3.7 MeV to the final energy: an IH-DTL and an Alvarez DTL LINAC. This talk will present the design of the IH-DTL solution at 352 MHz. Prototypes of certain parts, including a small cavity, and a permanent magnet, are tested in 2025/2026. Results of these tests will be presented.
Paper: THP4016
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-THP4016
About: Received: 13 May 2026 — Revised: 20 May 2026 — Accepted: 20 May 2026 — Issue date: 22 May 2026
THP4019
Towards automated cavity failure compensation in the SPIRAL2 SC linac
3899
SPIRAL2 is a superconducting linac located in Caen, France. It is designed to accelerate intense ion beams with A/Q ratios ranging from 1 to 7, which can be used in various experimental facilities for nuclear physics and applied research. In this machine, RF systems have been identified as a major source of beam interruptions*, limiting the overall availability of SPIRAL2. Cavity failure compensation is a beam dynamics approach that can mitigate the duration of such beam trips by allowing operation without the failed systems. In 2025, following an actual cavity failure, this method enabled SPIRAL2 to operate for two months with the failed cavity removed from operation, while recovering a nominal beam**. However, determining suitable compensation settings remains a time-consuming and error-prone task. To address this challenge, we are developing LightWin***, an automatic tool dedicated to cavity failure compensation. In this study, we present our latest developments and introduce acceptance-preserving compensation strategies that have proven effective for the SPIRAL2 superconducting linac.
Paper: THP4019
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-THP4019
About: Received: 13 May 2026 — Revised: 21 May 2026 — Issue date: 22 May 2026
THP4020
Status of the new heavy ion Alvarez-Type Injector at GSI
3903
The Alvarez-type drift-tube LINAC (DTL) at GSI presented here accelerates intense heavy-ion beams with A/q ≤ 8.5 from 1.4 to 11.4 MeV/u. It replaces a DTL being more than 45 years old, in order to satisfy the requirements of future FAIR operation. The 108.408 MHz Alvarez DTL design has been finalized since 2021, and all tank sections for the 55 m long post-stripper injector have been manufactured. Advanced copper-plating procedures had to be developed for the 2 m long and 2 m diameter tank sections as well as for the drift tubes. These two different plating processes are now successfully applied in series production, ensuring uniform layer quality and low RF-critical surface roughness. The first five of 25 tank sections and over 20 drift tubes have been plated to specification, confirming production stability. The first batch of drift tubes with internal pulsed quadrupoles has undergone magnetic acceptance measurements, to confirm compliance with the field-quality and gradient requirements. This contribution reports the current project status, highlights the assembly of the drift tubes and the electrical connection of the internal quadrupoles.
Paper: THP4020
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-THP4020
About: Received: 12 May 2026 — Revised: 19 May 2026 — Accepted: 19 May 2026 — Issue date: 22 May 2026
THP4021
Heavy ion focusing using a Gabor Lens inside a drift tube structure
3907
Space-charge lenses based on confined non-neutral plasmas, such as electron clouds, provide strong, axially symmetric focusing for high-intensity ion beams and serve as an alternative to conventional quadrupole magnets. The so-called Mobley drift tube integrates a Gabor-Lens (GL) into a drift tube of a linear accelerator, enabling beam focusing within an accelerating RF structure. The confined electron cloud does not come into direct contact with the accelerating field; a re-entrant snout geometry is introduced and optimized to minimize the RF field amplitude in the region where the electron cloud forms. Confinement of sufficiently high electron density is achieved in the beam pipe of the drift tube without any external electron source, relying solely on self-sustained processes. This contribution presents simulations and RF measurements of an RF- and vacuum-compatible prototype Mobley drift tube designed for heavy-ion beams, providing insight into the operational feasibility and focusing performance of Gabor-lenses integrated in LINAC drift tubes.
Paper: THP4021
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-THP4021
About: Received: 12 May 2026 — Revised: 19 May 2026 — Issue date: 22 May 2026
THP4022
Accelerator development for the High Brilliance Neutron Source (HBS-I)
3911
Neutrons are an indispensable tool for science and industry to study the structure and dynamics of matter from the meso to the pico scale and from seconds to femtoseconds. An attractive way to provide urgently needed neutrons in the near future is to build efficient high-current, accelerator-based neutron sources (HiCANS) using pulsed proton beams. A new national research infrastructure that benefits significantly from these developments will be the High Brilliance Neutron Source (HBS-I), which was recently shortlisted by the Federal Ministry of Research, Technology, and Space (BMFRT). HBS-I uses pulsed 100 mA high-current proton beams to generate neutrons through a low-energy nuclear reaction at 20 MeV in a target material, which requires less radiation shielding and moderator cooling compared to conventional neutron sources. The facility is designed to produce small-diameter neutron beams, enabling experiments with smaller sample volumes. This will support research in materials and life sciences, including materials for energy conversion and storage, nanomaterials, quantum materials, protein structures, and biomaterials. The facility is intended for use by a multidisciplinary community of universities, research institutions, and industry. The basic concept and its realization will be presented.
Paper: THP4022
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-THP4022
About: Received: 11 May 2026 — Revised: 21 May 2026 — Accepted: 21 May 2026 — Issue date: 22 May 2026
THP4023
First Beam Test of an Additively Manufactured H-Mode Linac Structure made from Pure Copper
3915
We present results from a 1.4 MeV proton beam test of the first IH-Type linac structure additively manufactured (AM) from pure copper. The cavity has been tested up to 25 kW at a duty cycle of 2 %, which corresponds to a cavity voltage of 1 MV with peak fields at the drift tubes reaching up to 68 MV/m without RF breakdown at full power. A 1.4 MeV proton beam from a Van de Graaff accelerator has been accelerated up to 2.2 MeV, demonstrating the effective acceleration voltage of 0.83 MV at full power. These high power beam tests show performance en par with conventionally manufactured H-mode structures, paving the way for future linac structures benefiting from the advantages of additive manufacturing.
Paper: THP4023
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-THP4023
About: Received: 03 May 2026 — Revised: 15 May 2026 — Accepted: 16 May 2026 — Issue date: 22 May 2026
THP4026
Update on ESS Medium Beta cavities at INFN LASA
3919
INFN LASA is involved in delivery four MBcavities to ESS Eric as part of the Italian In-Kind Contribution to the “operation Phase”. The cavities have been fabricated and tested naked before the integration into the He-tank. After successful performance verification, the cavities have been integrated and finally validated at DESY AMTF before their delivery to CEA for installation into the cryomodule. We report the results of the fabrication and tests as well as lessons learned.
