LINAC2026 - 33rd Linear Accelerator Conference

16 Aug 2026, 08:00 → 21 Aug 2026, 18:05 Asia/Seoul

Daejeon Convention Center

Hyung Jin Kim (Institute for Basic Science)

We are delighted to announce and invite you to participate in the 33rd Linear Accelerator Conference (LINAC 2026), which will take place from 16–21 August 2026 at the Daejeon Convention Center in Daejeon, Korea. The conference will be hosted by the Institute for Basic Science (IBS).

The LINAC conference series is the premier biennial gathering for the worldwide community of linear accelerator experts. It provides a unique opportunity to learn about the most recent advances in research, development, and applications of linear accelerators for both hadron and lepton beams.

In keeping with its long and successful tradition, LINAC2026 will feature a comprehensive scientific program with invited and contributed talks, poster sessions, and an industrial exhibition. A rich program of social events will complement the scientific sessions, fostering informal knowledge exchange and providing participants with the opportunity to experience Korean culture. Conference attendees will also be invited to visit the RAON heavy-ion accelerator facility, currently under operation in Daejeon.

Active participation of students and early-career researchers is strongly encouraged. A number of scholarships will be made available to support student attendance.

Industry partners and sponsors are warmly invited to contribute to the success of LINAC2026. The industrial exhibition and a variety of sponsorship opportunities will provide excellent visibility to companies and organizations involved in the design, construction, and operation of accelerators and related technologies.

We look forward to welcoming you to Daejeon in August 2026 for what promises to be a stimulating and memorable conference.

LINAC2026 - Exhibition_Participation Guideline_v4 (completed sponsors).pdf

LINAC2026 - Exhibition_Participation Guideline_v4.pdf

[LINAC 2026] Poster.jpg

Sunday 16 August

Registration

Student Poster Session

Welcome Reception

Monday 17 August

Registration

Welcome Address

Plenary Talks

1 Present status and future plans for linear accelerators in Korea

This talk presents the status of major linear accelerators in Korea: the RAON (heavy ion accelerator), the KOMAC (100 MeV proton accelerator), and the Pohang XFEL linear accelerator. Also future plans for each facility is to be presented including the energy upgrade of the RAON to 200 MeV/u (uranium) and the energy upgrade of the KOMAC to 200 MeV to study the radiation effects of semiconductor chips.

Speaker: Yeonsei Chung (Institute for Basic Science)

2 Updates on the Worldwide efforts for transmutation of spent nuclear fuel with accelerator driven systems

There is a worldwide demand for power, most recently driven by the >200 new chips fabs being built and the number of data centers being built and planned.

We need to turn to the nuclear solutions to solve these energy hungry global activities.

The problem is always the concern on the waste final disposition.

Used nuclear fuel reaches radiotoxicity equivalent to natural uranium ore in > 100,000 years Partitioning and recycling of uranium, plutonium, and minor actinides in spent fuel reduces this to ~300 years, vastly reducing the challenges associated with storage in permanent facilities
The goal is to transmute the most problematic isotopes in spent nuclear fuel: minor actinides and long-lived fission products Such a solution shifts the issue of used nuclear fuel disposition from an intergenerational issue to an intragenerational one.

Speaker: Bruce Yee-Rendon (Japan Atomic Energy Agency)

10:20 Coffee Break

Plenary Talk

3 High-dimensional beam tomography with PolariX: Experimental results from DESY and PSI

PolariX transverse deflection structures (TDS) are installed at different accelerators at DESY and PSI to enable advanced characterization of the particle beams for applications like free-electron lasers, beam-driven plasma acceleration, or advanced acceleration R&D projects. The variable streaking angle of PolariX – a differentiating capability of this TDS – allows us to apply a variety of tomographic methods for beam characterization. These methods provide insight into the behavior of particle beams by reconstructing their phase space in high dimensions, revealing information that is typically inaccessible. In this contribution, we present on overview of the experimentally acquired high-dimensional beam reconstructions from DESY and PSI. Furthermore, we show our latest developments of the applied tomographic methods including a significant improvement in measurement speed – an important step towards regular usability.

Speaker: Sonja Jaster-Merz (Deutsches Elektronen-Synchrotron DESY)

Invited Talks

4 Beam commissioning of the ESS accelerator: Results and Challenges

In 2025, the beam produced by the European Spallation Source (ESS) accelerator, a 600 m-long superconducting proton machine, first reached the beam dump. This presentation will give an overview over the results achieved during the commissioning rounds in 2025 and 2026, and the challenges remaining for high power and user operation.

Speaker: Sofia Johannesson (European Spallation Source)

5 Status of the LCLS-II-HE Upgrade

SLAC is engaged in an upgrade for the LCLS-II SC linac, the LCLS-II-HE project. The presentation should give an update of progress including summary of CM production and testing and schedule for installation and commissioning.

