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.

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.

In late 2024, the vibration monitoring system at the Taiwan Photon Source (TPS) was upgraded to enhance stability and usability. The system now includes beamline-floor measurement points and a central measurement center for station management, data export, automated reporting, and web-based access to real-time vibration levels and spectra. During more than a year of routine operation, issues such as abnormal sensor signals, DAQ faults, and station instability were encountered and resolved. The upgrade improves monitoring reliability and enhances the capability to record vibration behavior during events such as earthquakes and typhoons. This paper presents the upgraded system architecture, new analysis functions, operational experience, and examples of post-event vibration analysis.

In early 2025, Linac modulator 3 at the Taiwan Photon Source (TPS) exhibited signs of performance degradation. To reduce electrical stress and prevent an unplanned failure during user operations, BR injection feasibility was evaluated at 130 MeV, 140 MeV, and the nominal 150 MeV. Two compounding mechanisms limit low-energy injection efficiency: increased geometric emittance from the Linac, and degraded BR power supply waveform reproducibility at the earlier injection point on the ramp, which reduces the dynamic aperture. At 130 MeV, the mean BR current of 0.168 mA cannot satisfy the 5-second top-up window. At 140 MeV, a mean of 0.342 mA meets the >0.3 mA operational criterion, and this 140 MeV rescue mode maintained uninterrupted user service throughout the modulator degradation period.

A real-time waveform monitoring system has been developed for the pulsed power supplies in the injection chain of the Taiwan Photon Source (TPS). The system covers eight kicker and septum magnets spanning the Booster Ring and Storage Ring injection path. Two operational incidents involving SR Injection Septum~1 motivated its development: in both cases, waveform anomalies that were imperceptible by visual inspection led to severe injection efficiency degradation or complete injection failure. The system acquires waveforms via EPICS Channel Access, computes shot-averaged deviations from a stored reference, and compares them against physics-motivated alarm thresholds derived from dedicated machine study experiments. The thresholds are expressed as time-resolved curves that directly map waveform error to injection efficiency degradation. The system has been deployed and is currently in operation at TPS.

The PERLE project aims to construct a novel high power Energy Recovery Linac (ERL) demonstrator (5 MW) for developing and applying the energy recovery technique in a multi-turn configuration. In its final layout the machine will operate 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, allowing the study and validation of a broad range of accelerator phenomena and paving the way for future, larger scale ERLs. To achieve maximum efficiency, dedicated RF studies have been performed to dimension the RF system, focusing in particular on the external coupling of the superconducting cavities for both the injector and the ERL section. These studies enable the determination of the required RF power, and optimisation results for the two cryomodules will be presented. In addition, a cavity model together with its feedback control loop has been developed and used to evaluate the impact of transients during ERL ‘filling’. The models, simulation results, and their implications for the filling pattern will be shown. Finally, the strategy for ramping up the beam current in the machine and the associated effects on transient behaviour will be discussed.

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.

Undulators at BESSY II are routinely inspected for their impact on the machine tune and orbit, with the goal of ensuring tune and orbit feedforward tables remain fit for purpose. In particular this is necessary following modifications to the storage ring, as well as more obvious cases such as the installation of new devices and repositioning of existing devices. To that end a commissioning framework exploiting the Bluesky ecosystem has been established. Undulators and diagnostic hardware are represented through Ophyd device abstractions, and measurements are orchestrated as Bluesky plans with full metadata stored in a mongodb database with databroker. This has enabled the creation of an ID scan dataset for real time analysis during commissioning, rather than relying on post-hoc extraction of data from the Archiver for offline analysis. This work has also brought more consistency and better reproducibility of undulator scans, and provides the infrastructure required for more ambitious commissioning goals. It has also brought flexibility to commissioning scripts to take advantage of other innovations on the BESSY II machine and control environment. This paper outlines the application of this work to routine undulator commissioning and future goals to further simplify commissioning workflows.

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.

In this work, we present the use of PandABox timing module to implement position-based and time-based on- the-fly scanning to continuously acquire data at the X-ray Absorption Fine Structure (XAFS) and X-ray Fluorescence (XRF) beamline of SESAME synchrotron light source. For position-based scanning, we first developed a module that automatically partitions the user-defined energy and Bragg angle ranges into sub-intervals. Within each sub-interval, the energy-angle mapping is linearly approximated to main- tain accuracy within acceptable margins. The method then integrates the position encoding of the Double Crystal Monochromator (DCM) Bragg angle with the synchronous triggering of multiple detectors, including ionization cham- bers (ICs) and a KETEK SSD detector. For time-based scanning, PandABox is pre-configured to generate triggers at fixed time exposure time intervals. Improvements, per- formance and comparative results are also discussed in this work. Keywords: on-the-fly scanning, QEXAFS, DAQ, Pand- ABox, linear fitting, XAFS/XRF

Four Libera Beam Loss Monitors (BLMs) were installed downstream of in-vacuum insertion devices at MAX IV 3 GeV storage ring. The monitors were operated in counting mode, with the loss-detection threshold defined from measurements taken with no stored beam. The BLMs were configured to provide stable, high-dynamic-range loss detection. A series of controlled studies was performed to compare the loss signatures produced by different operational events, including beam scrape-downs, full beam dumps, full beam injections, and regular top-up cycles. The measurements show that scrape-downs generate the highest localized loss rates, while beam dumps produce almost no detectable signal at the BLM locations. Top-up injections exhibit consistent and repeatable loss patterns, providing a useful benchmark for routine operation. All events were studied with the insertion device gaps both closed and open; a significant decrease in detected losses was observed when the gaps were opened, demonstrating the strong influence of the local lattice and ID configuration on loss propagation. These results provide a baseline of understanding of local loss behaviour downstream of the IVUs, and will also provide more refined future operational procedures.

