timing
MOYD1
Review of nonlinear resonances in acclerators and storage rings
13
Review of nonlinear resonances in accelerators and storage rings; including a discussion of chaos, particle diffusion and dynamic aperture
Paper: MOYD1
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-MOYD1
About: Received: 23 Apr 2025 — Revised: 05 Jun 2025 — Accepted: 06 Jun 2025 — Issue date: 05 Nov 2025
MOYD2
Liquid lithium charge stripping technology: Achievement and lessons learned
19
Liquid metal technology is key to the next-generation high-power hadron facilities. Following early R&D collaboration between Argonne National Laboratory and Michigan State University, FRIB pioneered the technology of liquid lithium thin film and is the first in the world applying such technology in accelerator operations. FRIB uses a liquid lithium film for the charge stripping of high-power heavy-ion beams, enabling FRIB to achieve world’s highest power uranium beam on target. Liquid lithium technology has been successfully applied to the liquid lithium charge stripper for FRIB operations, offering a superior choice for charge stripping of high-power heavy ion beams including uranium. Valuable experience has been gained in the performance and maintenance. This talk focuses on operational experience, lessons learned and future improvements.
Paper: MOYD2
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-MOYD2
About: Received: 01 Jun 2025 — Revised: 02 Jun 2025 — Accepted: 02 Jun 2025 — Issue date: 05 Nov 2025
MOCD3
Observations and efforts to reduce sudden beam loss at SuperKEKB
57
The SuperKEKB accelerator recorded a peak luminosity more than twice that of the KEKB accelerator, but there are various challenges in updating the luminosity beyond that. One of the challenges is to eliminate sudden beam loss (SBL), in which a significant part of the circulating beam is lost in a few short turns. SBLs of the positron ring were investigated and found that the SBLs are characterized by vacuum pressure bursts at specific locations in the ring and an increase in beam size. From these measurements, it can be inferred that some phenomenon occurred at the location where the pressure burst was occurring, causing the beam size to increase and the beam to be lost in the narrow aperture of the ring. We performed knocker tests to artificially cause SBL and looked for possible sources of SBL. Based on several assumptions, we performed several works, including swapping the chamber up and down, cleaning the inside of the chamber, and knocking the chamber before operation. Of these works, the cleaning inside the chamber was found to be likely to be effective. This paper summarizes the measurement of SBL when it occurred and the countermeasures that contributed to its reduction.
Paper: MOCD3
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-MOCD3
About: Received: 28 May 2025 — Revised: 04 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 05 Nov 2025
MOCN2
Recent developments in the accelerator equipment automation field
61
CERN has embarked on a new programme of Particle Accelerator Efficiency improvements that is inspired by lessons learned from the last years of operation and by the latest technology advancements. The field of equipment automation is being addressed through a mix of concrete developments and pilot projects. This paper presents the work on preparing a new paradigm of accelerator equipment automation and reporting, anomaly detection and advanced analysis for predictive maintenance. An example of such automation is presented using the case of the SPS injection kicker (MKP) and the automatic classification of vacuum spike events to provide additional context to experts and stand-by personnel during interventions on the installation. This contribution also outlines how Kicker magnet faults caused by high voltage electrical discharge events can be distinguished from standard vacuum spike events, thus allowing a rapid automatic recovery without expert interventions.
Paper: MOCN2
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-MOCN2
About: Received: 28 May 2025 — Revised: 01 Jun 2025 — Accepted: 03 Jun 2025 — Issue date: 05 Nov 2025
MOCN3
Searches for RF breakdown precursors using Cherenkov light in optical fibers
65
RF breakdown studies are crucial for machines relying on high-gradient, normal-conducting RF accelerating cavities. Searches for breakdown precursors in high-gradient test-stand data have been conducted* and highlight the need for a new diagnostic with improved temporal response**. Emission of Cherenkov light in optical fibers has been identified as one such diagnostic***, which occurs when charge showers due to breakdown are incident on the fiber. Optical fibers have been used previously as distributed Beam Loss Monitors. At the X-Band Laboratory for Accelerators and Beams (X-LAB), we position optical fibers adjacent to X-band cavities being conditioned for the proposed Compact Linear Collider (CLIC). We assess sensitivity of fibers to charge emitted by field emission and breakdown events. Since breakdown precursors may occur at sub-microsecond timescales**, we survey photon detectors best suited to examining fiber response and identifying precursors. We compare fiber signals to dark current captured by upstream and downstream Faraday Cups. In search of precursory phenomena, pulse-by-pulse evolution of fiber signals is examined for field-emission activity prior to breakdown.
Paper: MOCN3
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-MOCN3
About: Received: 28 May 2025 — Revised: 02 Jun 2025 — Accepted: 03 Jun 2025 — Issue date: 05 Nov 2025
MOPB004
The data acquisition system on vibration evaluation and predictive maintenance for cooling water pumps system in TPS
75
The purpose of this paper is evaluating vibration status for cooling water pump system in TPS. The utility systems operate continuously since TPS commission in 2014. The predictive maintenance based on vibration level and spectrum became more important, especially for those unstoppable operate water pump systems. The vibration monitoring system started to construct in 2017 and upgraded in 2023. After vibration test over several months and years, some components of the cooling water pumps found abrasion and mismatched. The recorded data showed vibration level increase irregularly over ISO 10816 standard. The spectrum showed the detail status in the pump system. The cooling water pump systems repaired and maintained base on vibration evaluation after vibration evaluation. The utility systems could prevent malfunction at least over one month through regular vibration inspection and daily data acquisition. The data acquisition system for pump systems on vibration evaluation provided the predictive maintenance enough time to solve the problem and avoid system suddenly shutdown.
Paper: MOPB004
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-MOPB004
About: Received: 27 May 2025 — Revised: 02 Jun 2025 — Accepted: 03 Jun 2025 — Issue date: 05 Nov 2025
MOPB025
Plasma based optics for electron beam fast micro-bunching
118
The utilization of plasma devices in beam transport is slowly being accepted as a worthy alternative thanks to its potential in maintaining or even reducing particle beams emittance but also for its compactness which supplements the recent advances in compact laser plasma acceleration systems. However, their use can go beyond the substitution of magnets. In this work, the utilization of a low density plasma device to micro-bunch electron beams through a "cascade focusing" caused by the beam generated wake inside the plasma. In addition, specialized particle in cell tools to study such phenomena over long distance (>cm) taking advantage of relativistic reference frames is swiftly presented. Such devices present a great potential for shortening future FEL facilities and increasing the efficiency of current.
Paper: MOPB025
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-MOPB025
About: Received: 29 May 2025 — Revised: 30 May 2025 — Accepted: 01 Jun 2025 — Issue date: 05 Nov 2025
MOPB040
Leveraging the capabilities of LCLS-II: linking adaptable photoinjector laser shaping to x-ray diagnostics through start-to-end simulation
150
SLAC’s LCLS-II is advancing towards MHz repetition rate attosecond X-ray pulses, creating opportunities to optimize X-ray generation through machine-driven controls and diagnostics via start-to-end simulation. Advanced laser shaping and upconversion techniques at the photoinjector, such as spatial light modulator-based pre-amplifier pulse shaping linked to nonlinear methods such as dispersion-controlled nonlinear synthesis or four-wave mixing, enable precise electron bunch control at the source. Downstream, diagnostics like the Multi-Resolution COokiebox (MRCO)—a 16-channel time-of-flight spectrometer—characterize X-ray pulse profiles, providing real-time feedback on attosecond X-ray pulses or attosecond X-ray substructure. We present developments towards a framework linking programmable photoinjector laser shaping to X-ray diagnostics, enabling data-driven optimization of the X-ray source. This approach combines machine learning, high-throughput feedback, and advanced control to align LCLS-II capabilities with experimental goals, laying the foundation for optimization of attosecond-scale precision in X-ray experiments.
Paper: MOPB040
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-MOPB040
About: Received: 30 May 2025 — Revised: 02 Jun 2025 — Accepted: 03 Jun 2025 — Issue date: 05 Nov 2025
MOPB053
Preliminary beta beating correction at the Canadian Light Source
169
The Canadian Light Source does not currently correct beta beating driven by its insertions devices. However, it has been known for some time that insertion device correlated vertical beam size changes can cause large reduction in flux at the VESPERS beamline. In this work we discuss our preliminary explorations to control the vertical beam size and correct beta beating.
Paper: MOPB053
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-MOPB053
About: Received: 27 May 2025 — Revised: 03 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 05 Nov 2025
MOPB054
Evaluation of coating thickness and thermal deposited power for nonlinear in-vacuum kicker
173
This paper presents a comprehensive evaluation of the relationship between titanium coating thickness and thermal deposited power in the ceramic chambers of the Nonlinear In-vacuum Kicker (NIK) system, a critical component in synchrotron light sources. The study focuses on optimizing the coating thickness to minimize magnetic field attenuation and thermal load, thereby enhancing the performance of the NIK system. Through simulation analysis, we demonstrate that a titanium coating thickness of 5 μm provides an optimal balance between magnetic field attenuation and thermal load management. Additionally, the uniformity of the coating layer is found to significantly impact the system's stability and efficiency. The findings offer valuable insights for the design and operation of NIK systems in synchrotron facilities, particularly for the Taiwan Photon Source (TPS).
Paper: MOPB054
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-MOPB054
About: Received: 07 May 2025 — Revised: 08 Oct 2025 — Accepted: 08 Oct 2025 — Issue date: 05 Nov 2025
MOPB065
Application of fast algorithms to calculate dynamic and momentum aperture to the design of ALBA II
197
In synchrotron light sources, the non-linear magnetic fields and Touschek scattering limit the stability of electron motion, determining the dynamic aperture (DA) and the momentum acceptance (MA). Optimizing both the DA and the MA is crucial to maximize injection efficiency and the beam's lifetime, but it is numerically expensive. We implement recently developed algorithms that speed-up their calculation in CPUs: Flood Fill and Fast Touschek Tracking (FTT). Applying these to the analysis of the ALBA II lattice and comparing them to the existing methods, we obtain rigorous and faster results using Flood Fill, and ones with a slight loss of accuracy for FTT.
Paper: MOPB065
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-MOPB065
About: Received: 31 Mar 2025 — Revised: 30 May 2025 — Accepted: 01 Jun 2025 — Issue date: 05 Nov 2025
MOPB071
Simulation study on fast beam-based alignment for commissioning of light sources
204
Beam based alignment (BBA) plays an important role in the commissioning of the light sources. To speed up the BBA, a BBA method using AC excitation, called fast BBA (FBBA), has been proposed and is tested in several existing light sources. In the FBBA, the beam orbit is sinusoidally modulated at around 10Hz by AC correctors, and the change in the beam response when a target quadrupole magnet strength is changed is measured using fast beam position monitors (BPM) at about 10kHz. To apply FBBA to light source commissioning, a simulation study of FBBA using random variables as response functions was performed to calculate the optimal corrector strength and variation of the strength of a quadrupole as a function of the BPM noise. We also improved the FBBA and found that a new FBBA scheme using two AC correctors of different frequencies separated by 1/2π betatron phase for one plane (horizontal or vertical) can suppress the BPM offset error by up to 10.