Speaker: Daniel Gonnella (SLAC National Accelerator Laboratory)

6 Coupled dynamics and transverse matching of intense heavy ion beams

Ion beams are extracted from the Electron Cyclotron Resonance source with an initial angular momentum. The focusing in the FRIB diver linac is provided by electric and magnetic solenoids and quadrupoles. Understanding the coupled dynamics and proper matching of the beams along the superconducting linac is critical to maintaining high-power, low-loss operation. The errors in the measured 4D rms emittances of various heavy-ion beams are highly sensitive to the quadrupole scan procedure.

Speaker: Alec Gonzalez (Facility for Rare Isotope Beams)

12:30 Lunch

Invited Talks

7 Four-dimensional phase space tomography from one-dimensional measurements of a hadron beam

One-dimensional measurements are used to infer the four-dimensional phase space density of an accumulated proton beam in the Spallation Neutron Source (SNS) accelerator. The reconstruction was performed by maximizing the distribution’s entropy subject to the measurement constraints and thus represents the most conservative inference from the data. The reconstructed distribution reproduces the measured profiles down to the noise level, and simulations indicate that the problem is reasonably well constrained. Similar measurements could serve as benchmarks for beam dynamics simulations in the SNS or hadron accelerators.

Speaker: Austin Hoover (Oak Ridge National Laboratory)

8 Simple and Stable 3-GeV Linear Accelerator in High Brilliance Synchrotron Light Source NanoTerasu

NanoTerasu is a highly brilliant synchrotron light source mainly focusing on soft to tender X-ray region. The NanoTerasu compact accelerator system with high performance consists of a storage ring with a circumference of 349 m and a 3-GeV linear accelerator with length of 110 m. The linear accelerator is designed not only for full energy injection to the storage ring, but also for future extension to soft-X ray free electron laser. The prominent feature of the injector system is a low-emittance compact rf electron gun employing transparent-grid scheme in a gridded thermionic cathode. The low-emittance beam from the electron gun is bunch compressed to 5 ps with a sub-harmonic buncher and accelerated up to 3-GeV with an S-band accelerating structure and 40 of 2 m long C-band accelerator structures. Since the commissioning of the linear accelerator started on April 2023, a 3 GeV electron beam with bunch charge of 0.3 nC and a normalized emittance of 10 micro-mrad has been supplied to the storage ring. This system, which is compact and simple configuration, yet produces a highly brilliant and stable electron beam, will be a good example for future electron accelerators.

Speaker: Takao Asaka (National Institutes for Quantum Science and Technology)

9 Systematic Mitigation of Intra-Beam Stripping and Distributed Beam Loss in High-Intensity H⁻ Linacs: Experimental and Operational Experience at J-PARC

Charge-exchange injection using H⁻ beam enables high-intensity proton accumulation in rapid cycling synchrotrons and storage rings. As a result, high-power H⁻ linacs are indispensable for modern pulsed neutron sources and high-energy physics facilities.
Compared with proton linacs, H⁻ linacs are intrinsically susceptible to loss induced by electron stripping. Intra-beam stripping (IBSt) is a fundamental, intensity-dependent mechanism that can dominate residual activation and is governed by phase-space distribution and focusing lattice. In addition, H$^0$ generated by stripping produce broad loss patterns sensitive to aperture constraints.
At the J-PARC linac, these mechanisms were investigated through experiments, simulations, and long-term operation. Their dependencies on lattice and apertures were quantitatively characterized, with good agreement between simulations, monitors, and radiation measurements.
Based on this understanding, a systematic mitigation strategy was established. Radiation hot spots were eliminated, and total activation was reduced by more than a factor of two, enabling stable high-power operation and providing guidance for future high-intensity H⁻ linacs.

Speaker: Yong Liu (High Energy Accelerator Research Organization)

Oral Posters

Poster Session

Tuesday 18 August

Invited Talks

10 Operational Status of the KOMAC 100 MeV Proton Linac and Pilot R&D for the 200 MeV Upgrade

The 100 MeV proton linac at KOMAC has operated since 2013, providing irradiation services for materials, biomedical, semiconductor, and nuclear/basic science through four user beamlines. The accelerator comprises a 50 keV injector, 3 MeV RFQ, and DTL to 100 MeV. Major beamlines support multidisciplinary research, semiconductor radiation assessment, and isotope production, while a white-spectrum neutron service is in pilot operation with official user service planned for 2026. A Beam Test Stand supports accelerator R&D, including machine-learning-based tuning, emittance control, and advanced phase-space diagnostics. A 200 MeV upgrade based on a normal-conducting SDTL is in preparation. The LINAC’26 conference provides an opportunity to present the operational status, beamline utilization, and progress toward the 200 MeV upgrade.

Speaker: Han-Sung Kim (Korea Atomic Energy Research Institute)

11 PIP-II PROJECT PROGRESS AND CHALLENGES

The PIP-II Project is under construction to provide the Fermilab Accelerator Complex with a new H- SRF linac and beam transfer line delivering 800 MeV protons at Booster injection at double energy and double intensity (6.7x1012 proton per 20 Hz pulse) in comparison with the present Linac.
The design goals of PIP-II Linac will be described, including delivering 1.2 kW beam power on LBNF/DUNE target, CW operation compatibility and future upgrades.
The progress of the Linac construction and the development of the Commissioning Plan will be presented.
Finally, the challenges of operating the SRF Linac to drive the Fermilab Booster will be addressed.