The Quench Detection Systems (QDS) are essential for protecting the LHC superconducting magnets and circuits during quench events. During the upcoming Long Shutdown 3 (2026-2030), several of these systems will undergo major renovation, including those for Individually Powered Quadrupole and Dipole magnets and the Inner Triplets. To secure the continued high performance of machine protection elements, a comprehensive reliability analysis was performed to ensure the probability of critical failures leading to months of downtime meets stringent requirements, while minimizing the impact on machine availability. Different system architectures were evaluated and compared. Optimized architectures were identified and fed back into the design, eliminating Single Points of Failure. Failure probabilities were estimated using analytical models that account for redundancy, inspection strategies, and demand frequencies. Results indicate that the reliability targets can be met both in operation and during magnet training campaigns, with and without additional power supplies, provided that reliable monitoring is in place and reacted upon. Yearly testing of the trigger connection to the quench heaters (DQHDS) is found to be sufficient.

Run 3 represents the final operational phase of the LHC before the transition to the High-Luminosity (HL) LHC era. It covers the operational years 2022 to 2026 and ends just before Long Shutdown 3, starting in July 2026. This period is defined by the successful restart of beam operation following the maintenance and upgrades during Long Shutdown 2, the establishment of a stable operational scheme enabling record-breaking integrated luminosities, and the exploration of performance limits in preparation for HL-LHC. This has all been achieved with infrastructure and equipment soon approaching two decades since first commissioning. Run 3 availability was closely monitored using CERN’s Accelerator Fault Tracking tool, which records fault source, duration, and cross-system impacts. The analysis presented here extracts lessons for HL-LHC from these fault statistics. Machine unavailability is dominated by long-duration faults arising from latent weaknesses, often introduced by recent upgrades and exposed when performance is pushed to its limits. While individual systems require targeted mitigation, there is little evidence of accelerator-wide aging. Radiation-induced faults show a strong impact, demanding specific attention for HL operation. These insights support future strategies for efficient machine exploitation.

The Future Circular Electron-Positron Collider (FCC-ee) is CERN’s leading proposal for the next generation of energy-frontier particle accelerators. At 91 km, it is ambitious in size, complexity and technical objectives. Availability is a significant challenge. Rising to this ambition requires a coordinated availability-driven design strategy. Three broad objectives are identified: (1) R\&D opportunities must be evaluated and compared across holistic metrics to enable early and informed design decisions; (2) Precise and balanced targets for availability must be defined ready for detailed system design; (3) Viable solutions to improve performance must be optimised against cost constraints to deliver efficient as well as performant solutions. Towards these objectives, this paper presents early results from ramilab, an integration-level performance-cost optimisation tool designed to evaluate, compare and optimise accelerator designs in terms of their holistic effect on machine availability and integrated luminosity.

At CERN, B-Train systems provide real-time magnetic field information to the RF and other subsystems with high precision and reliability, with less than 3 beam-hours lost per year per machine. Using the Proton Synchrotron Booster (PSB) as a case study, we describe a software performance-monitoring framework, currently in the prototyping phase, aimed at improving the absolute accuracy and trustworthiness of the measurement to help operators to proactively diagnose a variety of beam instabilities. The framework compares measurements with historical data, model-based expectations, and redundant acquisition chains to assess internal errors due e.g. to integrator drift or field marker degradation, apply the necessary corrections, or flag systems for intervention. We expect it to enhance compliance with evolving operational standards and future large-scale applications requiring automated self-diagnostics and remote maintenance.

To assure all deliverables for the Long Shutdown 3 (LS3) will be met, the Accelerator Beam Transfer (ABT) group has launched a coordinated initiative to strengthen Quality Management (QM), Project Management (PM), and Enterprise Asset Management (EAM). A harmonized QM framework and enhanced Non-Conformity Report (NCR) process enable early anomaly detection and structured follow-up across design, manufacturing, installation, commissioning, and operation. The upgraded PM methods clarify project scope and responsibilities, enhance risk and milestone tracking, and support coordination across HL-LHC Project and Consolidation deliverables. In parallel, the unified EAM strategy enhances equipment traceability through standardized asset structures, linked documentation and NCRs, and it provides a comprehensive lifecycle overview. Additionally, logistics have been strengthened via a dedicated service supporting the group. Together, these measures establish a robust framework for planning, executing, and documenting ABT projects for LS3, but also future shutdowns, as well as interventions in the accelerators during operation.