Paper: MOPB071
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-MOPB071
About: Received: 28 May 2025 — Revised: 08 Oct 2025 — Accepted: 08 Oct 2025 — Issue date: 05 Nov 2025
MOPB075
SOLEIL synchrotron light source lastest news
216
The synchrotron SOLEIL is France's 2.75 GeV third-generation synchrotron light source and serves as a cutting-edge research laboratory dedicated to advanced experimental techniques for matter analysis at the atomic scale. It also functions as a service platform accessible to both scientific and industrial communities. This abstract highlights the performance of the accelerators, which deliver exceptionally stable photon beams to 29 beamlines. Key figures of merit from the past year are reported, along with a review of several incidents and the lessons learned to prevent recurrence. Additionally, major research and development efforts addressing component obsolescence are outlined. The status of the LINAC upgrade is also discussed, alongside plans to use SOLEIL's current accelerator as a test bench to validate and precommission critical equipment for the forthcoming SOLEIL upgrade.
Paper: MOPB075
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-MOPB075
About: Received: 02 Jun 2025 — Revised: 05 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 05 Nov 2025
MOPB089
Status of Sirius operation with users
228
SIRIUS is a state-of-the-art synchrotron light source facility, featuring a 3 GeV electron storage ring with a 518 m circumference and 250 pm·rad emittance. Built and operated by the Brazilian Synchrotron Light Laboratory (LNLS) in Campinas, Brazil, SIRIUS has undergone significant upgrades over the past year. These include the installation of a cryogenic plant, superconducting RF cavities, in-vacuum undulators, and new orbit feedforward systems, among others. This report summarizes these developments, highlights improvements in beam stability, and provides an overview of the facility’s operational status over the past year.
Paper: MOPB089
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-MOPB089
About: Received: 28 May 2025 — Revised: 04 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 05 Nov 2025
MOPB101
Bayesian optimization for the local bump injection in the HLS-II storage ring
242
Currently, a conventional local bump injection system with four pulsed dipole kicker magnets is adopted in the Hefei Light Source II (HLS-II) storage ring to achieve topoff operation. Due to the multipole magnets located between the kickers in the injection section, the local bump injection presents technical challenges in forming a perfect closed bump, which causes oscillation to the stored beam. In order to reduce the injection disturbance on the stored beam, the Bayesian Optimization (BO) method is employed to determine the kick angles of the four bump kickers.
Paper: MOPB101
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-MOPB101
About: Received: 09 Apr 2025 — Revised: 31 May 2025 — Accepted: 01 Jun 2025 — Issue date: 05 Nov 2025
MOPM007
FCC-ee energy calibration and polarization - Status and outlook
274
The Future electron-positron Circular Collider, FCC-ee, aims at high-precision particle physics experiments with beam energies from 45.6 to 182.5 GeV, corresponding to the Z-pole up to above the top-pair-threshold. These goals demand, among others, a precise knowledge of the center-of-mass energy and, hence, the beam energies. By depolarizing previously polarized pilot bunches and recording the change of polarization with a 3D polarimeter, it is aimed to determine the spin tune and thereby achieve a systematic uncertainty on the beam energy in the order of tens of keV. The latest progress of the work conducted by the FCC-ee energy calibration and polarization working group is reported here.
Paper: MOPM007
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-MOPM007
About: Received: 26 May 2025 — Revised: 05 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 05 Nov 2025
MOPM012
Parameter and luminosity scenarios for FCC-hh
294
In preparation for the 2026 Update of the European Strategy for Particle Physics, various options are being proposed for a future circular hadron collider, FCC-hh. Here, we discuss a few operational scenarios spanning c.m. energies from about 70-120 TeV, which correspond to the arc dipole field strengths ranging from 12 to 20 T. We present the respective integrated luminosity forecasts, considering a proton beam current similar to the one of the existing LHC (0.5 A) or the upcoming HL-LHC (1.1 A), and limiting the total synchrotron radiation power to at most 5 MW. Additional constraints are imposed on the beam-beam tune shift and the maximum event pile-up.on the maximum event pile up.
Paper: MOPM012
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-MOPM012
About: Received: 28 May 2025 — Revised: 31 May 2025 — Accepted: 02 Jun 2025 — Issue date: 05 Nov 2025
MOPM018
Energy sensitivity of the High Luminosity LHC optics at the end of the Beta* squeeze
318
During 2022 and 2023 LHC optics commissioning, it was observed that at low-beta* small changes in the beam-energy could generate substantial perturbations of the linear beam optics, requiring re-commissioning of local corrections in the experimental insertions. This issue may become even more significant at the very low beta* anticipated for operation in the High Luminosity LHC (HL-LHC). Furthermore, energy drifts, for example due to the terrestrial tides, have generally been ignored during LHC optics commissioning, with no regular corrections applied during the duration of a specific measurement campaign. This paper examines the anticipated sensitivity of HL-LHC optics corrections to energy errors at end of the beta* squeeze.
Paper: MOPM018
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-MOPM018
About: Received: 27 May 2025 — Revised: 30 May 2025 — Accepted: 02 Jun 2025 — Issue date: 05 Nov 2025
MOPM022
Criticality of powering failure of the main bend circuits in the FCC-ee at the Z-pole energy
334
The electron-positron Future Circular Collider (FCCee) will have a first phase of operation at the Z-pole energy of 45.6 GeV. To reach the target luminosity, a total of 11200 bunches with $2.14 \times 10^{11}$ charges will be used, accounting for a stored energy of 17.5 MJ per beam. Given the small beam emittances, the beam energy density in turn reaches extremely high values. The potential to induce severe damage to the accelerator components must be carefully evaluated for different failure scenarii. The effects of a powering failure of one of the main dipole circuits are described and discussed. The time-dependent effects are simulated with the XSuite tracking code. The results, expressed in term of orbit shifts, optics changes and particle losses, show that this failure is highly critical. The fastest scenario in which the beam experiences a horizontal orbit excursion of 11$\sigma$ in three turns is analysed in detail. Interlocking and mitigation strategies have been evaluated and are discussed.
Paper: MOPM022
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-MOPM022
About: Received: 28 May 2025 — Revised: 05 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 05 Nov 2025
MOPM024
Operational experience with automated beam loss analysis in the LHC
342
Every high-energy beam dump event at the Large Hadron Collider (LHC) is analysed to assess the performance of the machine protection system and to identify anomalous behaviour. Analysing the loss pattern of nearly 4000 beam loss monitors, which depends on beam parameters and machine settings, can be time-consuming and requires expert knowledge. Therefore, an automated beam loss analysis tool was developed and deployed in operation in November 2023. It uses empirically derived beam loss thresholds that scale with relevant beam parameters to evaluate beam dumps for post-mortem analysis. The paper describes how the beam loss thresholds were derived and optimised and reviews their performance in proton and Pb-ion operation.
Paper: MOPM024
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-MOPM024
About: Received: 28 May 2025 — Revised: 31 May 2025 — Accepted: 02 Jun 2025 — Issue date: 05 Nov 2025
MOPM028
Interplay between sextupole settings and single particle instabilities during the FCC-ee commissioning
358
The Future Circular Collider of electrons and positrons (FCC-ee) is designed to achieve high luminosity at center-of-mass energies ranging from the Z boson peak to the top quark threshold. During the commissioning phase, specialized optics are essential to accommodate the dynamic needs of machine tuning and beam stabilization. This paper investigates the role of sextupoles in the various FCC-ee commissioning optics, focusing on their influence on nonlinear beam dynamics. Using advanced simulation tools, we analyze how sextupole configurations impact key performance indicators, including the dynamic aperture, emittance evolution and lifetime. Strategies for optimizing sextupole strengths are explored. The findings provide critical insights for the design and optimization of the commissioning optics, ensuring efficient and reliable ramp-up to nominal operation. These results are instrumental in refining the FCC-ee commissioning strategy, supporting its broader objectives for particle physics research.
Paper: MOPM028
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-MOPM028
About: Received: 27 May 2025 — Revised: 03 Jun 2025 — Accepted: 04 Jun 2025 — Issue date: 05 Nov 2025
MOPM030
Impact of collective effects on beam stability in the FCC-ee main rings and the high-energy booster
366
The electron positron Future Circular Collider (FCC-ee) is considered the primary contender for the next major particle accelerator within the European Strategy for particle physics, aiming to achieve unprecedented luminosities to enable precise measurements of Z, W, and H bosons along with the top quark. Despite its potential, the FCC-ee project faces significant operational and design challenges, especially in managing collective effects such as space charge, wake fields, coherent synchrotron radiation, intra-beam scattering, and beam-beam interactions. The FCC-IS Feasibility Study brings together experts to address these challenges under one umbrella. This paper presents an updated status of the collective effects studies for FCC-ee main ring and high-energy booster, examining their implications and exploring potential mitigation strategies to prevent resulting instabilities.
Paper: MOPM030
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-MOPM030
About: Received: 29 May 2025 — Revised: 02 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 05 Nov 2025
MOPM032
Simulations of losses from fast instabilities in the FCC-ee
374
The electron-positron Future Circular Collider (FCC-ee) is a proposed high-energy lepton collider that aims to reach unprecedented luminosity and precision in the measurement of fundamental particles. To fully profit of such performance, it is crucial to keep detector backgrounds under control and operate the machine safely. Due to the high stored beam energy and to a number of complex operational features required at FCC-ee (e.g. the top-up injection scheme), controlling the backgrounds to the physics experiments becomes even more challenging. Recent studies on collective effects have shown that high impedance in the FCC-ee can lead to fast rise-time instabilities, where the beam amplitude grows exponentially, leading to beam loss within a few turns. Although a feedback system is being developed to mitigate this instability, failure scenarios of this feedback system need to be explored. This paper presents the study of the effects of this instability, in order to understand the possible implications for the machine and the experiments.
Paper: MOPM032
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-MOPM032
About: Received: 21 May 2025 — Revised: 30 May 2025 — Accepted: 01 Jun 2025 — Issue date: 05 Nov 2025
MOPM052
Bayesian methods and differentiable models for optics studies at the ISOLDE facility
449
The Isotope mass Separator On-Line facility (ISOLDE) delivers a wide range of low-energy radioactive ion beams to its experimental users. To meet varying demands, the facility uses different target materials, ionization methods, and cooling/bunching techniques, with beam configurations potentially changing weekly. To model particle transport through the transfer lines, it is essential to reconstruct the beam's initial transverse phase space for each setup, achieved via quadrupole scan measurements. This work explores the application of Bayesian techniques and differentiable models to reduce the time required to perform the beam setup.