Speaker: Dr Olivier Napoly (Fermi National Accelerator Laboratory)

12 High intensity, high polarization electron gun for Electron–Ion Collider

Polarized electron sources are essential for accelerator facilities such as the Electron–Ion Collider and polarized positron sources, which require guns with higher voltage and bunch charge than existing polarized gun. At Brookhaven National Laboratory, we developed an inverted High-Voltage DC (HVDC) polarized photoemission gun with a Distributed Bragg Reflector superlattice GaAs photocathode and a cathode cooling system suited for future high-current operation. The gun was conditioned to 350 kV with no measurable field emission and delivered polarized electron bunch charges up to 11.6 nC, reaching the current density of 14.5 A/cm² at the source. To our knowledge, this is a record operating voltage for a polarized DC gun and a record current density for a polarized electron source. We mitigated the surface charge limit through optimized surface doping and heat-cleaning procedures and by leveraging the high accelerating gradient at the cathode. We also studied the effects of the DBR layer and laser parameters on photocathode lifetime and identified an operating regime that provides long lifetime while maintaining high polarization at 30 µA.

Speaker: Erdong Wang (Brookhaven National Laboratory)

13 Photocathode-driven injector linac design for Korea-4GSR

As part of the ongoing Korea-4GSR (Fourth-Generation Synchrotron Radiation) project, a 200 MeV electron linac is being developed based on an S-band photocathode, rather than the conventional thermionic gun approach. The gun provides high electron energy (4 MeV) and low emittance, which simplifies the design of the initial accelerating RF system, magnets, and beam transport to the booster. The basic concept of the linac builds upon the successful PAL-XFEL design and has been further optimized to support 64-multibunch generation, precise energy feedback, injection timing control, and higher charge operation. Plans for gun testing and commissioning will also be presented.

Speaker: Chang-Ki Min (Pohang Accelerator Laboratory)

14 First robotic assisted string assembly of PIP-II SSR2 cavities at Fermilab

Achieving robotic-assisted string assembly has been a longstanding objective in superconducting cavity production to improve precision, repeatability, and throughput while reducing operator-dependent variability. At Fermilab, robotic systems have been successfully deployed for the installation of individual components on SSR2 cavities inside a cleanroom environment. The single-cavity installations validated the feasibility of robotic techniques and provided confidence to extend automation to the assembly of a full prototype cavity string. Leveraging lessons learned from earlier operations, the robotic system was adapted for the string assembly. This work describes the robotic-assisted assembly process in detail, including alignment strategies for coupler flanges, torque control for bellows connections, and mitigation of particulate generation in cleanroom conditions. Performance metrics of the cryomodule are presented, together with an analysis of improvements needed for robotic assembly. The effort also represents a broader R&D initiative at Fermilab to the long-term goal of scalable SRF cryomodule production.

Speaker: Mattia Parise (Fermi National Accelerator Laboratory)

15 Automated Commissioning and Intelligent Operational Strategies for the HIAF-iLinac SRF System

High-intensity superconducting linear accelerators present significant challenges regarding efficiency and reliability during both commissioning and operation. This paper summarizes the engineering practices in full-process automated operation and maintenance implemented for the HIAF-iLinac SRF system. To address the requirements of large-scale cavity commissioning, an automated conditioning framework integrating AI-driven waveform recognition was developed, enabling 24/7 unattended operation for 96 SRF cavities. Utilizing online parallel measurement tools, over 600 critical cavity parameters were precisely calibrated, providing an essential foundation for beam commissioning. To facilitate the design and optimization of high-performance real-time control algorithms, an FPGA-based high-fidelity digital twin platform was constructed, allowing for closed-loop verification and parameter pre-tuning of advanced control strategies before engineering deployment. Regarding facility operation, a "one-key" rapid loading technology supporting both pulsed and continuous-wave modes was implemented, reducing the closed-loop recovery time after faults to within 2 minutes.

Speaker: Feng Qiu (Institute of Modern Physics, Chinese Academy of Sciences)

10:30 Coffee Break

Plenary Talks

16 Charge Selector Challenges in High Power Heavy Ion Linacs

Heavy ion linacs use charge stripping to increase accelerating efficiency. At FRIB, the charge selector intercepts unwanted charge states from their broad distribution after stripping at the energies of 17-20 MeV/u. Design of a movable collimator for high-power heavy ion beams becomes very challenging due to high volumetric power deposition, radiation damage, radioactivation, and mechanical constraints. Uranium beam, for instance, produces the average power density on the charge selector that is orders of magnitude higher than proton beams, and the radiation damage rates that heavy ions produce reach several dpa/minute. This talk will present the design challenges and our experience in the development of the FRIB charge selector.