Paper: THP4026
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-THP4026
About: Received: 13 May 2026 — Revised: 19 May 2026 — Issue date: 22 May 2026
THP4027
INFN LASA activities toward PIP-II
3922
INFN LASA is advancing its in-kind contribution to the PIP-II project at Fermilab, with significant progress achieved in both cavity production and testing infrastructures. The main activity is the fabrication of 38 five-cell β = 0.61 superconducting cavities for the LB650 section of the linac. Manufacturing is well advanced with mechanical production of the series cavities progressing while the two pre-series ones are being used to validate the complete industrial workflow, including surface processing and final preparation, that is mostly entrusted to industrial partners. Crucial to ensure compliance with the stringent performance requirements of PIP-II, all cavities will undergo final qualification through a vertical cold tests facility at DESY AMTF (Germany) that is being finalized and commissioned. Lastly cavities will proceed with the delivery to CEA Saclay (France) as fully validated components ready for string assembly. This contribution summarizes the status of these activities, presenting updates from the manufacturing of series cavities, results from pre-series qualification and recent upgrades to both LASA and DESY the testing infrastructures.
Paper: THP4027
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-THP4027
About: Received: 13 May 2026 — Revised: 19 May 2026 — Accepted: 21 May 2026 — Issue date: 22 May 2026
THP4030
ARGITU RFQ bead-pull tuning and RF tests at ESS-Bilbao
3926
In this paper we describe the static tuning procedure of the ARGITU/HiCANS-platform RFQ at ESS-Bilbao. The machining and assembly of the RFQ were finished during 2025. The cavity is a 3.1 meters long, 4-vane cavity operating at 352.2 MHz. It will accelerate a 40 mA (designed up to 65 mA) proton beam from 45 keV to 3.0 MeV. The RFQ will operate at 1% duty cycle in the first stages of the ARGITU HICANS platform, and later as the injector of the linac at a maximum duty cycle of 5%. The static tuning of the cavity has been carried out combining the field profiles measured by a bead-pull technique with the aid of both a conventional "SVD" algorithm and a novel genetic algorithm that was required due to the available tuners range at the operational frequency. The whole procedure and the results are described in this paper, as well as other tests at low power RF and with the cooling water in operation. The stability of the field profiles and the cavity frequency with respect to the cooling water temperature are also investigated.
Paper: THP4030
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-THP4030
About: Received: 12 May 2026 — Revised: 20 May 2026 — Accepted: 20 May 2026 — Issue date: 22 May 2026
THP4032
RF Design and Beam Dynamics of a $({S_c^{\mathrm{max}}/E_a^2})/{ZTT}$-Optimized 3 GHz SCDTL for Carbon Ion Acceleration in a Medical Injector
3932
This study presents a comprehensive methodology for the RF design and optimization of a 3 GHz SCDTL structure in terms of the modified Poynting vector $S_c$ and the effective shunt impedance $ZTT$. By systematically refining the geometry of both accelerating and side-coupling cavities, the design achieves a maximized effective shunt impedance and accelerating gradient, while ensuring compliance with breakdown limits based on the modified Poynting vector. The optimized structures are subsequently used to investigate beam dynamics constraints for a representative C$^{6+}$ carbon ion beam, which is pre-accelerated in 750 MHz structures up to 10 MeV/u and then further accelerated in the proposed SCDTL structures from 10 MeV/u to 85 MeV/u.
Paper: THP4032
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-THP4032
About: Received: 12 May 2026 — Revised: 21 May 2026 — Issue date: 22 May 2026
THP4033
Outcomes of the DONES consolidation project activities
3936
IFMIF-DONES is an ESFRI facility based on a 40 MeV, 5 MW beam power deuteron accelerator and a liquid lithium target currently under construction in Granada (Spain) as part of the European roadmap to fusion electricity. Its main goal is to characterize and qualify materials under a neutron field with an induced damage similar to the one expected in a fusion reactor, developing a material database for the future fusion nuclear power plants. Moreover, a number of medium neutron flux experiments in other irradiation areas for fusion and non-fusion applications have been proposed and are under analysis. Although the construction phase is ramping up, the European EURATOM Project DONES-ConP1 has been directed at the preparation of the key documentation and to consolidate contributions from the parties. In this contribution, the main outcomes of the project, such as the first proposal of the DONES Experimental Programme, consolidation of the DONES users community, users and machine interfaces, the evolution of the ideas for the complementary experiments, organization and project documentation for safety licensing will be presented and described.
Paper: THP4033
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-THP4033
About: Received: 13 May 2026 — Revised: 20 May 2026 — Issue date: 22 May 2026
THP4037
FFA magnet prototype for high power pulsed proton driver
3944
The Fixed Field Alternating Gradient (FFA) accelerator is a natural candidate for a high-power pulsed proton driver, although no high-power FFA has yet been constructed. As a critical component of the accelerator, the main magnets have been the subject of particular study. Operational flexibility, in terms of machine optics, over a large range is an essential feature of such a machine. In order to explore this in more detail a dedicated FFA prototype magnet has been designed and manufactured. This magnet was manufactured and delivered to the Rutherford Appleton Laboratory (RAL) in the UK in April 2025, and field measurements are subsequently planned to establish its characteristics. This paper will discuss the design, manufacture, and measurement plans of the prototype magnet.
Paper: THP4037
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-THP4037
About: Received: 13 May 2026 — Revised: 19 May 2026 — Accepted: 21 May 2026 — Issue date: 22 May 2026
THP4038
Modelling of counter-rotating multi-turn wakefields in the muon collider RCS chain
3948
The future multi-TeV muon collider facility will employ a superconducting radiofrequency (RF) system with thousands of cavities in the rapid-cycling synchrotron (RCS) chain. This RF system, common to both beams, will accelerate two counter-rotating $\mu^+$ and $\mu^-$ bunches simultaneously. Due to the high intensity of up to $2.7 \times 10^{12}$ particles per bunch, the induced voltage in both the fundamental and several higher-order modes is significant. A strong impact on longitudinal beam quality and the luminosity in the collider is expected. Modelling wake potentials in the RF system of the RCS chain is challenging. The long-range wakefields will interact with both the co- and counter-rotating bunches due to the high quality factor and corresponding long decay constants of the fields in the cavities. These two-beam interactions are studied, with particular attention to the specificities caused by the directionality of the induced fields.