Paper: MOPM052
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-MOPM052
About: Received: 26 May 2025 — Revised: 02 Jun 2025 — Accepted: 03 Jun 2025 — Issue date: 05 Nov 2025
MOPM064
Operational experience and design improvement studies of the LHC MKI cool
466
In view of the unprecedented beam intensities expected in the High-Luminosity era of the Large Hadron Collider (HL-LHC), an upgrade of the LHC injection kickers (MKIs) is currently underway. This upgrade aims to mitigate excessive beam-induced heating of the MKIs and to limit resulting vacuum activity. The first MKI Cool was installed in the LHC during the Year End Technical Stop (YETS) in 2022-2023, and the upgrade of the entire system of 8 injection kickers is expected to be completed during Long Shutdown 3 (LS3). This paper discusses the operational performance of the new MKI Cool magnets and compares it to the magnets of the post-LS1 design. Additionally, it focuses on investigations aimed at understanding the observed results, with the goal of further enhancing the performance of the MKI Cool design.
Paper: MOPM064
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-MOPM064
About: Received: 28 May 2025 — Revised: 01 Jun 2025 — Accepted: 03 Jun 2025 — Issue date: 05 Nov 2025
MOPM065
Feasibility of kicker systems for FCC-ee and injectors
470
CERN’s Future Circular Collider (FCC) comprises a ~91 km circumference lepton collider and its injector complex. This contribution summarises the feasibility studies performed for the various kicker systems needed to transfer the beam between the different machines. The individual system requirements are reviewed, recent changes are highlighted, and the chosen conceptual design is outlined. Particular effort has been made to harmonise the hardware parameters across the machines to minimise the number of different beam line element types. The feasibility of the design parameters and technology options is discussed for both beam line elements and pulse generators. Early system integration aspects and implications on subsystems such as pulse transmission cables are also discussed. Consequences of the more restrictive requirements on the abort gap length in the collider are analysed. This contribution concludes with recommendations for detailed studies and prototyping required to ensure a viable parameter space for the upcoming detailed technical design phase.
Paper: MOPM065
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-MOPM065
About: Received: 27 May 2025 — Revised: 31 May 2025 — Accepted: 01 Jun 2025 — Issue date: 05 Nov 2025
MOPM066
Performance improvement studies for the CERN SPS MKDH system
474
The CERN-SPS beam dump system (SBDS) is equipped with a dilution kicker system, the so-called MKDH. During the 2022 and 2023 beam commissioning, the vacuum rise in the MKDH became a concern for reaching the anticipated higher beam intensities. Dedicated conditioning of the SPS kickers enabled successful attainment of High-Luminosity (HL) beam intensities during 2024 operation. However, the conditioning time required after replacing an MKDH magnet remains a significant concern, leading to a study aimed at optimizing its high intensity performance. This paper presents a feasibility assessment, a detailed characterization of the operational kickers and the spare units, and proposed modifications designed to optimize the MKDH kicker magnet performance. The modifications focus on minimizing interactions and coupling between the kicker and the beam, with the ultimate goal of improving the operational efficiency with high intensity beams.
Paper: MOPM066
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-MOPM066
About: Received: 28 May 2025 — Revised: 01 Jun 2025 — Accepted: 03 Jun 2025 — Issue date: 05 Nov 2025
MOPM071
Dual-purpose structure for light and heavy particles
490
A dual-purpose structure has been developed for the NICA collider accelerating heavy multiply charged ions and light polarized nuclei of protons and deuterons. For heavy multiply charged ions, it is necessary to solve the problem of intrabeam scattering, which requires minimal modulation of the envelope and dispersion function. For light particles, the problem of crossing transition energy arises. In the proposed structure, both problems are solved due to a specially developed structure of magnetic arcs. This magneto-optical structure can be used to accelerate both heavy ions and light polarized protons and deuterons without loss of beam quality.
Paper: MOPM071
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-MOPM071
About: Received: 28 May 2025 — Revised: 30 May 2025 — Accepted: 31 May 2025 — Issue date: 05 Nov 2025
MOPM079
Automated conditioning utilizing machine-learning: first experimental results
506
The conditioning of room temperature cavities is a long process. Additionally, since the cavity or auxiliary equipment can be damaged, constant supervision or extensive safety precautions are required. To reduce the workload for everyone involved and to increase the efficiency of the conditioning process, it was decided to develop a machine learning algorithm with the goal of fully automated conditioning in mind. The initial model was trained on available data of the low energy-domain (up to 500 W). Since it was possible to expand the data to higher power levels during conditionings in 2024, the algorithm is now trained for power levels up to 30 kW. In this paper, the challenges of training with different power scales, as well as the first experimental results shall be discussed.
Paper: MOPM079
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-MOPM079
About: Received: 28 May 2025 — Revised: 29 May 2025 — Accepted: 30 May 2025 — Issue date: 05 Nov 2025
MOPS004
Longitudinal hollow electron beam
588
The intra-beam scattering in high charge state intense heavy ion beams is a problem worth considering. With the help of controlling the longitudinal distribution of the ion beam, it may be possible to alleviate the ion beam loss and to improve the ion beam lifetime caused by intra-beam scattering. Unlike the traditional cooling process of direct current electron beams or longitudinal uniform distribution electron beams, a longitudinal hollow electron beam is used to cool heavy ion beams. Ions at the edge of the ion beam will receive stronger cooling, while ions at the center of the ion beam will receive weaker cooling, avoiding overcooling at the center of the ion beam. This paper discusses the generation, measurement, and related issues of longitudinal hollow electron beams. Corresponding solutions and suggestions have been proposed for the problems and challenges that may be encountered in the research. The cooling process of longitudinal hollow electron beams will be simulated and experimentally studied in the further, with the hope of obtaining beneficial effects.
Paper: MOPS004
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-MOPS004
About: Received: 09 May 2025 — Revised: 30 May 2025 — Accepted: 08 Oct 2025 — Issue date: 05 Nov 2025
MOPS007
Characterisation and mitigation of RF knockout
600
Beam stacking is a key advantage of Fixed Field alternating gradient Accelerators (FFAs) for high-intensity applications. During stacking, one beam is stored as a coasting beam at the extraction energy while another, incoming beam is accelerated. However, the beam loss mechanism termed RF knockout can occur during stacking and undermine gains in extracted beam current. The accelerating RF program of the incoming beam can cause cumulative displacements in the stored coasting beam and result in significant beam loss. To ensure that beam stacking is a viable technique to extract highest intensities from an FFA, methods to avoid the loss from RF knockout must be established. This study presents results from a series of experiments at the ISIS proton accelerator to characterise and, crucially, to mitigate RF knockout and ensure successful beam stacking with no loss.
Paper: MOPS007
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-MOPS007
About: Received: 27 May 2025 — Revised: 03 Jun 2025 — Accepted: 04 Jun 2025 — Issue date: 05 Nov 2025
MOPS008
Introduction of key performance indicators for the GSI accelerator facility
604
The GSI Facility consists of several accelerators, offer-ing the distinctive capability to provide different ion beams with varying characteristics to a range of experi-ments simultaneously. In order to facilitate the monitor-ing of machine performance across diverse beam produc-tion chains and experiments, a Key Performance Indica-tor (KPI) metrics has been introduced. The CRYR-ING@ESR team has completed an initial KPI assessment of the ion storage ring and developed procedure to ana-lyse beam diagnostic data offline. Initial analysis has identified lacking information and features in the FAIR Archiving System (FAS) and data structures to support automated tracking of machine performance. This paper will present detailed definitions of KPIs to enable quanti-tative, beam-based accelerator performance measure-ment, an assessment of their implementation and an outline of future developments.
Paper: MOPS008
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-MOPS008
About: Received: 27 May 2025 — Revised: 05 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 05 Nov 2025
MOPS031
Preliminary results of crystal channelling optimisation in the LHC using reinforcement learning
671
The Large Hadron Collider (LHC) can operate with high intensity proton and heavy ion beams, both of which require a collimation system to ensure an efficient operation and to protect against damage to sensitive equipment along the ring. The crystal collimation scheme using bent silicon crystals as primary collimators was therefore introduced to improve the collimation efficiency for heavy ion-beams. The first operational deployment of crystal-assisted collimation was achieved in the 2023 Pb run. This demonstrated the required performance gain to safely handle high intensity ion beams, but undesired crystal rotation led to the loss of optimal performance during physics fills. The cause of this is thought to be mechanical deformation of the goniometer due to heating related to beam impedance effects. Hence, a conventional numerical optimiser was deployed to monitor and compensate for crystal angular errors based on a set of beam-loss monitors. The problem at hand, allows for the use of machine learning techniques to ensure continuous optimal channelling, minimising convergence time and eventually the optimization of crystals in multiple planes in parallel.
Paper: MOPS031
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-MOPS031
About: Received: 24 May 2025 — Revised: 03 Jun 2025 — Accepted: 03 Jun 2025 — Issue date: 05 Nov 2025
MOPS039
Direct MOGA optimization of touschek lifetime and dynamic aperture using fast touschek tracking
694
A large momentum acceptance (MA) in 4th generation storage ring light sources is paramount to obtaining a long Touschek lifetime. However, the calculation of MA typically requires computationally expensive tracking simulations thereby complicating, or even disabling, the direct optimization of Touschek lifetime using numerical optimization algorithms. Our recent development of Fast Touschek Tracking allows obtaining the MA two orders of magnitude faster than standard MA tracking, thereby enabling direct optimization of Touschek lifetime. We present an example of a Multi-Objective Genetic Algorithm (MOGA) optimization of both on-energy dynamic aperture and direct Touschek lifetime using Fast Touschek Tracking for a 4th generation storage ring.
Paper: MOPS039
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-MOPS039
About: Received: 28 May 2025 — Revised: 03 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 05 Nov 2025
MOPS047
Development of new ion beams at the CERN ion injector complex for future physics programmes
718
In an effort driven by the requests from different physics experiments at CERN, the CERN ion injector complex is looking to expand its capabilities by providing lighter-than-lead ion beams. Argon and xenon were delivered for NA61/SHINE physics in 2015 and 2017, with xenon also reaching the LHC in 2017. Oxygen is foreseen to be collided in the LHC in 2025, with magnesium, boron and krypton beams also being prepared. Before new ion species can be considered operational for experiments, the feasibility of producing and accelerating these beams throughout the accelerator complex has to be assessed. This contribution presents an overview of the performance of the ion complex with recently tested magnesium ion beams, the latest results of the ongoing oxygen beam commissioning, and future plans concerning ion species that still need to be developed.
Paper: MOPS047
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-MOPS047
About: Received: 02 Apr 2025 — Revised: 03 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 05 Nov 2025
MOPS052
Overview of ESRF-EBS's four-year operation and strategy for further upgrade
733
The user operation of the Extremely Brilliant Source (EBS) since August 2020 has opened a new era of high energy fourth generation synchrotron radiation light sources. During the following four years of operation, the EBS accelerator has sustained user operation with high availability, reliability, and stability, and has continued to improve beam performance by reducing injection perturbations, increasing bunch/beam currents for different beam delivery modes, and consolidating the storage ring operation with a hot-swap power supply system, newly designed kicker ceramic chambers, etc. Sustainability has always been key to EBS operation and future upgrades. During user operation, measures on the RF system of the storage ring and HQPS operation have been implemented to save power consumption; in the near future, solid-state amplifiers and 4th harmonic RF system projects will ensure the sustainability of machine operation further. In addition, as a strategy for future upgrades of the EBS accelerator complex, injector upgrades are being considered, including the injection with a new linac, which can be further upgraded to inject full-energy beam into the storage ring.