Speaker: Alexander Plastun (Facility for Rare Isotope Beams)

Lightning Talks by Participating Industries

12:30 Lunch

Invited Talks

17 Development and First Beam Generation of A Conduction-Cooled SRF Photogun

We report the first beam produced by the world’s first conduction-cooled superconducting radio-frequency (SRF) photogun. Over the past seven years, Euclid, in collaboration with Fermilab and Argonne National Laboratory, has developed a 1.5-cell, conduction-cooled Nb3Sn SRF photogun operating at 1.3 GHz. The primary objective of this effort is to demonstrate ultra-stable electron beams for ultrafast electron microscopy and diffraction (UEM/UED) applications. Although SRF systems were historically too costly for industrial deployment, two recent advancements: Nb₃Sn coatings and conduction cooling, have dramatically reduced system complexity and operating costs. This SRF photogun can deliver true CW operation while dissipating only ~2 W of RF power, eliminating the need for a high-power RF system and significantly reducing facility footprint. It is also featured with a raised Nb3Sn backwall serving as the photocathode, removing the need for an external cathode insert. In this talk, we present the development process of the cavity and cryostat, along with its cooldown performance, Q-slope behavior, synchronization characteristics, and the first beam generation.

Speaker: Chunguang Jing (Euclid Techlabs (United States))

Oral Posters

Poster Session

Wednesday 19 August

Invited Talks

18 Post-Mortem Insights into the SNS RFQ: Implication and Paths Forward for high beam power operation

The first Radio-Frequency Quadrupole (RFQ01) at the Spallation Neutron Source (SNS) operated in both the main accelerator and the Beam Test Facility for a combined period of approximately 20 years. Over this time, the performance of RFQ01 declined significantly, with beam transmission decreasing from about 90% to 70% or less. RFQ01 is currently undergoing a comprehensive post-mortem analysis. Initial visual inspections revealed substantial erosion on the low-energy side of the vane tips. To characterize the erosion profile with high precision, a 3D microstructural surface replication was produced using an in-house, 6-inch-long mold along with full 3D CST model. Additional borescope inspections identified further vane erosion in the middle and downstream sections of the first segment. The final phase of the post-mortem study will involve full disassembly of the structure to expose the entire length of each vane for complete laser scanning. The CST 3D model will then be updated to incorporate the full erosion profile. The results of these studies will help clarify the underlying degradation mechanisms and inform implications and paths forward for reliable high beam power operation.

Speaker: Haitao Ren (Oak Ridge National Laboratory)

19 Overview and current status of the IFMIF-DONES accelerator systems

Overview and current status of the IFMIF-DONES accelerator systems is presented.

Speaker: Dr Ivan Podadera (Consorcio IFMIF-DONES España)

20 A SURVEY OF THE GLOBAL SCIENTIFIC KLYSTRON MARKET AND ITS FUTURE

The continued high-quality scientific output of many research facilities depends directly on their reliable operation and, in taking a wider view, a market that can provide a stable supply. In the late 2010s and early 2020s, market irregularities were amplified in large part because of the COVID-19 pandemic and the disruption it caused in resource availability. Though COVID-19 has been resolved for some time, the instabilities in the klystron market persist. Recently, the Spallation Neutron Source, the European Spallation Source, Argonne National Laboratory, and SLAC National Accelerator Laboratory formed a committee to assess the current state of the scientific klystron market and determine how best to stabilize it for the future. To that end, the committee decided to start with a global workshop that explicitly included not just end-users, but, importantly, klystron suppliers as well. The first “Long-Pulse and Continuous Wave (CW) Klystron Workshop” was held at the Oak Ridge National Laboratory’s Spallation Neutron Source in late September 2025. This presentation summarizes the findings, actions, and progress against those actions determined by the workshop attendees.

Speaker: John Moss (Oak Ridge National Laboratory)

21 Status of the HIAF Linacs

IMP is constructing two major projects near Huizhou. Both involve the installation of superconducting hadron linacs with equipment that has been developed by IMP over the last decade or more. The presentation should summarize progress on the two projects.

Speaker: Weilong Chen (Institute of Modern Physics, Chinese Academy of Sciences)

22 TRANSFORMING THE BNL 200 MeV H⁻ LINAC: 10³ LOWER LOSSES, 2× HIGH-CURRENT TRANSMISSION, AND 2× LOWER EMITTANCE

Abstract
The Brookhaven National Laboratory (BNL) 200 MeV Drift Tube Linac (DTL) operates at 6.67 Hz, delivering H⁻ beams for both the polarized proton program at RHIC and isotope production at BLIP. Over the past two decades, targeted upgrades—especially within the low-energy and medium-energy beam transport (LEBT and MEBT) sections—have dramatically enhanced linac performance. Beam transmission for high-current isotope production has improved by more than 100%, while transverse emittance has been halved for polarized proton operation. Moreover, beam losses have been reduced by three orders of magnitude, significantly lowering radiation levels and enabling higher current delivery. These upgrades translate into increased beam intensity to BLIP and superior quality and stability to EIC, marking a transformative step for the linac’s long-term operational reliability and scientific output.