Paper: THP4038
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-THP4038
About: Received: 12 May 2026 — Revised: 20 May 2026 — Accepted: 20 May 2026 — Issue date: 22 May 2026
THP4046
Development of an Optical Beam Profile Monitor for the HZB Cyclotron
3972
The HZB cyclotron accelerator complex provides 68 MeV protons for proton therapy and related research. The main accelerator is an isochronous sector cyclotron served by two injectors. Originally, the cyclotron was designed for heavy ions. Hence, the beam profile monitors (BPM) on the high energy side are not appropriate for protons at the low intensities used for proton therapy. At the experimental station as well as the treatment station, the profile and shape of the beam is determined via a mirrored image of a scintillator screen in air. For the experimental station, a LabVIEW code has been developed which displays the shape, transverse beam distribution, size and position of the beam. As this tool proved to be very helpful when tuning the beam for experiments, an installation within the beam line in vacuum was designed for several locations where the beam is focused. The design of the new beam profile monitors and their performance will be presented.
Paper: THP4046
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-THP4046
About: Received: 23 Apr 2026 — Revised: 17 May 2026 — Accepted: 17 May 2026 — Issue date: 22 May 2026
THP4049
Traces of the Vortex Effect in PSI Injector II
3984
Injector II is part of PSI's high intensity proton accelerator (HIPA) facility. It is to date the only cyclotron worldwide that makes use of the a space-charge driven effect ("Vortex Effect") which causes bunches not to expand but to "roll up" in the horizontal plane. The effect prevents the cyclotron bunches from expanding longitudinally so that the phase width stays unusually small and the former flat-top resonators could be replaced by normal accelerating resonators. The effect has been simulated in PIC-codes like OPAL and experimentally verified by bunch shape measurements. We present measurements of radial probes which contain residual traces of this effect and we show how it is used to analyze and fit the beam optics in the transfer line between Injector II and the Ring Cyclotron.
Paper: THP4049
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-THP4049
About: Received: 12 May 2026 — Revised: 19 May 2026 — Issue date: 22 May 2026
THP4056
Machine physics studies for the MYRRHA Phase 1 linac at SCK CEN
3996
At the Nuclear Research Center SCK CEN in Belgium, the first phase of the MYRRHA project (an accelerator driven system) is under construction. Included in MYRRHA Phase 1 are a normal conducting injector linac (RFQ + CH cavities) and a super conducting linac (60 single spoke cavities), providing a CW proton beam of 4 mA and 100 MeV. In this contribution the recent changes to the MYRRHA Phase 1 linac design and the associated machine physics studies are reported. First of all, the layout of the MYRRHA linac was changed from two identical injector linacs each including a dog leg to one straight injector (for the MYRRHA phase 1) and a (future) second injector with a dogleg. The beam dynamics studies of the straight linac and two options for the second injector are presented. Secondly, the impact of a detailed mechanical integration of the beam line elements, which is a compromise between the ideal theoretical layout and a realistic and pragmatic implementation, on the longitudinal and transverse phase space distributions is discussed. Finally, the losses along the linac and their relation to the RFQ output distribution are presented.
Paper: THP4056
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-THP4056
About: Received: 06 May 2026 — Revised: 17 May 2026 — Accepted: 17 May 2026 — Issue date: 22 May 2026
THP4057
The Low Energy Beam Transfer (LEBT) line and RFQ for the MYRRHA Phase 1 facility
3999
At the Nuclear Research Center SCK CEN in Belgium, the first phase of the MYRRHA project (an accelerator driven system) is under construction. Included in MYRRHA Phase 1 are a normal conducting injector linac (RFQ + CH cavities) and a super conducting linac (60 single spoke cavities), providing a CW proton beam of 4 mA and 100 MeV. In this contribution we present simulations of the Low Energy Beam Transfer Line (LEBT) and the 4-rod RFQ. The LEBT, including an ECR ion source, 2 solenoids and a pair of slits, matches the continuous proton beam to the entrance of the RFQ. The RFQ accelerates and bunches the beam from 30 keV up to 1.5 MeV. The effects introduced by space charge and their effect on the output distribution out of the RFQ will be highlighted. A comparative study of the RFQ beam dynamics simulation perforemd with the codes TOUTATIS and DYNAC will be presented.
Paper: THP4057
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-THP4057
About: Received: 07 May 2026 — Revised: 18 May 2026 — Accepted: 19 May 2026 — Issue date: 22 May 2026
THP4078
Development and technical feasibility of the figure-8 storage ring concept for high current beam storage
4040
The Figure-8 Storage Ring (F8SR) is an innovative concept designed for storing low energy (<1MeV) proton and ion beams in stellarator-like geometry within strong magnetic field level (B~6-7T). Preliminary studies, presented at previous IPAC conferences, established key design principles and demonstrated the feasibility of a compact ring structure capable of high current beam confinement over extended periods. The unique figure-eight geometry supports long-term beam confinement, essential for fusion experiments within beam-plasma system and colliding beams optics. The experimental program included investigations of the magnetic lattice, orbit stability, beam diagnostics and vacuum performance, supported by simulations and prototype measurements. Results confirmed the reliability of the beam optical design and guided optimization of magnetic field configuration. A Technical Design Concept is now being prepared to define the full-scale implementation of the F8SR, consolidating engineering requirements and scientific objectives toward establishing an international platform for high-current beam studies.
Paper: THP4078
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-THP4078
About: Received: 13 May 2026 — Revised: 21 May 2026 — Issue date: 22 May 2026
THP4093
Flat C/He spills for online range monitoring in particle therapy
4079
The use of mixed ion beams is a developing approach aimed at improving current carbon-ion therapy by enabling online monitoring of dose deposition. In such a configuration, the main dose is still delivered by carbon ions, while lighter ions traverse the patient with negligible dose contribution and can be used for imaging. The main challenges of this approach include the need to simultaneously accelerate both ion species and to slowly extract them with a stable species ratio, a prerequisite for potential clinical application. At GSI, a mixed beam of 12C3+ and 4He+ ions was provided in May 2025 for biophysics experiments. The very small mass-to-charge difference of 0.065 % between these ion species enables simultaneous acceleration in the SIS18 heavy-ion synchrotron. To slowly extract them with transverse RF-knockout, chromaticity in the ring was adjusted, and the spill optimization system was used. These measures enabled a nearly rectangular spill with a constant helium/carbon ratio within the spill, confirmed by ionization-chamber measurements in the medical cave. This contribution presents the experimental results and discusses their implications for mixed-beam operation.
Paper: THP4093
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-THP4093
About: Received: 12 May 2026 — Revised: 20 May 2026 — Issue date: 22 May 2026
THP4094
Modifications of the high-energy beam transport at GSI and its subsystems for FAIR
4083
The High-Energy Beam Transport at GSI (GSI-HEBT) is a system of transfer lines which delivers heavy ion beams from the SIS18 synchrotron to various experiments, the fragment separator and the storage rings ESR and CRYRING@ESR. The High-Energy Beam Transport for FAIR (FAIR-HEBT) will also branch off from the GSI-HEBT. This connection is currently under construction and requires several modifications in the GSI-HEBT to accommodate FAIR beamline devices within tight space constraints. Furthermore, FAIR will be operated from a new, fully digital control room. Therefore, all remaining analog devices of GSI-HEBT had to be digitized, in particular the cameras of the scintillating screens and the fast current transformers. The power converters for the magnets in GSI-HEBT, which are needed for beam transport to FAIR, are currently being upgraded to FAIR standard. These modification of GSI-HEBT will be discussed in this paper in detail.