Paper: MOPS052
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-MOPS052
About: Received: 29 May 2025 — Revised: 13 Oct 2025 — Accepted: 13 Oct 2025 — Issue date: 05 Nov 2025
MOPS055
Magnet assembly of IVUE32 in-vacuum-APPLE II at BESSY II
741
At HZB / BESSY II the first in-vacuum APPLE II undu-lator is under construction. The design includes three magnet arrays for each of the four magnet rows for an efficient force compensation. The support and drive sys-tem has been delivered. Currently the magnets for the 10-period prototype are fabricated by Vacuumschmelze. Within the project IVUE32 a new soldering technique based on reactive foils has been developed in collabora-tion with Vacuumschmelze. The magnet structure of the IVUE32 undulator will employ the soldering technique aiming for enhanced assembly simplicity. Two new ex-perimental setups for the characterization of soldered subassemblies have been built for obtaining stress-strain curves and for lifetime (fatigue) tests. These instruments will be presented and measurements will be discussed.
Paper: MOPS055
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-MOPS055
About: Received: 19 May 2025 — Revised: 04 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 05 Nov 2025
MOPS069
The Elettra 2.0 project status
768
After 31 years of serving the user community with excellent results, on July 2nd 2025 the removal of the Italian third generation synchrotron light source Elettra (www.elettra.eu) will start to be replaced by Elettra 2.0 a fourth-generation one. The project is in full development and, being a diffraction limited light source, Elettra 2.0 will provide ultra-high brilliance and coherence to the experiments while at the same time the machine is designed to provide very short pulses for time resolved experiments. The project status and its possibilities will be presented and discussed
Paper: MOPS069
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-MOPS069
About: Received: 24 Apr 2025 — Revised: 13 Oct 2025 — Accepted: 13 Oct 2025 — Issue date: 05 Nov 2025
MOPS092
Progress on beam dynamics studies for the ISRS isochronous ring spectrometer
793
A new lattice configuration is being developed for a compact,isochronous ring for the ISRS project, as an innovative spectrometer at HiE-ISOLDE. The design incorporates ten combined-function, canted cosine-theta (CCT) superconducting magnets, enabling the ring to fit within a constrained 5x5 meter hall space. This design presents significant challenges, particularly in accommodating the injection and extraction of a high beam rigidity beam, as the CCT magnets mechanical dimensions severely limit the space available for these subsystems. Using Bmad code simulations, the performance of beam injection and extraction, based on a high-field, superconducting septum and a fast magnetic kicker, is evaluated, along with the time-of-flight separation of various isotope ion products from selected nuclear reactions of interest.
Paper: MOPS092
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-MOPS092
About: Received: 09 May 2025 — Revised: 02 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 05 Nov 2025
TUXD1
Personnel and machine protection for high power accelerator commissioning, operations, and power ramp up
844
Safety is one of the main concerns in accelerator society. The key FRIB strategies and experience can be shared, leading to the successful FRIB operations with no safety-related incidents and meeting stringent standard in a university area. Personnel protection and machine protection are key to high power frontier facilities like FRIB. For a facility built in the middle of university campus with heavy ion beam power being ramped up order of magnitude higher than the current record, stringent engineered and administrative controls and state-of-the-art technologies are needed to safeguard commissioning, operations, and upgrades.
Paper: TUXD1
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-TUXD1
About: Received: 28 May 2025 — Revised: 03 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 05 Nov 2025
TUAN1
A Study on Eddy Current Distribution in the Coating Layer of a Nonlinear Kicker Chamber
866
This study presents 2D approximated expressions for eddy currents in the Ti-coated layer of a nonlinear kicker and compares them with numerical simulations. Nonlinear kicker-based injection schemes have be-come popular in recent years and are used at several facilities. Eddy currents, which depend on both the applied magnetic field and the chamber’s geometry, can create unwanted field components. The proposed approximations offer a fast and practical way to esti-mate the effects of these eddy currents.
Paper: TUAN1
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-TUAN1
About: Received: 28 May 2025 — Revised: 04 Jun 2025 — Accepted: 04 Jun 2025 — Issue date: 05 Nov 2025
TUCN1
Communicating environmental sustainability guidelines for large accelerator facilities
923
In the coming decades, numerous designs for new accelerator-based facilities, or potential upgrades to current facilities, have been proposed to support the next generation of scientific advancement. While these facilities have significant scientific, economic, and societal benefits, they also require considerable resources to operate effectively. Amid the ongoing climate crisis, these facilities face the challenge of balancing the need for increased scientific output, size, and/or power with the global need to reduce resource consumption. This challenge presents a unique opportunity to integrate innovative environmental impact reduction techniques into their design. The presented living document offers high-level guidelines to enhance environmental sustainability across the planning, construction, operation, and decommissioning stages of large accelerator facilities. It consolidates various resources and highlights both existing and proposed practices to inspire more sustainable approaches.
Paper: TUCN1
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-TUCN1
About: Received: 28 May 2025 — Revised: 31 May 2025 — Accepted: 04 Jun 2025 — Issue date: 05 Nov 2025
TUCN2
Engineering magnetic carbon nanotubes via swift heavy ion irradiation for spintronics and quantum technologies: XAS and RAMAN study
925
Carbon nanotubes (CNTs), known for their versatility as 2D materials, are key to advancing quantum technologies such as qubit fabrication and magnetic data storage. In this study, multi-walled carbon nanotubes (MWCNTs) doped with magnetic impurities (Fe and Co) were exposed to swift heavy ion (SHI) irradiation to explore induced structural modifications. SHI beams transfer energy to the carbon matrix via electronic energy loss and thermal spikes, causing Fe and Co ions to agglomerate within interstitial regions and defect sites of the CNT matrix. Structural changes were analyzed using high-resolution X-ray diffraction (HRXRD), Raman spectroscopy, and near-edge X-ray absorption fine structure (NEXAFS). HRXRD revealed peak dissolution, reduced crystallinity, and increased lattice strain, while Raman spectra showed partial annealing of damaged CNTs with disorder parameter reduction (FeCNT: 0.65→0.57; CoCNT: 0.55→0.52). NEXAFS confirmed non-destructive processing. These findings link ion fluence with defect engineering, paving the way for magnetic CNTs in spintronics and data storage.
Paper: TUCN2
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-TUCN2
About: Received: 11 Jun 2025 — Revised: 12 Jun 2025 — Accepted: 14 Jun 2025 — Issue date: 05 Nov 2025
TUPB003
Beyond 1 MW operation of the J-PARC RCS
936
Beyond 1 MW operation of the J-PARC RCS The 3-GeV Rapid Cycling Synchrotron (RCS) of the Japan Proton Accelerator Research Complex (J-PARC) has already been achieved the designed 1 MW operation to the Material and Life Science Experimental Facility (MLF). However, to cope with the gradually getting faster operation cycle of the main ring synchrotron sharing more beam requires RCS to accelerate more than 1 MW beam per pulse for the MLF to ensure net 1 MW beam power at the MLF. Moreover, the beam sharing to the under designed 2nd MLF target facility has also to be considered. As a result, the next goal is to realize 1.5 MW beam power first and continue for 2 MW or even more. This will be done by injecting more particles in the RCS by increasing both peak current and pulse duration of the injection beam. Beam dynamics issues and possible scenarios to realize far beyond 1 MW in the RCS are presented.
Paper: TUPB003
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-TUPB003
About: Received: 29 May 2025 — Revised: 02 Jun 2025 — Accepted: 04 Jun 2025 — Issue date: 05 Nov 2025
TUPB006
Readiness of the HEARTS@CERN facility for space electronics high-energy heavy-ion testing
948
The HEARTS@CERN activity in the framework of the HEARTS (High-Energy Accelerators for Radiation Testing and Shielding) EU project is targeted at enhancing Europe’s high-energy (>100 MeV/n) heavy ion electronics irradiation capability through the development of an irradiation beam combining unique penetration and ionization characteristics. These types of tests are essential for exploiting commercial electronics in space. Throughout 2024, the HEARTS@CERN efforts have focused on achieving and demonstrating compliance with the space user radiation effects testing requirements. This includes being able to offer a wide range of energies (and Linear Energy Transfer values) and fluxes, with a high level of accuracy and a rapid change between parameters. Moreover, large homogeneous beams are necessary for enabling the test of multiple electronic components in parallel, and for performing board level testing. This work will present requirements for high-energy heavy ion testing along with the level of compliance achieved, as demonstrated during the November 2024 HEARTS@CERN user run, with a focus on the beam related parameters, but including also facility and procedural considerations.
Paper: TUPB006
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-TUPB006
About: Received: 27 May 2025 — Revised: 03 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 05 Nov 2025
TUPB019
Investigation and mitigation of magnetic field emissions in the SMH16 septum system's high-current cable connections
991
The SMH16 system at CERN is a pulsed septum magnet driven by a single period of a flattened sine wave current with a fundamental frequency of approximately 2.5 kHz and a peak current of 28 kA. The magnet connects to its pulse generator via ten high-voltage, high-power cables, each containing go, return, and ground conductors and coarse shielding. Due to the high currents, magnetic field emissions could interfere with nearby equipment and affect electromagnetic compatibility. This work investigates these magnetic field emissions and evaluates potential shielding measures. 2D field simulations of the cable connections to model the emissions and assess the effectiveness of additional shielding configurations have been conducted. To validate the simulations, time-dependent magnetic field measurements using a magnetic near-field probe, and a custom Hall probe were performed on a section of the cable connection in a full-scale test setup of the SMH16 system, both with and without extra shielding around the cable bundle. The results showed good agreement between simulations and measurements. Additional shielding can significantly reduce magnetic field emissions.
Paper: TUPB019
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-TUPB019
About: Received: 28 May 2025 — Revised: 30 May 2025 — Accepted: 01 Jun 2025 — Issue date: 05 Nov 2025
TUPB022
Reduction of beam loss at the fast extraction section in J-PARC MR
1002
At J-PARC MR, proton beams are supplied to the neutrino facility via fast extraction (FX). The beam power, which was 500 kW in 2021, reached 800 kW by June 2024, with further upgrades planned. This increase in power has led to a rise in beam loss in the FX section, necessitating countermeasures. Residual doses are high at positions where the FX beam orbit closely approaches the aperture, and the effectiveness of beam loss countermeasures is evaluated by changes in residual dose. By June 2024, residual doses were successfully reduced through adjustments to the beam optics. For further reduction of beam loss, in July 2024, the aperture was expanded at the most upstream position where the beam orbit is in close proximity to the aperture. This report discusses the achievements during subsequent FX operations and outlines plans for further improvements.
