Compact SRF industrial linacs can deliver beam powers exceeding 500 kW within the 10 MeV regulatory limit that is difficult to achieve with normal-conducting linacs in a constrained footprint. Although SRF technology was historically too costly and complex for widespread industrial deployment, the advent of conduction cooling has enabled compact, stand-alone SRF systems suitable for both industrial and research applications. However, the limited cooling capacity imposes stringent requirements on beam parameters, including essentially zero beam loss on the SRF cavity walls. This, in turn, demands precise control of the injected beam energy and, critically, high-quality bunching with negligible inter-bunch particles. In collaboration with Fermilab, we developed a CW normal-conducting RF injector featuring a gridded RF gun integrated with the first cell of a copper booster cavity to meet these requirements. This paper presents the complete development of the booster cavity, covering beam dynamics optimization, RF and thermomechanical design, engineering implementation, fabrication, and bench measurement.

This talk reports on the design, fabrication, and beam testing of a novel 2 MeV Ku-band (15.14 GHz) traveling wave electron linear accelerator developed by RadiaBeam Technologies for a battery-powered, hand-portable X-ray generator intended for field radiography and non-destructive testing (NDT). The goal is to replace hazardous isotopes, such as Ir-192, Cs-137, and bulky betatrons with a compact, adjustable, and safer radiation source. The system achieves dramatic miniaturization by combining several innovations: use of a 250 kW peak power air-cooled magnetron for reduced accelerator size while maintaining sufficient beam energy; a split accelerating structure fabrication method, machining both halves of the structure in one piece to eliminate the need for post-brazing tuning, reduce manufacturing errors, and improve vacuum conductance; and an ultra-compact solid-state Marx modulator, weighing ~1.2 kg, operable from two Li-Ion batteries.

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.

Tong Chen* (RefleXion Medical Inc.) Liang Huo, Tong Li, Hao Tao, Zhen Feng, Liang Hu, Lin Zhou, Yongtao Liu* (Chengdu Elekom Vacuum Electron Technology Co. Ltd) Beam energy is an important parameter of linear accelerator. Compact linacs for medical or industrial applications are usually not equipped with beam monitors. The commonly used methods are “half value layer” (HVL) in industrial and “Percentage Depth Dose” (PDD) in medical to evaluate the beam energy of linac. However, these methods are not easily and accurately carried out, the HVL method needs big and heavy steel plates to prevent scattering x ray beams and PDD method need standard beam position and expensive 3d water tank to measure the beam energy. Most importantly, those methods cannot measure electron beam energy, but the photon distribution generated through Bremsstrahlung. This article introduced a method to measure and characterize the average electron beam energy when hitting the target by combining the external measurements and simulation beam profile results under different deflection magnetic field generated by steering coils. This method not only gives confidence in developing and operating the medical equipment but also reveals relation between beam energy and RF power settings. In addition, this paper provides energy and dose output variation across the RF pulse. This data provides guidance for proper setting of gun pulse width and timing.

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.

A compact X-band 2 MeV electron linear accelerator (linac) has been developed for on-site inspection applications, addressing the limitation of hundreds-kV X-ray sources in fully penetrating dense objects during field operations. The linac system comprises three modular units, each weighing less than 65 kg, enabling manual transport by operators without specialized equipment. This paper presents the design principles, comprehensive testing results, and field deployment outcomes of this compact linac. The system demonstrates superior penetration capability, operational flexibility, and reliability in industrial environments.

Electron linear accelerators(linacs) have been widely used in industrial Non-Destructive Testing (NDT) and cargo scanning for decades, exploiting their X-ray radiography features. The focal spot size is a critical parameter of an X-ray source, where a smaller focal spot size generally yields higher image resolution. To enhance system image resolution, Chengdu Elekom Vaccum Electron Technology Co. Ltd has developed a series of small focal spot linacs for industrial and cargo scanning applications. These linacs feature focal spot size bellow 1 mm, with some type achieving sub-0.5 mm performance. After rigorous testing in laboratory and field environments, they have demonstrated high dose rates and extended operational lifetimes. This paper will provide a detailed analysis of these linacs' performance.

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.

At MedAustron, a synchrotron-based cancer therapy center located in Austria, Optical Emission Spectroscopy (OES) has proven to be an effective technique for monitoring ion source stability, offering a non-invasive alternative to traditional beam diagnostic devices such as Faraday Cups (FCs). Measurements were performed at the MedAustron injector on one of the three identical Electron Cyclotron Resonance Ion Sources (ECRIS), used for non-clinical research. For carbon ion beams, a clear correlation was observed between intensity variations in emission lines of neutral and ionized atoms in the visible range and extracted current instabilities measured on the FC. In this work, we present a study on the correlation between OES and extracted current measurements for proton and helium ion beams as a function of source parameters. Additionally, plasma characterization via OES was carried out to determine plasma parameters such as electron density and temperature via the line ratio method using the YACORA Collisional Radiative (CR) model. The results of this measurement campaign show that the applied methodology is a valid tool for monitoring source stability in parallel with clinical treatment, enabling faster detection of source instabilities and ultimately reducing downtime and speeding up low intensity investigations.

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.

This work details the qualification of a semi-industrial 10 MeV, 5 kW pulsed electron Linear Accelerator (Linac) facility, following critical maintenance on the modulator. The accelerator operates using a thermoionic emission source and a traveling-wave accelerating structure. The maintenance involved replacing a damaged Pulse Forming Network (PFN) component. The objective of this qualification process was to verify that the accelerator system meets its original operational specifications and performance parameters after the critical intervention, to ensure the stability, reliability, and dose delivery accuracy of the electron beam for its intended applications, which are typically the sterilization of medical devices.

This work presents Particle-in-Cell (PIC) simulations using WarpX [1] to study neutral beam injection (NBI) [2] physics in Wisconsin HTS Axisymmetric Mirror (WHAM) [3-5]-class beamlines as part of a DOE INFUSE collaboration between Realta Fusion and Lawrence Berkeley National Laboratory. The goal is to develop a self-consistent model that couples beam extraction, gas neutralization, re-ionization, and space-charge compensation. The neutralization model is verified against an analytic matrix formulation for charge-state evolution, and the accelerator model is benchmarked against a published WHAM-relevant positive-ion NBI configuration. WarpX reproduces the single-aperture extracted current and captures the reference downstream beam divergence. The coupled simulation further shows that primary electrons generated by impact ionization reduce the beam potential by about 80%, identifying the dominant space-charge neutralization mechanism. These results establish a benchmarked positive-ion NBI modeling workflow for future multi-aperture WHAM simulations and advanced negative-ion or photo-neutralized beam concepts.

Techniques for generating light with particle accelerators have so far proven difficult to industrialize. Accelerator-based light sources are typically housed at universities and national laboratories, which prioritize fundamental scientific discovery over economic and operational considerations like cost efficiency and 24/7 consistency. By contrast, EUV lithography in semiconductor manufacturing relies on laser-produced plasma (LPP) sources - a dependable but mature technology whose limited output power and inability to operate at shorter wavelengths constrain the industry. An accelerator-based EUV light source could be transformative for the industry, but efforts to date have yet to yield a practical solution. This talk reviews past and ongoing attempts to develop accelerator-based light sources for semiconductor manufacturing and introduces a concept under exploration at SLAC National Accelerator Laboratory – the isochronous induction-cell storage ring - which may enable coherent emission of EUV light via steady-state microbunching (SSMB).