Paper: THP4094
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-THP4094
About: Received: 16 Apr 2026 — Revised: 16 May 2026 — Accepted: 16 May 2026 — Issue date: 22 May 2026
THP4096
Optimization of one and two-plane multi-turn injection in the SIS18 synchrotron
4091
In the SIS18 heavy-ion synchrotron at GSI, loss-induced vacuum degradation and reduced beam lifetime limit high-intensity operation with uranium ions. During multi-turn injection (MTI), even small localized losses can trigger pressure bump instabilities, making optimized injection control essential to reach FAIR intensity goals. We present a comprehensive study on optimizing the MTI process in the SIS18 synchrotron at GSI, combining experimental measurements and simulations. Online optimization using the derivative-free BOBYQA algorithm enabled direct improvement of machine performance. Multi-objective Bayesian optimization (BO) was applied to reconstruct the Pareto front experimentally between injection efficiency and beam losses, providing insight into the best achievable performance. On this basis, we introduce a multi-fidelity BO framework that integrates prior knowledge from low-fidelity models with high-fidelity experimental measurements, achieving improved sample efficiency. Complementary simulation studies on two-plane injection indicate a further potential for loss reduction. The results demonstrate effective, adaptive MTI optimization and support future autonomous tuning strategies.
Paper: THP4096
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-THP4096
About: Received: 17 Apr 2026 — Revised: 28 Apr 2026 — Accepted: 14 May 2026 — Issue date: 22 May 2026
THP4097
Robust real-time optimization of SIS18 injection using Gaussian Process MPC
4095
We present advancements in the data-driven Model Predictive Control (MPC) framework for optimizing multi-turn injection (MTI) into the SIS18 synchrotron. Building on our prior work on safe, sample-efficient optimization, we systematically investigate the impact of current noise and transverse emittance fluctuations. By incorporating realistic error models derived from dedicated measurements of fluctuations on injected current and emittance into simulations, we demonstrate that the Gaussian Process model effectively filters random uncertainty, maintaining robust operation where standard numerical optimizers degrade. Furthermore, we report on the successful deployment of the framework during live SIS18 tuning. The controller autonomously adjusted injection parameters, demonstrating reliable convergence, enhanced efficiency, and a substantial reduction in tuning iterations compared to model-free RL methods, which often face challenges in real-world applications. These results establish data-driven MPC as a powerful tool for real-time optimization in noisy, high-stakes accelerator environments, setting the stage for safe learning-based control across FAIR facilities.
Paper: THP4097
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-THP4097
About: Received: 15 Apr 2026 — Revised: 20 May 2026 — Issue date: 22 May 2026
THP4100
Commissioning of Helium Beams at CNAO
4103
CNAO (Centro Nazionale di Adroterapia Oncologica) is one of the few hadrontherapy centres all around the world that produce both proton and carbon ions beams. It is based on a synchrotron in which the beams are ex-tracted by a slow extraction mechanism by means of either a betatron core or an RFKO electrostatic exciter. Recently a third source, AISHa-CNAO (Advanced Ion Source for Hadrontherapy), has been installed to produce new species to be used for clinical or experimental pur-poses. In this article, we show the commissioning status of the helium beams generated by the new source.
Paper: THP4100
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-THP4100
About: Received: 05 May 2026 — Revised: 18 May 2026 — Accepted: 18 May 2026 — Issue date: 22 May 2026
THP4115
Alternative fabrication process for carbon stripper foils used in particle accelerators
4142
CCarbon foils are widely used in particle accelerators to produce ion beams with high charge states. These strip-per foils are primarily deposited on a soluble substrate, (e.g. NaCl or betaine-sucrose) that is subsequently dis-solved to provide a free-standing foil. For use in acceler-ators, the free-standing foils need then to be mounted on a metallic frame, a delicate and time consuming opera-tion. In this paper, we propose an alternative fabrication process, where the foils are deposited directly onto a metallic supporting frame. The process involves the surface preparation of plain copper plates, in-situ Ar-H2 plasma treatment to enhance adhesion, deposition of the carbon film by magnetron sputtering, and removal of the copper from the central part of the supporting plate by chemical etching, to create an aperture for the passing ion beam. We describe the different fabrication steps, the quality control approach used to assess the carbon areal density, the thermal outgassing rate, and the porosity of the foils. The first beam test results using CERN-produced carbon stripper foils, obtained with Pb54+ ion beams at 4.2 MeV/u at LINAC 3, are presented.
Paper: THP4115
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-THP4115
About: Received: 13 May 2026 — Revised: 19 May 2026 — Issue date: 22 May 2026
THP4301
FRIB accelerator improvement projects to mitigate beam losses in post-stripper linac
4153
The Facility for Rare Isotope Beams (FRIB) is planning four Accelerator Improvement Projects (AIPs) during a two-month summer shutdown to mitigate beam losses induced by the stripper. The motivation for this project has been described in previous publications. The implementation of these projects is required to accelerate multiple-charge-state heavy-ion beams simultaneously as beam power on target ramps up. These projects require modification of approximately 30 meters of beamline within the FRIB tunnel and include installing larger-bore magnets and beamline components before and after the liquid lithium stripper, implementing new second-harmonic cavities, replacing the dipole chamber with a high-heat-load-rated version at Folding Segment 1, and installing new quadrupole magnets at Folding Segment 2. Effective integration of design, technical device fabrication, installation, and commissioning within a limited shutdown window requires close coordination among multiple engineering and physics teams. This paper presents the planning methodology, execution strategy, and planned performance outcomes of these upgrades to manage concurrent accelerator improvement projects within a constrained maintenance schedule.
Paper: THP4301
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-THP4301
About: Received: 11 May 2026 — Revised: 17 May 2026 — Accepted: 19 May 2026 — Issue date: 22 May 2026
THP4303
Technology maturation for the LANSCE Accelerator Modernization Project (LAMP)
4157
The LANSCE accelerator is extraordinarily flexible in its ability to simultaneously accelerate both H+ and H- beams, and provide concurrent beam delivery to five independent user stations. LANSCE has been in operation for more than 50 years, and many of the accelerator structures, such as the Cockcroft-Walton injectors and drift-tube linac tanks, are original. To address end-of-life concerns and position the facility for extended operation into the future, the LANSCE Accelerator Modernization Project (LAMP) encompasses replacement of the upstream portions of the LANSCE accelerator, from the H+ and H- ion sources through the end of the drift-tube linac. In order to meet beam delivery requirements with modern equivalent systems, elements of the LAMP design require technical maturation. This paper describes the Critical Technology Elements (CTEs) in the LAMP conceptual design, presents the design elements requiring additional development, and discusses the maturation plan and schedule.