Paper: TUPB022
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-TUPB022
About: Received: 28 May 2025 — Revised: 03 Jun 2025 — Accepted: 04 Jun 2025 — Issue date: 05 Nov 2025
TUPB034
Status of the pulsed hydrogen gas stripper project at GSI
1044
The operation of the specifically upgraded pulsed gas stripper development setup for the user beamtime lasted until July 2024. It was very successful in terms of both providing stripped ions and gaining valuable experience in the long-term operation of the pulsed stripper. The long periods of high duty nitrogen operation revealed a severe service life issue of the fast injection valves, which was already anticipated in the risk assessment for the hydrogen operation. This emphasizes the need for the safety measures incorporated in the design of the pulsed stripper facility. During the user beamtime, several measurement campaigns were conducted. Extensive data on the stripping efficiencies for 12 projectile-target combinations could be obtained. In this contribution the obtained results and lessons learned are presentet as well as the necessary next steps to finaly bring the hydrogen stripping to routine operation.
Paper: TUPB034
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-TUPB034
About: Received: 27 May 2025 — Revised: 30 May 2025 — Accepted: 04 Jun 2025 — Issue date: 05 Nov 2025
TUPB047
CERN-MEDICIS: A unique facility for the production of radionuclides for medical research
1071
The MEDICIS facility is a unique facility located at CERN, dedicated to the production of non-conventional radionuclides for research and development in imaging, diagnostics and radiation therapy, and based on offline mass separation. It exploits a classified area for handling of highly radioactive open sources, a dedicated isotope separator beam line, a target irradiation station at the 1.4 GeV Proton Synchroton Booster (PSB) and receives activated targets from external institutes during CERN Long Shut-Downs. After collection, the batch is prepared to be dispatched to a research center. Since its commissioning in December 2017, the facility has provided novel radionuclides such as Ba-128, Tb-155, Sm-153, Tm-165 Ra-224/Pb-212 and Ra-225/Ac-225 with high specific activity, some for the first time, to research institutes part of the collaboration. CERN-MEDICIS has advanced significantly to reach mature processes to translate into clinical application for the most promising radionuclides.
Paper: TUPB047
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-TUPB047
About: Received: 17 May 2025 — Revised: 02 Jun 2025 — Accepted: 04 Jun 2025 — Issue date: 05 Nov 2025
TUPB059
Analysis of low-frequency disturbances (0.3 Hz) in TPS and TLS beam orbit feedback systems
1102
The stability of electron beams in storage rings is vital for precise synchrotron radiation experiments. However, external vibrations, such as earthquakes, ocean waves, and human activities, often disrupt beam stability. This study analyzed low-frequency(~0.3Hz) disturbances in the beam orbit systems of the Taiwan Photon Source (TPS) and Taiwan Light Source (TLS). Using Fast Fourier Transform (FFT) and Dynamic Time Warping (DTW), we identified a strong correlation between these disturbances and ocean wave frequencies, with a similarity score of 0.12. Our findings confirm ocean waves as a major disturbance source and emphasize the need for advanced orbit control and vibration compensation to enhance beam stability.
Paper: TUPB059
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-TUPB059
About: Received: 26 May 2025 — Revised: 01 Jun 2025 — Accepted: 04 Jun 2025 — Issue date: 05 Nov 2025
TUPB068
Density measurements and simulations on confined electron column in GL2000 Gabor-lens device
1120
GL2000 Gabor-lens (GL) is a 2m long device built mainly for focusing and space charge compensation of hadron beams in energy ranges up to GeV. The electron cloud is initially produced by cold-cathode method with gradually ionisation of residual gas and is confined in a cylindrical trap much longer compared to previous constructed lenses. Density measurements were carried out at the test-stand in Goethe University in 2024. Outgoing stream of residual gas ions was detected within cylindrical spectrometer mounted on axis outside of the lens. Due to the dependency of the kinetic energy on starting potential, the on-axis potential and therefore confined average charge density can be derived. Measured densities were evaluated in a range of $10^{14}$-$10^{15} m^{-3}$. A large scale multi-particles Monte-Carlo-PIC (particle-in-cell) simulations with electrons and ions were carried out to understand collective phenomena in non-neutral plasma and to use the latter for linear and non-linear beam manipulation. Measurements and simulation results will be presented.
Paper: TUPB068
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-TUPB068
About: Received: 28 May 2025 — Revised: 13 Oct 2025 — Accepted: 13 Oct 2025 — Issue date: 05 Nov 2025
TUPB072
Progress of beam power upgrade in J-PARC main ring
1124
In the J-PARC main ring (MR), a project to increase the beam power with higher repetition rates and higher beam intensities is now in progress, aiming to achieve 1.3 MW in the fast extraction (FX) mode and >100 kW in the slow extraction (SX) mode. Beam power has generally been increasing as planned with progress of hardware upgrades and beam dynamics tuning; beam powers of 800 kW (FX) and 80 kW (SX) have been achieved as of December 2024. This paper reports on the recent progress of the beam power upgrade in MR.
Paper: TUPB072
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-TUPB072
About: Received: 31 May 2025 — Revised: 02 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 05 Nov 2025
TUPB075
Bunch lengthening of the extraction beam using second harmonic in J-PARC RCS
1132
The 3GeV Rapid-Cycling Synchrotron (RCS) at J-PARC supplies the beam to the Main Ring (MR). Under the current operating conditions, there is the longitudinal beam mismatch between RCS and MR. To improve the RCS-MR longitudinal matching, a method for the bunch lengthening of RCS at the extraction is proposed. The method is based on introducing a second harmonic RF voltage at beam extraction and placing the beam at the unstable fixed point. The considerations of the bunch lengthening in the RCS are described in this presentation. The focus is on optimizing the second harmonic RF voltage pattern. Demonstrations of introducing a second harmonic RF voltage are also discussed.
Paper: TUPB075
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-TUPB075
About: Received: 07 Apr 2025 — Revised: 05 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 05 Nov 2025
TUPB099
Recent developments in delivering mixed helium and carbon ion beams at MedAustron
1147
Simultaneous irradiation with mixed helium and carbon ions is being proposed for online range verification in carbon radiotherapy. In 2024, a mixed $^4$He$^{2+}$ and $^{12}$C$^{6+}$ beam, generated by sequential injection of helium and carbon ions into the synchrotron, was extracted successfully for the first time at the MedAustron ion beam therapy and research center. This double injection scheme comes with challenges concerning the capture, acceleration, and slow extraction, as injection energy offsets and differences in horizontal phase distributions have to be considered in addition to the small offset in charge-to-mass ratio between $^4$He$^{2+}$ and $^{12}$C$^{6+}$. This proceeding reports on recent developments in the delivery of this mixed ion beam at MedAustron using a double injection scheme, which includes an additional deceleration ramp for helium ions between the injections of helium and carbon, as well as progress towards a measurement setup for the time-resolved quantification of the ion mixing ratio at delivery.
Paper: TUPB099
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-TUPB099
About: Received: 27 May 2025 — Revised: 31 May 2025 — Accepted: 04 Jun 2025 — Issue date: 05 Nov 2025
TUPM018
A study of improving stability and reliability in PAL-XFEL modulator system
1202
In the PAL-XFEL system, an X-ray free electron laser facility, 51 modulator power supplies in total have been operated with thyratron tubes as the high voltage pulse switch devices in order to drive an X-band linearize and 50 S-band klystrons for a beam energy of 10 GeV. PAL-XFEL requires beam energy stability of less than 0.02% and very tight control of the klystron RF phase jitter. The modulator output pulse amplitude stability is directly related to the RF phase jitter. There are several factors to satisfy stability and reliability for the PAL-XFEL modulator. The largest sources of pulse-to-pulse instability are a current charging power supply (CCPS) for PFN charging, thyratron switch parts, and a klystron focusing magnet power supply. This paper describes how to deal with the failures of these devices and the debugging results.
Paper: TUPM018
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-TUPM018
About: Received: 04 Apr 2025 — Revised: 13 Oct 2025 — Accepted: 13 Oct 2025 — Issue date: 05 Nov 2025
TUPM021
An update of progress on the design of the diffraction line for the relativistic ultrafast electron diffraction and imaging facility at Daresbury Laboratory
1208
The Relativistic Ultrafast Electron Diffraction and Imaging (RUEDI) facility is an approved project to provide ultrafast capability to UK researchers. The current design involves two separate beamlines for diffraction and imaging but with shared infrastructure including laser pump sources. This presentation describes recent progress in the design of the diffraction line. The diffraction line has a 2.4 cell S-band RF gun to produce 4 MeV electron bunches. Bunch compression to the sub-10 fs range is carried out with a triple bend achromat design that also suppresses arrival time jitter*. Interchangeable sample chambers are planned to allow wide ranging experiments from both solid samples at room and cryogenic temperatures and liquid and gas targets. Post sample optics are provided to image the diffraction pattern on to a high-resolution single electron sensitive detector. Temporal diagnostics including an RF TDC and THz deflector are included along with a spectrometer at the end of this line to measure beam energy.
Paper: TUPM021
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-TUPM021
About: Received: 23 May 2025 — Revised: 05 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 05 Nov 2025
TUPM046
Study on deposition method for improving quantum efficiency and lifetime of NEA-GaAs photocathode using cesium, antimony and oxygen
1256
Negative Electron Affinity (NEA) activated GaAs photocathodes are the only one capable of generating spin-polarized electron beam larger than 90%. However, the NEA layer currently made from mainstream cesium (Cs) and oxygen (O) is chemically unstable, the NEA-GaAs photocathode has a rapid quantum efficiency degradation over time or electron beam. As a result, it requires an operating vacuum pressure of below 10-9 Pa and has a short lifetime. Recently, a new NEA layer using heterojunctions with semiconductor thin films of alkali metals and antimony (Sb) or tellurium has been proposed. Recent works have shown that the deposition of the NEA layer was realized using cesium, antimony and oxygen. In this work, we attempted to introduce Sb at two different timing. One is introduction from the beginning, and the other one is introduction after Cs and oxygen deposition. We systematically investigate the deposition temperature and antimony thickness to find the optimal conditions for improving quantum efficiency and lifetime. We will report the latest results.
Paper: TUPM046
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-TUPM046
About: Received: 20 May 2025 — Revised: 03 Jun 2025 — Accepted: 03 Jun 2025 — Issue date: 05 Nov 2025
TUPM048
Development of electronic orbit stability monitoring and analysis system in the Taiwan Photon Source
1259
The Taiwan Photon Source (TPS) storage ring features 172 strategically deployed Beam Position Monitors (BPMs) forming a high-precision electron orbit monitor-ing network. This paper presents an automated monitoring system that periodically extracts BPM data from the data-base and calculates standard deviations to quantify beam stability through statistical methods. The system employs a hierarchical filtering algorithm to identify BPMs with the highest standard deviations and generates analytical visualizations while tracking temporal trajectories of sig-nificantly varying BPMs. During the resolution of BPM electrode anomalous jumps, we developed and integrated a Q-value-based anomaly diagnostic method that effective-ly differentiates between BPM electrode anomalies and actual orbit variations. The system incorporates the LINE Bot API for real-time notification capabilities, establish-ing a comprehensive data acquisition-analysis-alert work-flow. Through its multi-level monitoring architecture, the system has successfully identified and resolved several critical issues affecting beam stability, including electrode abnormalities in BPM183 and BPM126, significantly enhancing source stability and providing users with more reliable beam quality assurance.