Speaker: Deepak Raparia (Brookhaven National Laboratory)

23 High-Current Heavy-Ion Acceleration Above 100 mA in a Four-Rod RFQ

We report on the achievement of a world-record peak beam current for heavy ions through the acceleration of fully stripped carbon ions (C⁶⁺) using a 100-MHz four-rod radio-frequency quadrupole (RFQ) accelerator combined with a Direct Plasma Injection Scheme (DPIS) driven by a laser ion source.
A peak beam current of 105 mA was successfully accelerated to an output energy of 300 keV/u. The beam current was measured downstream of the analyzing magnet for charge-state selection, confirming transport and acceleration of the high-intensity C⁶⁺ beam. This result represents the highest peak current achieved to date for heavy-ion RFQ acceleration.

Beam commissioning demonstrated stable RF operation and robust beam transmission at record current levels. The accelerator performance, space-charge behavior, and operational limits are discussed, together with the implications for next-generation high-current heavy-ion injectors and accelerator-driven applications in the >100 mA regime.

Speaker: Masahiro Okamura (Brookhaven National Laboratory)

10:30 Coffee Break

Plenary Talks

24 Laser-plasma accelerator driven radiation generation and applications

Laser-plasma accelerators hold great promise for a range of radiation generation applications due to their high accelerating gradients, which can result in significant reductions in facility size and cost. They are also capable of producing electron beams with novel and tunable properties, including ultrashort bunch durations. Recent work has demonstrated several advances in secondary radiation generation, achieving high performance with stable operation over extended periods.

This talk will present an overview of recent breakthroughs in compact radiation sources based on laser-plasma accelerators at the BELLA Center, Lawrence Berkeley National Lab. Highlights include stable, high-gain operation of compact free-electron lasers over several hours (S. Barber et al., PRL 2025; F. Kohrell et al., PRAB submitted; K. Jensen et al., PRAB submitted), compact generation of directional multi-GeV muon beams (D. Terzani et al., PRAB 2025), Thomson scattering for monochromatic gamma-ray production (H.-E. Tsai et al., PRAB in prep), and advanced imaging applications using LPA betatron radiation (M. Balcazar et al., Nature Communications 2025).

Speaker: Jeroen van Tilborg (Lawrence Berkeley National Laboratory)

Invited Talks

25 Status of the NEWGAIN Project: The New Heavy Ion Injector for SPIRAL2

The NEWGAIN (NEW GAnil INjector) project is now in the construction phase at GANIL. This major upgrade, driven by the integration of the new ASTERICS superconducting ECR ion source, aims to expand the capabilities of the SPIRAL2 accelerator by enabling the acceleration of heavy ions with an $A/q$ ratio of up to 7. With this enhancement, SPIRAL2 will provide high-intensity beams ranging from protons to uranium, significantly strengthening GANIL’s international competitiveness in both fundamental research and multidisciplinary applications.
This communication provides a detailed update on the construction progress and outlines the key milestones achieved and forthcoming. The layout of the new injector features two ECR ion sources—including ASTERICS, for which the superconducting coil is currently under fabrication—and two LEBT lines. The system also includes a new RFQ, with mechanical sections currently being received at GANIL, followed by a MEBT section designed to inject the beam into the existing SPIRAL2 MEBT and subsequent superconducting LINAC.

Speaker: Frederic Chautard (Grand Accélérateur Nat. d'Ions Lourds)

26 Breaking the Cryoplant Barrier: Conduction-Cooled Nb₃Sn SRF Linacs for Industrial and Environmental Applications

Superconducting linacs have traditionally required large cryogenic infrastructures, while compact accelerators relied on normal-conducting technology. This divide is narrowing. At Fermilab’s IARC, Nb₃Sn-coated cavities operating near 4 K, combined with cryocooler-based conduction cooling and solid-state RF power, enable compact SRF linacs for high-duty-factor operation outside traditional facilities. Systems under construction target environmental remediation and medical device sterilization at approximately 10 MeV, where efficiency and life-cycle cost are critical. These machines use multi-cell elliptical cavities at 650 MHz and 1.3 GHz, operating at 7–10 MV/m under conduction cooling with industrial cryocoolers. Eliminating liquid-helium plants shifts SRF from facility-scale installations to application-oriented platforms, thereby extending superconducting technology into regimes that have not been economically viable.

Speaker: Jayakar Thangaraj (Fermi National Accelerator Laboratory)

Social Outing

Thursday 20 August

Invited Talks

27 25 years of FEL operation at FLASH (DESY)

First SASE lasing at DESY's FLASH Free-electron laser (FEL) - that time called as TESLA Test Facility FEL - was in February 2000. It was the first FEL worldwide producing SASE radiation at VUV wavelengths. Since then, over more than two decades, FLASH has provided high peak and average brilliance XUV and soft X-ray FEL radiation for photon science experiments.