Paper: THP4303
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-THP4303
About: Received: 07 May 2026 — Revised: 17 May 2026 — Accepted: 18 May 2026 — Issue date: 22 May 2026
THP4307
Commissioning status of the H- ion source for the LANSCE Accelerator Modernization Project
4160
The LANSCE Accelerator Modernization Project (LAMP) will replace the front-end of the existing LANSCE accelerator, from ion sources through the end of the 100-MeV drift-tube linac. LAMP requires higher peak H- beam currents, and longer lifetimes, than provided by the existing LANSCE H- ion sources. The project is currently constructing an SNS multicusp cesiated source design with an internal RF antenna. This paper discusses the H- source performance requirements for LAMP, and progress towards assembling, commissioning, and operating an SNS-type source at the LAMP RFQ Test Stand (RFQTS).
Paper: THP4307
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-THP4307
About: Received: 12 May 2026 — Revised: 19 May 2026 — Accepted: 20 May 2026 — Issue date: 22 May 2026
THP5005
Recent developments of BLonD for new large scale accelerator facilities
4172
The Python-based Beam Longitudinal Dynamics (BLonD) simulation suite is an open-source framework for modelling the motion of charged particles in circular accelerators. BLonD has been in use since 2014 and is utilised successfully at several accelerator facilities such as J-PARC, ISIS, and CERN. Furthermore, BLonD is applied for the design of new synchrotrons such as the Future Circular Collider (FCC) and the Muon Collider. Both projects demand more complex simulations, as effects like strong synchrotron radiation or wake fields due to counter-rotating beams become important. In recent years, the BLonD community has also called for an improved user interface to ease the creation of input files for the simulations. This publication presents the latest software developments for BLonD. A redesigned, highly modular software architecture and improved user interface are currently being implemented, which simplify the creation of complicated relationships between physical phenomena. Preliminary testing and user feedback show improved scalability and flexibility, enabling the efficient development of particle-tracking simulations for next-generation accelerators, while facilitating the analysis of existing synchrotrons.
Paper: THP5005
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-THP5005
About: Received: 30 Apr 2026 — Revised: 20 May 2026 — Issue date: 22 May 2026
THP5301
Simulation of intrabeam scattering with nonlinear damping and diffusion in SciBmad
4180
In many modern accelerators, intrabeam scattering (IBS) leads to measurable changes in a beam’s dimensions during operation. For a Gaussian beam, there are many well-known methods to calculate the growth rates. However, while growth rates are very useful, they generally do not provide insight into how IBS interacts with effects beyond linear dynamics. To avoid this limitation, we apply IBS kicks, with both damping and diffusion components, to macroparticles during element-by-element tracking. These kicks are derived from first principles and are chosen to give the same growth rates as traditional methods for a Gaussian beam, with no special form assumed for the covariance matrix of the distribution. The beam generally becomes non-Gaussian during tracking, but the kick is nevertheless approximated by that of a Gaussian beam with the same covariance matrix. This method of IBS simulation has been implemented in SciBmad, allowing for analysis of IBS effects in beams with nonlinear spin-orbit dynamics, synchrotron radiation, beam-beam interactions, and more. Furthermore, tracking with IBS kicks is parallelized on both the CPU and the GPU.
Paper: THP5301
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-THP5301
About: Received: 12 May 2026 — Revised: 19 May 2026 — Issue date: 22 May 2026
THP5302
Differentiable, CPU-/GPU-Parallelized, Symplectic Spin-Orbit tracking in SciBmad
4184
SciBmad is a new software library for accelerator simulation and design. Three key pillars which drove the development of SciBmad’s tracking code are full differentiability (forwards-, backwards-, and Taylor-mode), high performance, and strict symplecticity. Differentiable integrators enable the trivial extraction of lattice functions and their higher-order generalizations, facilitate the use of machine learning tools, and make optimizations more efficient. The integrators have also been heavily optimized for performance, with SIMD parallelization on the CPU and GPU parallelization for various hardwares. Finally, SciBmad uses Yoshida’s symplectic schemes to integrate the fully nonlinear Hamiltonian for magnetic multipoles, RF cavities, and combinations thereof, including implicit symplectic integration where required. All elements allow for spin tracking, which is guaranteed to be orthogonal due to the generality of Yoshida’s scheme. Additionally, synchrotron radiation can be turned on in all elements. In this case, the use of a symplectic scheme guarantees that all damping results from the synchrotron radiation and not from numerical errors due to non-symplectic integration.
Paper: THP5302
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-THP5302
About: Received: 13 May 2026 — Revised: 20 May 2026 — Accepted: 20 May 2026 — Issue date: 22 May 2026
THP5306
Matching of multiple energy beamlines for the CEBAF energy upgrade
4196
It is currently planned to increase the energy of the CEBAF recirculating linear accelerator to 22GeV by adding two new recirculating arcs that contain multiple new energy passes. These new passes at six different energies must be matched to the existing linac simultaneously, as the beam is continuous (CW), so magnets cannot be ramped. This paper studies propagating several energies in the same beam pipe with a line of quadrupoles acting on all of them simultaneously, with the goal that the combined effect produces a match for each energy. Computer optimisation of the performance this system under various constraints (beamline length, number of energies) is studied.
Paper: THP5306
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-THP5306
About: Received: 29 Apr 2026 — Revised: 12 May 2026 — Accepted: 15 May 2026 — Issue date: 22 May 2026
THP5316
Simulation and analysis of high-energy beam transport lines at LANSCE
4203
The Los Alamos Neutron Science Center (LANSCE) target stations require reliable beam quality to carry out experiments under optimal conditions. Maintaining the bunch structure through the beam transport from the 800-MeV Linac to the target stations is crucial. Currently, beam transport tuning is the primary tool to control the beam, although multiple simulation tools are being developed as ones to model the beamlines. The high-energy beamlines (HEBT) are simulated with accelerator physics codes such as Elegant and MAD-X. These models are continuously improved by incorporating key beam characteristics and lattice elements. They are benchmarked against experimental data where diagnostics are available. We are improving these tools to better understand beam optics and conduct studies aimed at optimizing beam performance. In this report, we present the latest simulation results supporting more predictive beam transport downstream of the 800-MeV Linac.