Paper: TUPM048
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-TUPM048
About: Received: 21 May 2025 — Revised: 02 Jun 2025 — Accepted: 13 Oct 2025 — Issue date: 05 Nov 2025
TUPM054
Progress towards kick and cancel injection for Diamond-II
1270
With the aim of maintaining transparent and efficient injection during top-up, a kick-and-cancel injection scheme has been developed for Diamond-II. In this, stripline kickers are used with 3 ns pulses to deflect individual bunches, with the stored bunch receiving two kicks separated by 180 degrees phase advance to leave it on-axis and the injected bunch timed to arrive at the second kick. In this paper we present progress with the hardware design and recent prototyping results, alongside updates to the simulations.
Paper: TUPM054
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-TUPM054
About: Received: 19 May 2025 — Revised: 02 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 05 Nov 2025
TUPM057
Commissioning of the SLS 2.0 machine protection system
1278
The Swiss Light Source (SLS) at the Paul Scherrer Institute (PSI) was Switzerland’s first and only 3rd-generation light source. For the SLS 2.0* upgrade the old 2.4 GeV, 12-fold 3-bend achromat lattice with 5 nm horizontal emittance was decommissioned in September 2023 after 22 years of successful user operation. The new 2.7 GeV storage ring has a 12-fold 7-bend achromat lattice achieving 150 pm horizontal emittance. Injectors remain mostly unchanged: the 100 MeV linac feeds the 3 Hz booster synchrotron with extraction at 9 nm horizontal emittance and now 2.7 GeV to match the storage ring’s increased energy. Technical details and an overview of the SLS 2.0 commissioning are presented in separate contributions to this conference. This contribution focuses on the machine protection system challenges for the SLS 2.0**. These required the implementation of a sophisticated system including a fast beam dump kicker, dedicated beam dump, fast beam dump controller and a machine interlock system monitoring over 6000 signals. We discuss challenges encountered and lessons learned while commissioning this advanced machine protection system in parallel to commissioning of the new accelerator.
Paper: TUPM057
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-TUPM057
About: Received: 30 May 2025 — Revised: 02 Jun 2025 — Accepted: 03 Jun 2025 — Issue date: 05 Nov 2025
TUPM058
Simulation and optimization of nonlinear kicker injection for PAL-EUV storage ring
1282
The PAL-EUV storage ring has been designed to provide extreme ultra violet (EUV) beams, and is currently under commissioning. With a circumference of 36 m and an electron beam energy of 400 MeV, injection from the booster to the ring is achieved using a nonlinear kicker. Successful injection requires precise tuning of the kicker’s timing delay and maximum strength to match the injected beam’s conditions. This paper investigates the optimization method for these parameters and presents the results obtained through simulation.
Paper: TUPM058
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-TUPM058
About: Received: 28 May 2025 — Revised: 02 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 05 Nov 2025
TUPM060
Specification of insertion devices for ORION project at SIRIUS
1288
The pioneering ORION project will integrate a biosafety level 4 (BSL-4) laboratory with the SIRIUS synchrotron light source. The project includes three beamlines: TIMBÓ, HIBISCO, and SIBIPIRUNA, optimized for X-ray microscopy on biological materials. This study focused on evaluating Insertion Devices (IDs) for the TIMBÓ and HIBISCO beamlines, which demand high photon flux in the ranges of 3–20 keV and 16-40 keV, respectively. Achieving high photon energies with undulators in a 3 GeV synchrotron poses significant challenges. To address this, radiation emission calculations were performed for three ID types: in-air (IAU), in-vacuum (IVU), and cryogenically cooled permanent magnet (CPMU) undulators. With a numerical method based on SPECTRA* software, CPMUs were identified as optimal: a 2 m CPMU with a 14.6 mm period was identified for TIMBÓ, while HIBISCO ideal option is a 2 m CPMU with a 13.6 mm period. As a comparison of the types found for HIBISCO at 40 keV, CPMUs demonstrated approximately a 2.7x flux gain compared to IVUs, and IVUs about 3.8x the flux of IAUs. Further evaluations will consider also the impact on the electron beam dynamics and fabrication feasibility.
Paper: TUPM060
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-TUPM060
About: Received: 29 May 2025 — Revised: 03 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 05 Nov 2025
TUPM076
Refined FLUKA simulation model of neutrino-induced effective dose from a multi-TeV muon collider
1329
Most muons injected into a muon collider decay into an electron (or positron) and a neutrino-antineutrino pair, producing a narrow disk of high-energy neutrinos emitted tangentially to the beam in the collider plane. These neutrinos reach the Earth’s surface at distances far away from the collider. Vertical diffusion of the neutrino cone, reducing integrated neutrino flux at any surface exit point, has been proposed as mitigation technique. This study presents effective dose calculations performed with the FLUKA Monte Carlo code for various geometrical models, each representing conservative radiation exposure scenarios from neutrino flux emerging from the ground at specific distances from muon decay points. These scenarios correspond to different parts of the muon collider ring: bending sections and long straight sections housing experiments. Results are provided as effective doses for annual exposure scenarios with a 100% occupancy. Two muon beam energies are considered: 1.5 TeV and 5 TeV, with a more detailed approach applied to the higher energy.
Paper: TUPM076
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-TUPM076
About: Received: 27 May 2025 — Revised: 01 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 05 Nov 2025
TUPM114
An extraction scheme for future CEBAF FFA based energy upgrade
1407
Jefferson lab is considering an energy increase from current 12 GeV to 22 GeV for its CEBAF accelerator. This will be accomplished by recirculating 5-6 additional turns through two parallel CEBAF LINACs using an FFA arc at each end of the racetrack. The total recirculation turns would be 10 times, the first four turns use present conventional arcs to make the 180-degree bends from one LINAC to the other. However, the last 5-6 turns will all share a single beam line inside two FFA arcs. This reduces the footprint and the cost of the project significantly. On the other hand, having the trajectories of last 5-6 recirculating beams close to each other makes it challenging to extract beams from different passes with different energies. In this paper we will explain our present extraction system for 12 GeV, our challenges and limitations, and a possible extraction solution for the 22 GeV upgrade with the goal of extracting beam at different turns/energies to different experimental halls.
Paper: TUPM114
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-TUPM114
About: Received: 28 May 2025 — Revised: 31 May 2025 — Accepted: 31 May 2025 — Issue date: 05 Nov 2025
TUPS018
Synthesis of efficient ordered sodium potassium antimonide photocathodes via molecular beam epitaxy
1450
Alkali antimonide photocathodes exhibit high efficacy as photoemissive materials in electron sources. This proceeding explores the fabrication of thin, ordered films of sodium potassium antimonide via molecular-beam epitaxy (MBE) at the PHotocathode Epitaxy Beam Experiments (PHOEBE) laboratory at Cornell University. Utilizing a sequential deposition technique, the photocathodes are characterized in terms of both quantum efficiency (QE) and crystal structure with the goal of reducing the chemical and physical roughness. A spectral response from 400 to 700 nm demonstrates oscillations resulting from optical interference within the (SiN) substrate. Reflection high-energy electron diffraction (RHEED) patterns confirmed the successful growth of ordered crystal structures for the first time in a sodium potassium antimonide photocathode. Additionally, we investigated the photocathodes' sensitivity to oxidation, revealing their relative robustness compared to CsSb or KSb photocathodes. Notably, the incorporation of higher partial pressures of oxygen during growth improved QE and extended the operational lifetime of the photocathodes.
Paper: TUPS018
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-TUPS018
About: Received: 29 May 2025 — Revised: 02 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 05 Nov 2025
TUPS020
Hands on training with ASTRA at ISBA'24
1458
As part of the program of the seventh International School on Beam Dynamics and Accelerators (ISBA'24), we carried out hands-on training with the accelerator simulation code ASTRA. A selection of students used the intensive two-hour daily course to go from learning the basics of ASTRA to designing and optimizing their own accelerators. Here we report the details of training, the student projects and their presentations to their instructors and peers, and plans for future hands-on training programs.
Paper: TUPS020
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-TUPS020
About: Received: 27 May 2025 — Revised: 30 May 2025 — Accepted: 30 May 2025 — Issue date: 05 Nov 2025
TUPS026
Magnetic cycle optimisation in the CERN PS booster
1467
The PS Booster is the first synchrotron in the CERN proton accelerator complex, which delivers both high-brightness and high-intensity beams. Injection to the Booster is at a kinetic energy of 160 MeV, therefore space charge is a main limiting factors for beam quality. Maximising the longitudinal emittance and adding a second, and sometimes third, RF harmonic are measures to decrease the line density and so reduce the effect of space charge. Nonetheless, beam loss and transverse emittance growth are still unavoidable at low energy. Recent studies have been focused on the possibility of adapting the magnetic cycle to further reduce the impact of space charge. With a faster ramp, the time spent in a high space charge regime is reduced but the available RF voltage limits the bucket area. Alternatively, with a slower acceleration the RF bucket area and longitudinal emittance can be increased, which will reduce the magnitude of the space charge detuning, but more time will be spent at low energy. This contribution explores the effects of different magnetic cycles on the beam and the possibility of further optimising the booster acceleration.
Paper: TUPS026
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-TUPS026
About: Received: 19 May 2025 — Revised: 04 Jun 2025 — Accepted: 04 Jun 2025 — Issue date: 05 Nov 2025
TUPS027
RF power margin for operation with fixed-target in the CERN SPS
1471
The CERN Super Proton Synchrotron (SPS) Radio Frequency (RF) system was upgraded as part of the Large Hadron Collider Injector Upgrade (LIU) project, and now comprises six 200 MHz travelling wave structures, each fed by a separate RF power amplifier. While the upgrade was targeting the peak power for capture and acceleration of the beams for the High Luminosity LHC, it also brought an increase in the available average power for fixed-target beams. The additional power introduced margins which were first probed and exploited in 2024, when the SPS RF system had to be operated at majorly reduced power, during failures that blocked a single power amplifier or accelerating structure. Specific examples from the 2024 run are given, together with the mitigation measures. This contribution summarizes the efforts and results, highlighting in particular the improvements needed for the control of the RF voltage for easier switching to the degraded mode of operation and back, as well as the impact of the impedance of an undriven cavity.