In order to operate FLASH as a state-of-the-art FEL, it has been continuously refurbished and upgraded. The most recent upgrade FLASH2020+ increased the electron beam energy of the superconducting linac to 1.35 GeV and reconstructed the FLASH1 undulator beamline. The new external seeded FLASH1 will provide fully coherent radiation at up to MHz bunch repetition rate (burst). Moreover, thanks to the new APPLE-III type undulators, a full polarization control is possible. As before, FLASH1 hosts also a THz source. FLASH2 continues in SASE operation.

This paper provides an overview of FLASH's evolution from a test facility for superconducting accelerator technology to a trailblazing and innovative FEL user facility, very successfully operated for the photon science community.

Speaker: Katja Honkavaara (Deutsches Elektronen-Synchrotron DESY)

28 Compact and efficient CW electron LINACs for industrial and environmental applications

Compact, efficient and high-power sources of electrons are of growing interest for a wide range of applications including materials processing, medical device and food sterilization, wastewater and soil treatment. Electron energy from <1MeV to 10 MeV and beam power from kW to MW levels are desirable. We describe a compact modular system being developed at JLab starting with a gridded thermionic electron gun and using an initial graded-beta copper CW linac to capture and form the beam, followed by one or more beta=1 CW linac sections to increase the energy. These sections may be normal conducting or conduction-cooled superconducting cavities depending on the energy and power levels required. CW operation allows for reliable high average power at modest gradient using cost-effective, highly efficient industrial magnetrons for the RF sources. We describe the design and development of these component along with plans for an integrated system to demonstrate CW beam operation.

Speaker: Robert Rimmer (Thomas Jefferson National Accelerator Facility)

29 Intrabeam Scattering and 6D Brightness: Modelling, Measurement, and the Road to a Brighter SwissFEL electron source

Intrabeam scattering (IBS) in the SwissFEL injector has emerged as a critical performance-limiting phenomenon, manifesting as a significantly larger slice energy spread than previously anticipated. By combining detailed numerical simulations with a newly developed analytical model, we achieve excellent agreement with experimentally measured slice energy spreads, validating our approach. These results naturally prompt the question of how IBS-induced degradation can be mitigated, both in future SwissFEL operation and in next-generation facilities. Leveraging the insights gained from our study, we identify key design principles for X-ray free-electron laser (XFEL) injectors aimed at suppressing slice energy spread growth. Furthermore, guided by this improved understanding, we propose and evaluate novel operational schemes for the electron source that enhance XFEL performance in the presence of IBS.

Speaker: Thomas Lucas (Paul Scherrer Institute)

30 Technical commissioning of the ESS linac cavities for the Beam on Dump Phases

The ESS linac has been commissioned in two different operation phases operation on the 12 kW commissioning beam dump. In 2025 the linac was operated at full duty cycle in the NCL section (up to 90 MeV) and at reduced duty cycle in the SCL section (up to 870 MeV), due to limitations in the cooling infrastructure and staged implementation of LLRF functionalities. In the present phase the while linac has been operated up to its full duty cycle at 14 Hz and 3.2 ms RF pulses, showing LFD capabilities with long RF pulses in SRF structures.
This contribution summarizes the staged technical commissioning phases, presenting the conditioning experience and the setup for operation at nominal RF performances.

Speaker: Marten Koopmans (European Spallation Source)

31 Progress in the LIPAc Validation and the roadmap towards SRF Linac Beam Commissioning

The Linear IFMIF Prototype Accelerator (LIPAc), jointly developed by Europe and Japan, aims to validate the acceleration of a 125 mA deuteron beam in continuous‑wave operation up to 9 MeV. In the 2024 campaign, LIPAc achieved a major milestone by demonstrating high‑duty RFQ operation with a 119 mA deuteron beam and a duty cycle approaching 10%, marking the highest‑performance operation to date. Building on this progress, preparation for the SRF Linac commissioning has advanced steadily.
The cryomodule assembly is now on track for completion in early 2026, following the resolution of several technical challenges that had previously constrained the schedule. Subsequent integration activities—including beamline installation and the connection of electrical and cryogenic systems—will pave the way toward the first SRF Linac cooldown, targeted for late 2026 to early 2027.
This contribution highlights the key achievements of Phase B+, details the ongoing preparation for SRF Linac integration and check‑out activities, and presents the roadmap leading to the first beam commissioning of the SRF Linac.

Speaker: Keitaro Kondo (National Institutes for Quantum Science and Technology)

10:30 Coffee Break

Invited Talks

32 Development of the composite structure SRF cavities for pursuing high operational stability at IMP

The on-line operating instability of the bulk Nb superconducting cavity is mainly attributed to the following factors: Lorentz force detuning, mechanical vibration, thermal breakdown induced by the electron loading effect and the enhanced heat dissipation at defects etc. Theoretically, the copper-niobium / aluminum-niobium composite superconducting cavities have excellent potential for high thermal and mechanical stability, which can make full use of the high-gradient surface processing recipes developed for the bulk niobium cavity, the thick copper/ aluminum layer’s high thermal conductivity and rigidity, thereby enhancing the operational stability of the bulk niobium cavities. In this contribution, we present the status of development of the CuNb composite and AlNb composite superconducting cavities at IMP, including the technical challenges, the RF and mechanical test results at cryogenic temperature, etc.