Paper: THP5316
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-THP5316
About: Received: 12 May 2026 — Revised: 19 May 2026 — Issue date: 22 May 2026
THP5321
Correction of the path-length coordinate in Trackcpp for accurate longitudinal tracking
4215
The Trackcpp application, developed by the Accelerator Physics Group at the Brazilian Synchrotron Light Laboratory, models synchrotron accelerators and beam transport lines to perform six-dimensional particle tracking and optics calculations. The path length, one of the coordinates, measures the difference between a particle's arrival time, in units of length, and the accelerator cumulative length. This variable is therefore fundamental for describing the interaction of radio-frequency cavities and particles. However, the current implementation leads to limitations when simulating the longitudinal motion in accelerators that operate with non-nominal rf-frequency. This work proposes a modification to the path length variable that enables accurate longitudinal tracking at arbitrary rf-frequencies.
Paper: THP5321
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-THP5321
About: Received: 13 May 2026 — Revised: 21 May 2026 — Issue date: 22 May 2026
THP5325
SciBmad: A differentiable, GPU-parallelized software library for particle accelerator design, nonlinear analysis, and machine learning
4222
We present SciBmad, a new accelerator physics software library developed to meet the needs of all accelerator design, analysis, and virtual modeling. SciBmad consists of a set of modular packages featuring fully differentiable and CPU/GPU-parallelized symplectic integrators, spin tracking and radiation, flexible and differentiable lattice definitions, nonlinear normal form analysis tools with Lie algebraic methods, batch parameter parallelization, and more. It is fully usable in Julia and easily callable from Python, making it easy to integrate it with external optimizers and machine learning frameworks. All releases of SciBmad undergo rigorous, automated testing with maximal code coverage, and all integrators are validated against PTC. With a growing list of features and contributors, SciBmad aims to be a powerful tool for any accelerator physics application.
Paper: THP5325
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-THP5325
About: Received: 13 May 2026 — Revised: 18 May 2026 — Issue date: 22 May 2026
THP5335
Magnetic field reconstruction from sparse measurements for complex geometries
4239
Precise 3D field measurements of large, complex magnet geometries are time-consuming and error-susceptible. For large magnets, it is common to record Hall probe data on a sparse grid, then use an interpolation algorithm to estimate field values at the remaining points. For common magnet geometries, such as quadrupoles and dipoles, linear interpolation often provides accurate results. However, for complex magnet geometries, this method can yield lower accuracy. In this paper, we present a method based on a locally Maxwell-consistent algorithm for sparse Hall probe measurements. Through the k-nearest neighbors algorithm, we locally fit the magnetic field with Tikhonov regularization. We test this method on a novel Compton spectrometer, capable of measuring single-shot, double-differential, energy-angle gamma spectra, ranging from 180 keV to 28 MeV. Using held-out validation, we demonstrate that we can reconstruct its magnetic fields with higher accuracy than linear interpolation and radial basis function (RBF) interpolation with cubic, thin plate spline, and quintic kernels. We also analyze the dependence of point sparsity on accuracy.
Paper: THP5335
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-THP5335
About: Received: 14 May 2026 — Revised: 20 May 2026 — Issue date: 22 May 2026
THP5363
An efficient symplectic model for RF cavities including transverse focusing
4278
Tracking through RF cavities is complicated due to the presence of time-varying electric and magnetic fields, which are not amenable to algorithms developed for static fields. Many simulation programs use simplified models that neglect transverse focusing even though it can play an important role at low energies. Other programs track using field maps which can be slow and potentially non-Maxwellian (and therefore not symplectic) if interpolation is needed to calculate the fields. To avoid some of these problems, presented here is an RF cavity model which is symplectic and computationally efficient. Spin tracking is included and transfer maps of arbitrary order can be computed. Additionally, DC solenoid and multipole components can easily be included. This model is an extension of the work of Rosenzweig and Serafini extended to avoid the ultra-relativistic approximation. The model has been incorporated as part of the Bmad and SciBmad ecosystems of libraries and programs.
Paper: THP5363
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-THP5363
About: Received: 14 May 2026 — Revised: 19 May 2026 — Issue date: 22 May 2026
THP5602
Analysis and research on measurement errors caused by Magnet misalignment in energy analysis systems
4281
Accurate evaluation of the beam energy and energy spread plays a crucial role in the commissioning and operation of electron accelerators. The energy analysis (EA) system, consisting of a dipole with associated upstream and downstream drift sections, is widely applied in accelerator facilities due to its structural simplicity, large measurement range, and high resolution. However, assembly errors, leading to offsets or tilt angles between the input beam and the designed system axis, are inevitably introduced during engineering implementation. Such misalignment necessarily affect the accuracy of the measurement results of the EA system, and the impact may be even more significant for low-energy e-beams with the energy of a few MeV. In this context, based on the low-energy injector experimental platform currently under construction, the misalignment induced errors in the dipole-based EA systems are analyzed in depth, and potential compensation methods are explored. The study aims to provide both theoretical support and practical guidance for optimizing system alignment and improving measurement precision.
Paper: THP5602
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-THP5602
About: Received: 11 May 2026 — Revised: 20 May 2026 — Issue date: 22 May 2026
THP5605
Closed orbit and realignment in the CSNS RCS
4285
Closed orbit distortion (COD) is a critical factor affecting accelerator performance, and realignment serves as an effective measure to mitigate COD and reduce beam loss. The Rapid Cycling Synchrotron (RCS) of the China Spallation Neutron Source (CSNS) currently suffers from significant beam orbit distortion, particularly in the horizontal plane, which limits its operational efficiency. To address this issue, a systematic analysis was conducted using the MADX accelerator physics simulation program, based on the alignment measurement data obtained in the summer of 2025. Through evaluation of alignment errors and comparison of different adjustment schemes, an optimized realignment strategy was proposed, involving transverse adjustments of four quadrupole magnets. Theoretical simulation results indicate that after realignment, the horizontal orbit distortion can be reduced by approximately 2 mm, and the vertical distortion by about 4 mm, leading to a significant improvement in overall orbit smoothness. Subsequent beam tests further validated the effectiveness of the strategy. The horizontal orbit was reduced by approximately 6 mm, and the vertical orbit by about 2 mm, compared with the pre-alignment state. This study fully confirms the critical role of realignment in optimizing beam orbit performance.