Paper: TUPS027
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-TUPS027
About: Received: 27 May 2025 — Revised: 01 Jun 2025 — Accepted: 04 Jun 2025 — Issue date: 05 Nov 2025
TUPS029
Present status of RF system upgrade in the J-PARC MR
1479
J-PARC MR delivers 30 GeV proton beams to the neutrino facility and the hadron experimental facility, and an upgrade plan is underway to increase beam power by shortening the MR cycle time and increasing the number of particles per bunch. As a result, the beam power for neutrino experiments has achieved its original design value of 750 kW in 2023 and reached 800 kW in 2024. The target beam power of this upgrade plan is 1.3 MW for the Hyper-Kamiokande experiment.The current RF system consists of 9 fundamental cavities and 2 second harmonic cavities for a total of 11 RF systems, but it is necessary to add two more fundamental cavities to further shorten the MR cycle time. Preparations are underway to begin operation of the 10th RF system in 2025 and the 11th in 2027. In addition, as the number of particles increases, further beam loading compensation will be required, so we are also working on upgrading the RF source. We present the progress of the MR RF system upgrade.
Paper: TUPS029
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-TUPS029
About: Received: 28 May 2025 — Revised: 05 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 05 Nov 2025
TUPS030
Update of the tune ripple canceller system for slow extraction operation in the J-PARC MR
1483
In the slow extraction operation of the J-PARC Main Ring (MR), ensuring the uniformity of the extracted beam's time structure (“spill structure”) is crucial. One primary factor distorting the spill structure is the random fluctuation of the horizontal tune caused by current ripples in the main magnet power supplies. To address this issue, a system called the "tune ripple canceller" has been developed. This system calculates correction values for the horizontal betatron tune based on current ripples and controls the spill structure using fast-responding quadrupole magnets. In 2021, proof-of-principle beam experiments demonstrated its effectiveness in improving the spill structure. Subsequently, as part of the MR's power upgrade plan, the main magnet power supply system was upgraded by 2022. During this upgrade, the current measurement system was reconfigured, and the power spectrum of the current ripples was altered. As a result, it is now urgent to update the hardware and software of the tune ripple canceller system to align with these changes. This paper highlights updates, addresses challenges, and explores strategies to further enhance spill structure control in the MR.
Paper: TUPS030
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-TUPS030
About: Received: 28 May 2025 — Revised: 03 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 05 Nov 2025
TUPS032
Wien filter method for the "Quasi-frozen" spin lattice
1491
To study the electric dipole moment of light nuclei, it is necessary to maintain the direction of the spin along the particle's motion along the ring. The first obvious solution to this problem is to use elements with an electric field that rotates the spin in the direction opposite to the spin rotation in a magnetic field. The most successful solution in this case is the Wien filter, which ensures spin rotation while maintaining the co-direction of the spin and momentum. In this case, the ring structure consists of arcs with bending magnets and straight sections on which Wien filters with crossed electric and magnetic fields are installed. The paper considers various versions of a magneto-optical structure that implements the "Quasi-frozen" spin method for studying the electric dipole moment of deuterons and protons. This approach can be used in developing an upgraded Nuclotron structure.
Paper: TUPS032
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-TUPS032
About: Received: 25 Apr 2025 — Revised: 13 Oct 2025 — Accepted: 13 Oct 2025 — Issue date: 05 Nov 2025
TUPS035
TURBO – Enabling fast energy switching for hadron therapy with constant magnetic fields
1498
The energy layer switching time is a limiting factor for hadron therapy, precluding fast beam delivery and reducing treatment efficacy. For rapid energy switching the beam delivery system must be achromatic with zero dispersion over a large energy range. At the University of Melbourne, the TURBO project will utilise Fixed Field Accelerator techniques to demonstrate transport of a ±42% momentum spread beam around a 30° bend, with constant magnetic fields to eliminate the energy switching bottleneck. This will be demonstrated with an electrostatic Pelletron accelerator. A fast-switching energy degrader with thin diamond films has been designed to quickly change proton beam energies in the range 0.5-3.0MeV, covering the full clinical range when scaled up. A new design technique using nonlinear magnetic fields for energy-dependent focusing has been developed to minimise delivered beam variations. A novel method has been found to produce nonlinear permanent magnet arrays without custom magnets, enabling fast prototyping and reuse of magnets. With these innovations, the TURBO project will demonstrate rapid energy switching for hadron therapy to enable improvements in patient outcomes.
Paper: TUPS035
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-TUPS035
About: Received: 28 May 2025 — Revised: 03 Jun 2025 — Accepted: 04 Jun 2025 — Issue date: 05 Nov 2025
TUPS050
Mechanical design of a spin rotator for the ISIS Super MuSR beamline
1542
The Super MuSR spin rotators (SR) are electromagnetic devices with a horizontal dipolar magnetic field to rotate the muon spin by 34o and a perpendicular electric field that operates at +/-192 kV. The electromagnetic design was already presented elsewhere. The mechanical design is now complete, and the manufacturing of components has started, both of which are discussed here. The stainless steel vessel is 598 mm in diameter, 1.8 m long and has several ports along it. Most notably the large feedthrough port with a 15 mm inner radius to reduce the electrical fields. Mirror polished electrodes are mounted on ceramic insulators, optimised to shield the triple points from the high electric fields. The insulator mechanical design, manufacture & testing will also be discussed here. A high voltage test rig has been developed in parallel to test critical aspects such as the high voltage feedthrough, insulator design, vessel manufacture and surface finish requirements, before testing and assembling the main vessel. The magnet yoke is H-shaped with traditional racetrack coils. It was designed to be assembled around the around the vacuum vessel with kinematic feet for adjustment and alignment.
Paper: TUPS050
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-TUPS050
About: Received: 06 May 2025 — Revised: 13 Oct 2025 — Accepted: 13 Oct 2025 — Issue date: 05 Nov 2025
TUPS055
Simulations study of transverse wakefields in a dielectric wakefield acceleration scheme
1556
Novel acceleration schemes aim to address the need for higher acceleration gradients which enable to minimise the size and costs of particle accelerators. One of these novel accelerator schemes is the dielectric wakefield acceleration (DWA), where an electron bunch is accelerated by the longitudinal wakefields generated within a dielectric lined waveguide by a leading drive bunch with higher charge. The advantages of this novel acceleration method include high accelerating field strength, the simplicity of its structure and the stability of the wakefield generated which is synchronous with the electron bunch. However, the drive bunch propagation length, and hence the achievable energy gain, is limited by the effect of the transverse wakefields. These fields deflect the bunch towards the dielectric, leading to charge losses, a phenomenon commonly referred to as beam break-up (BBU) instability. This study uses simulations to investigate the transverse wakefields and their impact on the beam dynamics in a DWA scheme with drive and witness (main) bunches. The findings will be further explored experimentally at the CLARA facility in Daresbury Laboratory.
Paper: TUPS055
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-TUPS055
About: Received: 23 May 2025 — Revised: 13 Oct 2025 — Accepted: 13 Oct 2025 — Issue date: 05 Nov 2025
TUPS067
Development and operational performance of multi-alkali antimonide photocathodes
1578
Multi-alkali antimonide photocathodes, particularly potassium–cesium-antimonide, have gained prominence as photoemissive materials for electron sources in high-repetition-rate FEL applications due to their properties, such as low thermal emittance and high sensitivity in the green wavelength. To explore the potential of these materials in high-gradient RF guns, a collaborative effort was undertaken between DESY PITZ and INFN-LASA to develop and study multi-alkali photocathode materials. A batch of three KCsSb photocathodes and one NaKSb(Cs) photocathode was grown on molybdenum substrates using a sequential deposition method in the new preparation system at INFN LASA. These cathodes were successfully transferred and tested in the high-gradient RF gun at PITZ. Following the tests, a post-operational optical study was conducted on all the cathodes. Based on these findings, efforts are underway to optimize the fabrication recipes for KCsSb and NaKSb(Cs) photocathodes to achieve lower field emission and longer lifetimes. This contribution summarizes the experimental results of the production, operational performance, and post-usage analysis of the current batch of cathodes.
Paper: TUPS067
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-TUPS067
About: Received: 28 May 2025 — Revised: 03 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 05 Nov 2025
TUPS113
3D characterization of plasma density in capillary discharges for plasma-based accelerators
1608
Accurate characterization of plasma density profiles is vital for optimizing plasma-based accelerators, as density directly affects beam acceleration and quality. Plasma capillaries also serve as lenses and for beam guiding, highlighting their role in advanced accelerators. This study measures longitudinal and transverse density profiles of plasma capillaries, achieving 3D characterization using Stark broadening techniques. Two optical lines capture emitted plasma light. Parameters include gas flow rate, operating mode (pulsed/continuous), voltage, capillary type and geometry, gas type, and repetition rate, allowing evaluation of operational impacts on plasma density. Results show consistent density measurements across various positions, indicating the method's capability to capture spatial variations in plasma density. Understanding these profiles is crucial for developing and optimizing laser-driven and beam-driven plasma accelerators, as well as enhancing plasma lenses and beam guiding, enabling fine-tuning of parameters to maximize acceleration efficiency and control beam quality.
Paper: TUPS113
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-TUPS113
About: Received: 28 May 2025 — Revised: 02 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 05 Nov 2025
TUPS136
Characterization of the energy spectrum of a 30-MeV cyclotron-based quasi-monoenergetic neutron beam using a time-of-flight spectrometer
1633
We conducted time-of-flight (TOF) measurements to characterize the spectrum of a quasi-monoenergetic neutron beam driven by a 30-MeV proton cyclotron at the National Atomic Research Institute in Taiwan*. Neutrons were produced by irradiating 30-MeV protons onto a 1-mm-thick beryllium target. The developed TOF spectrometer comprised two 2-inch EJ-309 organic scintillators positioned 200 mm from the neutron beam port to detect gamma rays emitted from the target, and a 3-inch EJ-309 scintillator placed at a flight distance of 2940 mm to measure neutrons. As the signals of gamma-ray bursts triggered TOF measurements at an RF frequency of 73.13 MHz, repetitive distributions of coincidence events between gamma-ray and neutron-related signals were observed, resulting in an effective time window of 13.67 ns for measuring neutrons in the energy range of 16.19–30 MeV. The measured neutron spectrum exhibited a peak at 26 MeV, verifying the simulated spectrum obtained from an MCNP Monte Carlo model. Additionally, we developed a fast-timing scintillator module that measured the proton bunch duration as 0.97 ns, enabling accurate estimation of the energy resolution of the neutron spectrum.
Paper: TUPS136
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-TUPS136
About: Received: 24 May 2025 — Revised: 31 May 2025 — Accepted: 04 Jun 2025 — Issue date: 05 Nov 2025
WEXN1
Upgrade of KEK electron/positron injector LINAC using pulsed magnets and machine learning
1651
The KEK injector linac injects high-charge electron and positron beams into the high-energy-ring and low-energy-ring of SuperKEKB respectively. The linac also injects electron beams to the two light source rings, PF ring and PF-AR. We operate simultaneous top-up injections into the four rings by using many pulsed magnets. We have been upgrading the linac to attain the higher-quality beam injections for the SuperKEKB rings. In the summer of 2023, large-aperture quadrupole pulsed magnets have been newly installed upstream of the linac and driven by large-current pulse power supplies at markedly high electric efficiency. These new magnets bring the pulse-by-pulse optics changing to provide the high-quality beams. In order to cope with the complex beam injections to the four rings, we have introduced the automatic adjustment system by using machine-learning. The system surpasses human skill in beam adjustment and has resulted in significant increases in the amount of beam charge and beam transmission. We will report on the results of these upgrades.