Speaker: Shichun Huang (Institute of Modern Physics)

33 Operation challenges of large-scale low-beta SC cavities in heavy ion linac

The FRIB has extensive experience operating large amounts of low-beta (quarter-wave and half-wave) superconducting resonators. This talk will report overcoming challenges in supporting the SRF system with nearly 100% availability.

Speaker: Sang-hoon Kim (Facility for Rare Isotope Beams)

Student Prizes

12:30 Lunch

Invited Talks

34 Progress on Staging of laser-plasma accelerators

Multi-stage coupling of two or more laser-plasma accelerators is as a key technology for future high-energy physics applications of plasma-based accelerators, including TeV-scale collders. Single laser-plasma accelerators stages have demonstrated accelerating gradients orders of magnitude beyond conventional RF technology, high beam quality, and acceleration to 10 GeV. However, scaling to collider-relevant energies requires the efficient coupling of multiple plasma stages with beam quality preservation and minimal charge loss.
Currently, demonstrations of staging have been limited to energy gains at the ~100 MeV level, with low charge transport between the stages (Steinke, Nature 2016). At the BELLA Center, multi-stage coupling of laser-plasma accelerators at the GeV level is being investigated. This talk will present an overview of recent progress towards high quality multi-stage coupling including stable, high quality injectors, active plasma lenses, and plasma mirrors.

Speaker: Dr Aodhan McIlvenny (Lawrence Berkeley National Laboratory)

35 Experimental Generation of Extreme Electron Beams for Advanced Accelerator Applications

Published in PRL. Demonstration of experimental generation of high energy (10 GeV), ultrashort (femtosecond-duration), ultrahigh current (∼0.1  MA), petawatt peak power electron beams in a particle accelerator. These extreme beams enable the exploration of a new frontier of high-intensity beam-light and beam-matter interactions broadly relevant across fields ranging from laboratory astrophysics to strong field quantum electrodynamics and ultrafast quantum chemistry. We demonstrate our ability to generate and control the properties of these electron beams by means of a laser-electron beam shaping technique. This experimental demonstration opens the door to on-the-fly customization of extreme beam current profiles for desired experiments and is poised to benefit a broad swath of cross-cutting applications of relativistic electron beams. https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.134.085001

Speaker: Claudio Emma (SLAC National Accelerator Laboratory)

36 Simultaneous boost of electron beam energy and brightness in a plasma wakefield accelerator

(based on recently published Nat. Commun. 16, 10719 (2025)).

Demonstrating that a plasma-wakefield accelerator operating in the nonlinear regime acts as a transformer to simultaneously boost the energy and brightness of an electron bunch injected from the plasma. Using a 10-GeV drive bunch and a three-stage meter-scale plasma source, electron bunches exceeding 20 GeV with sub-percent energy spread, 2 mm·mrad normalized emittance, and multi-kA peak current were observed. Other important features including high energy-conversion efficiency, an energy transformer ratio exceeding two, and a brightness enhancement over an order of magnitude were also observed

Speaker: Douglas Storey (SLAC National Accelerator Laboratory)

Oral Posters

Poster Session

Conference Banquet

Friday 21 August

Invited Talks

37 A Very compact Inverse Compton scattering gamma-ray source at Tsinghua University

The inverse Compton scattering (ICS) source based on the collision between high-quality electron beams and laser can generate high-brightness quasi-monoenergetic γ-rays. Our labs have developed a compact MeV quasi-monoenergetic γ-ray ICS source and has successfully commissioned. The VIGAS can generate gamma ray beam with energy can be adjusted from 0.2-4.8MeV, and flux about 10^8 phones/second. A high-quality compact electron linear accelerator, which integrated S-band (gun, buncher and pre-accelerator) and X-band (main accelerator) structures, has been successfully operating with electron beams energy higher than 320 MeV within 9.7 meters. A low-level radio frequency (LLRF) system featuring high-precision synchronization has been successfully developed and has demonstrated stable operation. We have started the investigation of VIGAS applications and is currently conducting the preliminary experiments such as high energy phase contrast imaging.

Speaker: Chuanxiang Tang (Tsinghua University)

38 Low-emittance muon beam acceleration using a radio frequency quadrupole for the J-PARC muon g−2/EDM Experiment

At Japan Proton Accelerator Research Complex (J-PARC), a low-emittance muon beam based on a linear accelerator is being developed for precision measurements of the muon anomalous magnetic moment (g-2) and electric dipole moment (EDM), as well as for non-destructive imaging applications. In the low-velocity section of the muon linac, a 324-MHz radio-frequency quadrupole linac (RFQ) is employed to bunch and accelerate muons from thermal energy to 340 keV.
In this study, a muon-beam cooling and RFQ acceleration experiment is being conducted at J-PARC. Thermal muons are produced via laser ionization of thermal muonium emitted from a room-temperature silica aerogel target, electrostatically extracted to 5.7 keV, and injected into the RFQ. The muons are accelerated to 340 keV, and their longitudinal and transverse beam profiles are being characterized at the RFQ exit.
This work demonstrates an in-situ implementation of a full-scale RFQ for the world’s first muon linac in the dedicated g−2/EDM experimental area at J-PARC. The experimental concept, beamline configuration, commissioning status, and outlook toward establishing a low-emittance muon linac are presented.