Paper: THP5605
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-THP5605
About: Received: 12 May 2026 — Revised: 20 May 2026 — Issue date: 22 May 2026
THP5609
Dynamic aperture optimization based on the convexity of third-order resonance driving term variations
4291
Reducing the longitudinal variation of third-order resonance driving terms (RDTs) is much more effective in enlarging storage ring dynamic aperture (DA) than minimizing third-order one-turn RDTs. Recently, we proved the convexity of the quantitative expression for third-order RDT variations. Then, an efficient numerical method for DA optimization was developed, where a high-quality initial population for an intelligent algorithm is generated with a Gaussian distribution based on this convexity. In this paper, we study the impact of the variance of the Gaussian distribution on the optimization performance of this method. It is found that the method shows good optimization performance for small variances, and that the performance remains robust even at a very small variance. In addition, different intelligent algorithms perform well with a small Gaussian variance.
Paper: THP5609
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-THP5609
About: Received: 15 Apr 2026 — Revised: 15 May 2026 — Accepted: 16 May 2026 — Issue date: 22 May 2026
THP5617
Multiparticle beam dynamics of ELEBT integrated with upgraded RFQ in LINAC4
4312
Electrostatic low-energy beam transport* (ELEBT) section as a part of future upgradation proposal in LINAC4 at CERN, is proposed to handle 45 keV H- ion beam with 70 mA max beam current. The design allows maximum input rms normalized emittance of 0.5 π mm mrad without significant growth. Dual einzel system is incooperated in deaccelerating-accelerating (DA) mode to control beam blow up within 70% of beam pipe aperture. The ground electrode of these einzel systems also houses radio frequency electrodes for beam chopping. It chops the beam as per requirement of upgraded radio frequency quadrupole** (RFQ). The transverse and longitudinal beam optics is studied for the full system of ELEBT + RFQ. It is also validated theoretically using multi particle beam analysis. We achieved beam transmission more than 95% with all emittances well in control. The design details with respect to field computation and beam dynamics will be presented.
Paper: THP5617
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-THP5617
About: Received: 13 May 2026 — Revised: 20 May 2026 — Issue date: 22 May 2026
THP5633
Optimizing Momentum Aperture in Korea-4GSR via Higher-Order Chromaticity and W-function Analyses
4336
Recent upgrades of synchrotron light sources aim to achieve ultralow emittances, requiring strong magnet strengths that inevitably lead to severe nonlinear effects. Consequently, securing a sufficient Touschek lifetime has become a critical challenge for storage rings, including the Korea-4GSR. In this study, we performed systematic scans of tune and chromaticity to identify optimal working points and characterize lattice properties in the presence of nonlinearities and errors. Through these scans, we observed a distinct dependency of the Touschek lifetime on chromaticity settings. We explain the reason for the optimal chromaticity range by analyzing Momentum-Dependent Tune Shift (MDTS) curves and higher-order chromaticity effects. Nonetheless, directly optimizing the lifetime is computationally intensive because it requires calculating the momentum aperture along the entire ring. Hence, to overcome this challenge, we propose an efficient indirect optimization method based on the analysis of W-function fluctuations.
Paper: THP5633
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-THP5633
About: Received: 18 May 2026 — Revised: 21 May 2026 — Issue date: 22 May 2026
THP5639
Design concept of ceramic chambers at the J-PARC RCS: an analytical perspective
4353
Ceramic chambers are essential for rapidly accelerating high-intensity beams at the J-PARC RCS, as they mitigate the effects of eddy currents on the chambers. An analytical perspective could provide valuable insight into the design of ceramic chambers, though computer simulations and demanding measurements need to certify the estimates. The identity of bending magnets, including chambers, is a key to reducing beam losses at the injection area of the RCS.
Paper: THP5639
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-THP5639
About: Received: 15 Apr 2026 — Revised: 15 May 2026 — Accepted: 16 May 2026 — Issue date: 22 May 2026
THP5666
One possible approach for intrabeam scattering calculation of arbitrary phase space distributions
4402
Traditional analytical models for intrabeam scattering (IBS) typically assume a Gaussian beam distribution in phase space. In this paper, we present an extended analytical IBS model that employs Hermite-Gaussian polynomials as basis functions to calculate the IBS diffusion coefficient for arbitrary phase space distributions. The generating function method is adopted to simplify the relevant calculations into a numerically solvable integral form. This approach retains the efficiency inherent to analytical models while ensuring calculation accuracy for non-Gaussian beam distributions.
Paper: THP5666
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-THP5666
About: Received: 15 Apr 2026 — Revised: 29 Apr 2026 — Accepted: 15 May 2026 — Issue date: 22 May 2026
THP5677
Preliminary analysis of transient beam-loading effects in electron storage rings with a 3rd harmonic cavity
4412
In a 4th generation electron storage ring, harmonic cavities are often employed for increasing bunch length and beam lifetime. Effective bunch lengthening can be achieved when the first derivative of total accelerating voltage is near zero. However, the accelerating voltage fluctuation due to transient beam-loading (TBL) effect can affect the bunch lengthening in the harmonic cavity system. Therefore, we utilize both a Haissinski equation solver and a macroparticle tracking code to predict equilibrium beam distribution under TBL effects. The equilibrium longitudinal beam distributions obtained from both approaches are presented and cross-validated for different fill patterns.
Paper: THP5677
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-THP5677
About: Received: 07 May 2026 — Revised: 21 May 2026 — Issue date: 22 May 2026
THV4001
Simultaneous acceleration of two ions with unequal mass-to-charge ratio in a synchrotron
4416
In this contribution, we report on the successful simultaneous acceleration of a beam composed of two different ions with unequal mass-to-charge ratio within the same cycle of the heavy ion synchrotron SIS18 at GSI. While acceleration of multiple charge states of a single ion species has been accomplished in linear accelerators, in a synchrotron this has never been done before to the knowledge of the authors. In a proof-of-principle experiment, low intensities of 56Fe25+ and 209Bi68+ were successively injected with horizontal multi-turn injection. Using two RF cavities, each ion species was then independently captured and accelerated in the same magnetic fields at its respective revolution frequency, the bunches of the lighter ion continuously overtaking those of the heavier ion. Such a beam composed of different ions has potential applications in particle therapy, plasma physics, nuclear physics, and materials research. The distinct revolution frequencies make this scheme attractive whenever independent control over the extraction of both ions is desired.
Paper: THV4001
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-THV4001
About: Received: 08 May 2026 — Revised: 19 May 2026 — Accepted: 21 May 2026 — Issue date: 22 May 2026
THV5302
Using Neural-Network ansatz for the generating function in the Hamilton-Jacobi equation to obtain symplectic transfer maps for elements with any magnetic field configuration
4427
We present a novel method to generate a symplectic transfer map for any beamline element defined by its magnetic vector potential, even when it is known only on a 3D grid. The method uses a neural network (NN) as an ansatz to solve the Hamilton-Jacobi (HJ) equation for the unknown generating function of the second kind. This generating function is chosen to connect the solution of a simpler system with an exact analytical solution (e.g., an ideal hard-edge quadrupole) to the system with a more complex field configuration (e.g., a quadrupole with an Enge fringe field profile). This design dramatically reduces the learning burden on the NN. The learned generating function defines the trajectories and the element's symplectic transfer map via implicit equations for the particle's position and explicit equations for its momenta. The implicit equations are typically solved to machine precision in just a few iterations using Newton’s method combined with automatic differentiation capability of the NN. The method's accuracy can be conveniently estimated by how well the NN solution satisfies the original Hamiltonian. We validate the method with 1D and 2D examples for drift space, hard-edge quadrupole, and quadrupole with Enge fringe field profile.
Paper: THV5302
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-THV5302
About: Received: 16 Apr 2026 — Revised: 16 May 2026 — Accepted: 21 May 2026 — Issue date: 22 May 2026
THV5303
A hybrid physics and data-driven modeling framework for accelerators with automatic differentiation
4433
In modern accelerator modeling, many lattice components can be accurately described using established first-principles physics. However, certain intricate effects, such as complex boundary conditions, collective interactions, and self-fields, remain difficult to model reliably and efficiently from theory alone. At the same time, high-resolution beam position and profile measurements provide rich information about these poorly understood dynamics. In this paper, we present a hybrid modeling framework with built-in automatic differentiation, designed to seamlessly integrate physics-based lattice models with data-driven representations of complex effects. This approach improves predictive accuracy, enables gradient-based optimization, and offers a practical path toward more faithful digital twins of accelerator systems.
Paper: THV5303
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-THV5303
About: Received: 11 May 2026 — Revised: 19 May 2026 — Accepted: 21 May 2026 — Issue date: 22 May 2026
THV5602
Universal representation of chromatic aberration in electron beam optics
4437
We present a novel unified approach to the expression and correction of electron beam chromatic aberrations, which comprehensively covers optical systems of both a single-pass beam transport line and a circular accelerator satisfying periodic boundary conditions. In an electron circular accelerator, linear chromaticity has been utilized to express the first-order difference in beam focusing caused by the electron energy deviation, which can be computed by a well-known formula using a beam envelope function (Twiss parameters). However, this conventional formulation is incompatible with non-periodic beam transport lines, such as XFELs driven by linacs and the final focus system of linear colliders. We address this discrepancy by deriving a generalized formula that seamlessly connects the two different accelerator topologies. Our representation not only reproduces the well-known ring chromaticity but also provides a consistent and practical definition of chromatic aberrations for a single-pass transport line and their correction methods. This presentation outlines one approach to resolving this apparent contradiction and the universal formula to express chromatic effects.
Paper: THV5602
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-THV5602
About: Received: 12 May 2026 — Revised: 18 May 2026 — Accepted: 21 May 2026 — Issue date: 22 May 2026
FRI5T01
Beam dynamics in the SNS Linac and Beam Test Facility
4442
The Spallation Neutron Source Linear accelerator is the highest power superconducting hadron linac in the world. Along with this distinction comes the significant complication of deposited power from beam loss, exacerbated by the fact that the linac transports H-. This paper summarizes our understanding of beam loss in the SNS linac and highlights research being done to improve that understanding. The question of beam loss due to halo has motivated development of a detailed model fidelity project at the SNS Beam Test Facility, which includes unique phase space diagnostics for 4D-6D distributions, and high-dynamic-range 2D distributions.
Paper: FRI5T01
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-FRI5T01
About: Received: 13 May 2026 — Revised: 20 May 2026 — Accepted: 21 May 2026 — Issue date: 22 May 2026
FRO5T01
The detection of the fixed lines in four-dimensional phase space
4448
One-dimensional resonances creating fixed points and islands in the two-dimensional phase space have long been recognized as crucial for the diffusion of particles in high-intensity bunches. Coupled resonances are also highly relevant, but their dynamics is more difficult to grasp as it happens in a four-dimensional phase space. Following a conceptual and theoretical investigation, a detailed experimental campaign has been carried out in the CERN SPS to investigate the existence of the four-dimensional fixed lines. The experimental investigation has been exceptional as it required an extreme control of all accelerator parameters. We report here the difficulties encountered and the main findings, their impact, and possible application.
Paper: FRO5T01
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-FRO5T01
About: Received: 10 May 2026 — Revised: 20 May 2026 — Accepted: 21 May 2026 — Issue date: 22 May 2026
FRO5T02
Approximate invariant analysis - an efficient framework for nonlinear beam dynamics
4453
We present an efficient nonlinear beam dynamics analysis framework -- Approximate Invariant Analysis (AIA) -- which is based upon the construction of approximate invariants [Y. Li, D. Xu, and Y. Hao, Phys. Rev. Accel. Beams 28, 074001 (2025)] and the extraction of the betatron frequency using the Poincar\'e rotation number [S. Nagaitsev and T. Zolkin, Phys. Rev. Accel. Beams 23, 054001 (2020)]. The method is demonstrated using the National Synchrotron Light Source II (NSLS-II) storage ring as an example.
Paper: FRO5T02
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-FRO5T02
About: Received: 11 May 2026 — Revised: 20 May 2026 — Accepted: 21 May 2026 — Issue date: 22 May 2026
FRO6M03
Advancing accelerator science through Data-Intensive research and training
4469
The Liverpool Centre for Doctoral Training for Innovation in Data Intensive Science (LIV.INNO) continues to make significant progress in developing precision diagnostics for accelerator facilities. This talk presents recent results from four projects that collectively demonstrate how data-intensive methods, advanced modelling and modern instrumentation can enhance measurements under challenging conditions. It will be shown how detailed studies into detector dead time, after-pulsing and timing for the LHC Longitudinal Density Monitor provide quantified error budgets and mitigation strategies that improve satellite and ghost bunch measurements; how a comprehensive evaluation of multimode-fiber imaging techniques offers practical guidance on model selection, robustness and achievable accuracy for radiation-tolerant transverse profile diagnostics; how measurements of optical transition radiation (OTR) from low-energy electrons can be used to establish clear dependencies on target roughness and incidence angle, and how this allows experiment optimization; how the LHC Beam Gas Curtain has developed into a reliable, minimally invasive beam monitor, used for monitor calibration and machine optimization. In addition, this talk will also give an overview of the comprehensive LIV.INNO training, its recent and forthcoming events, and show how structured skills development and collaboration across science, healthcare, industry and sustainability drive innovation.
Paper: FRO6M03
DOI: reference for this paper: 10.18429/JACoW-IPAC2026-FRO6M03
About: Received: 13 May 2026 — Revised: 20 May 2026 — Accepted: 21 May 2026 — Issue date: 22 May 2026