Speaker: Yuga Nakazawa (High Energy Accelerator Research Organization)

39 New-type high-voltage pulse generator with wide-band rf amplifiers: The principle and application for particle accelerators

A new-type high-voltage pulse generator by means of a method of frequency-segmented power amplification was proposed and developed. A seed pulse is divided into several lines that have bandpass filters, variable delay lines, variable power attenuators, and main rf amplifiers to correct the frequency-dependent group delays and gain of the amplifier circuit and to perform fine-tuning of the pulse structure. The high-voltage pulse was finally obtained by combining them with the rf power combiners. We introduced it for the new beam chopper of low-emittance thermionic electron gun at the X-ray free-electron laser SACLA. Flat and stable pulses with a 2-ns width, a 0.8-kV height in 50-ohm impedance, and peak-to-peak flattop variation of 0.6% were successfully generated, and the system has already been in operation at the SACLA injector. It can also generate an electron beam with multi-bunch structure. Recently, we succeeded in generating double-bunch XFEL lights with a 10-keV photon energy, 0.5-mJ pulse energies each, and 8.4-ns bunch separation. This type of pulse generator will play important roles not only in particle accelerators but also in other fields such as optical lasers.

Speaker: Dr Kazuaki Togawa (RIKEN SPring-8 Center)

40 Development of MW-Level Compact P-Band Metamaterial Klystrons at CSNS

The CSNS has newly developed a metamaterial based 324 MHz klystron with R&D launched in 2021 and successful hot testing in June 2025. The metamaterial-loaded cavities enable 55% shorter structure length, and the integrated second harmonic bunching cavity achieves high efficiency， With 3 MW peak output power and 53.1% efficiency. this report shares the latest development of the metamaterial klystron.

Speaker: Zhencheng Mu (Institute of High Energy Physics)

41 The Jefferson Lab Injector Upgrade: Design, Commissioning, and Operational Performance

The Continuous Electron Beam Accelerator Facility at Jefferson Lab recently underwent a significant injector upgrade to meet the stringent beam quality requirements of upcoming physics experiments and to enhance system reliability. Key modifications include replacing the 130 kV DC photo-cathode gun with a 200 kV version and installing a new SRF booster consisting of 2-cell and 7-cell cavities. This new booster architecture accommodates a broad range of injection energies (130 keV to >300 keV) while simplifying the initial bunching and acceleration stages. The design choices and operational challenges addressed during this upgrade offer valuable insights for other electron injectors aiming to increase simplicity, flexibility, and reliability. Supporting beamline components, including Wien filters and magnets, were similarly upgraded to scale with the higher beam energy. Over the past year, the upgraded injector has met experimental physics requirements, creating beams for four experimental halls simultaneously with >85% availability. This presentation discusses the design philosophy, beam dynamics simulations, hardware performance, and operational beam characterization results.

Speaker: Dr Reza Kazimi (Thomas Jefferson National Accelerator Facility)

42 Demonstration of cavity field mapping by falling drops of liquid

Experimental mapping of the electric field of a cavity is usually through bead-pull measurements. These require quite long times to align the bead and are generally restricted to the beam axis. Here, the bead has been replaced by drops of liquid falling through the cavity. Together with efficient compression and noise reduction techniques, the method allows for fast and precise measurements. The launching position of the droplets is controlled by a motor driver, thus allowing for automated 3d-field mapping around the axis. Results from mapping a 36 MHz buncher cavity are presented.

Speaker: Xiaonan Du (GSI Helmholtz Centre for Heavy Ion Research)

10:30 Coffee Break

Plenary Talks

43 Linac Facilities for Single Event Effects Testing

Modern electronic systems are required to provide various degrees of radiation hardness against performance and lifespan degradation due to the natural environment, man-made radiation sources, and their mission or use case. Solar coronal mass ejections (CME) and galactic cosmic rays (GCR) are two sources of naturally-occurring radiation fields with sufficient flux and energy to disrupt sensitive electronic systems. Single event effects (SEE) are a primary cause of failures in electronics due to energy deposited by high energy ions. Accelerator-based sources of ion irradiation are now commonly used to explore device interactions with ions of 10’s MeV/AMU kinetic energies. With the evolution of requirements from the electronics community to ions in the 100’s MeV/AMU to GeV/AMU energy regime, new accelerator architectures are being considered. Linac-based facilities offer several advantages over other architectures. In this talk we will discuss the requirements and opportunities for accelerator-based radiation sources for SEE testing, and the tradeoffs between various architectures. Current and proposed linac-based facilities will be presented and discussed.

Speaker: Steven Lidia (Facility for Rare Isotope Beams)

Closing Talk

Closing

Facility Tour