Paper: WEXN1
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-WEXN1
About: Received: 28 May 2025 — Revised: 31 May 2025 — Accepted: 04 Jun 2025 — Issue date: 05 Nov 2025
WEAD1
20 years of CESR-B cavity operation at the CLS
1656
The Canadian Light Source (CLS), a 3<sup>rd</sup> generation synchrotron light source, has operated the CESR-B type superconducting radio frequency cavity since 2005. We report on 20 years of operating experience of the facility with this type of accelerating cavity.
Paper: WEAD1
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-WEAD1
About: Received: 28 May 2025 — Revised: 02 Jun 2025 — Accepted: 02 Jun 2025 — Issue date: 05 Nov 2025
WEAD2
High power RF testing of high temperature superconductors
1662
Superconducting materials such as niobium have been extremely useful for accelerator technology but require low temperature operation ~2 K. The development of high temperature superconductors (HTS) is promising due to their operating temperatures being closer to that of liquid nitrogen ~77 K. This work aims to determine the high-power RF performance of these materials at X-band (11.424 GHz). We have tested several types of rare earth barium copper oxide (REBCO) materials, such as films deposited by electron-beam physical vapor deposition, coated conductors soldered to a copper substrate, and solid pucks formed from powder. RF testing was done via a hemispherical TE mode cavity that maximizes the magnetic field and minimizes the electric field on a 2-inch sample region. We will report on surface resistance vs temperature measurements at low and high power,as well as RF testing of a pulse compression cavity lined with REBCO coated conductors.
Paper: WEAD2
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-WEAD2
About: Received: 28 May 2025 — Revised: 02 Jun 2025 — Accepted: 03 Jun 2025 — Issue date: 05 Nov 2025
WEAN2
Data-driven hysteresis compensation in the CERN SPS main magnets
1674
Magnetic hysteresis and eddy current decay continue to challenge beam quality and operational consistency in multi-cycling machines like the Super Proton Synchrotron (SPS) at CERN. Building on our previous work, this paper presents improvements in the data-driven approach for magnetic field modelling to enhance the reproducibility of SPS dipole and quadrupole fields and thus maintain stable beam parameters across all operational cycles. The method is based on feed-forward correction using magnetic field forecasting with machine learning. It now includes additional operational experience and demonstrates that the field error compensation can reliably be used in operation. This contribution proves that hysteresis compensation can be achieved without a feedback system based on expensive installations with online field measurements in reference magnets. The performance improvements achieved by eliminating the need for manual adjustments and reducing time- and energy-consuming accelerator pre-cycles are presented. The paper also sets the stage for future application in higher-order magnets, like sextupoles and octupoles, as well as on other CERN synchrotrons.
Paper: WEAN2
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-WEAN2
About: Received: 27 May 2025 — Revised: 04 Jun 2025 — Accepted: 04 Jun 2025 — Issue date: 05 Nov 2025
WEAN3
Supersonic gas curtain-based in-vivo transverse beam profile monitoring for medical accelerators
1678
To ensure patient safety, treatment effectiveness, and facility efficiency, each ion beam therapy facility requires a complete online characterization of the charged particle beam. Existing dosimetry methods are either limited in the information they provide or invasive to the beam, highlighting the need for new in-vivo dosimetry solutions. Since 2015, the QUASAR Group at the Cockcroft Institute, UK has been developing non-invasive beam monitors for medical accelerators. Accurate monitoring of the transverse beam profile is the first step toward achieving in-vivo dosimetry. The monitor, under development, utilizes a supersonic gas curtain that interacts with the charged particle beam, using the resulting impact ionization to measure the transverse beam profile. A prototype monitor was successfully tested for proof-of-concept measurements at the Dalton Cumbrian Facility’s pelletron accelerator (UK). Measurements were conducted using various beam parameters with both proton and carbon ion beams. This contribution presents the monitor's design and operating principle, experimental results from the measurements, and additional planned improvements aimed at achieving in-vivo dosimetry.
Paper: WEAN3
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-WEAN3
About: Received: 21 May 2025 — Revised: 02 Jun 2025 — Accepted: 02 Jun 2025 — Issue date: 05 Nov 2025
WEPB021
Design of a 2300 W 352 MHz solid-state amplifier module with integrated EtherCAT interface for monitoring and control
1771
For multi-unit RF amplifier systems, a 2300 W solid-state RF power amplifier module with integrated EtherCAT and USB interface has been developed. The RF amplifier section is constructed from the latest LDMOS from Ampleon with a power of 2300 W at an efficiency of 72 % and is fully shielded and offers space for adding a driver amplifier or phase shifter circuit. The module is equipped with a DIN 7/16 output connector and an N-type input connector and is housed in a metal housing of 200 x 95 x 80 mm. The cooling of the RF LDMOS is done via a CNC milled copper cooling plate that is gold-plated. The gold layer prevents chemical oxidation with other aluminum parts such as an aluminum main plate. In a multi-unit system, the EtherCAT interface provides lightning-fast and synchronous control and monitoring of parameters such as supply voltage and current, heat sink and LDMOS temperature, forward and reverse RF power. Outside the EtherCAT environment, the USB interface can be used in combination with a Windows GUI. Eight LEDs are available as visual indicators. The entire process of design, assembly and testing takes place in the Netherlands, which guarantees quality and traceability.
Paper: WEPB021
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-WEPB021
About: Received: 16 Apr 2025 — Revised: 13 Oct 2025 — Accepted: 13 Oct 2025 — Issue date: 05 Nov 2025
WEPB024
Linear weight optimization of local magnetic field sensors for the integral field measurement in accelerator magnets
1780
The measurement of the integral magnetic field in accelerator magnets is crucial for the precise control and operation of particle accelerators. Traditional methods often rely on a fixed distribution of magnetic field sensors or long integral coils. Nonetheless, integral coils are sometimes unavailable in the magnet bore. This study presents an approach to enhance integral magnetic field measurements through the linear weight optimization of local magnetic field sensors. Our methodology involves strategically placing and weighing sensors within the magnet to minimize errors between the measured and actual integral magnetic fields for different powering cycles. We employ optimization algorithms to determine the optimal linear combination of sensor readings that best approximates the integral field. This process improves measurement accuracy and reduces the number of required sensors. We validate our approach through simulation and experimental setups. The results indicate that our optimized sensor placement and weighting scheme can be effectively implemented in existing accelerator systems, offering a scalable solution for enhancing particle accelerator performance.
Paper: WEPB024
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-WEPB024
About: Received: 28 May 2025 — Revised: 05 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 05 Nov 2025
WEPB025
The study of the eddy current-type septum magnet for fast extraction in J-PARC MR
1784
The eddy current type septum magnets (Eddy-septa) are used for fast extraction in J-PARC MR from 2022. Currently, the operation of the Eddy-septa is very stable. However, we have some still technical issue. One is an output pulsed current measurement by current transfers. The peak value of the output pulsed current is measured pulse by pulse and the measured value is used for a feedback system using by PXI system for long-term stability. The output current is also measured with different current transfer in same time for double checking. However, we don't have good reproducibility with the measurement result by the PXI feedback system yet. We have found the noise which are generated by the kicker magnets and extraction beam in 2023, thus, we started to investigate the detail of the process of generation and method of removal. Second is residual field along the circulating beam line in Eddy-septa. We had reported the leakage field by exciting current on the circulating beam line and the strength was very small. In summer of 2023, we found large residual field on the same line. In this presentation, we report the status of measurement of output current, and residual field.
Paper: WEPB025
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-WEPB025
About: Received: 27 May 2025 — Revised: 03 Jun 2025 — Accepted: 04 Jun 2025 — Issue date: 05 Nov 2025
WEPB029
Transient finite-element simulations of fast-ramping normal-conducting magnets for a 10 TeV muon collider
1799
Ongoing conceptual studies for a 10TeV muon collider identified rapid cycling synchrotrons as major engineering challenge. Due to the muon’s short lifetime of only 2.2µs at rest, normal-conducting bending magnets with field rise rates of well beyond 1kT/s are indispensable to support accordingly fast acceleration cycles. Energies of 100MJ will be interchanged between magnets and capacitor banks within few milliseconds. Accurate models of the magnets are thus required to optimize the overall system performance. The non-uniform temperature distribution in the magnet strongly affects material properties like the electrical conductivity of copper and must therefore be considered in the electromagnetic field problem. This contribution presents recent advancements in addressing this multi-physical problem by using problem-specific finite-element tools allowing to describe the inherently transient behavior. The ferromagnetic yoke is accurately resolved by using a novel combination of a Bergqvist hysteresis and a homogenized eddy current model. Finally, different magnet design concepts are compared in terms of material costs, magnetic energy, losses, field quality and temperature buildup.
Paper: WEPB029
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-WEPB029
About: Received: 22 May 2025 — Revised: 31 May 2025 — Accepted: 31 May 2025 — Issue date: 05 Nov 2025
WEPB030
Efficient nonlinear simulations of the fast corrector magnets for PETRA IV
1803
Fast orbit feedback systems are an important component in fourth-generation synchrotron radiation sources such as PETRA IV at DESY in Hamburg, Germany. These control systems are designed to stabilize the particle orbit, i.e., to correct deviations from the design orbit due to various disturbances. To that end, such a system employs fast orbit corrector magnets, which must be powered at frequencies up to the kilohertz range. This leads to significant eddy current effects that must be predicted via finite element simulations. Therefore, extensive simulation studies have already been conducted. These simulations did not, however, consider the magnetization curve’s nonlinearity since doing so requires prohibitive computational effort when using commercial software. Hence, we have constructed a dedicated method, based on a combination of the harmonic balance finite element method and homogenization schemes, to enable nonlinear simulations. This contribution outlines the general idea and application of our method to the corrector magnets of PETRA IV and presents the most important findings regarding the impact of the nonlinear magnetization curve on the magnet’s performance.
Paper: WEPB030
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-WEPB030
About: Received: 05 May 2025 — Revised: 30 May 2025 — Accepted: 30 May 2025 — Issue date: 05 Nov 2025
WEPB042
Third order resonance correction using new Trim-S system in J-PARC MR
1826
In the Japan Proton Accelerator Research Complex (J-PARC) Main Ring (MR), to address the issue of resonance correction for third-order resonances in both on- and off-momentum particles, an upgrade project utilizing 24 Trim-S units has been proposed based on numerical simulations. As a first step in verifying its effectiveness, four additional Trim-S (new Trim-S) power supplies, configured with a System-on-Chip (SoC) Field Programmable Gate Array (FPGA) controller, have been installed. The performance of the new system was experimentally verified by correcting the resonance using these 4 new Trim-S units. Beam loss was successfully reduced compared to that with the original Trim-S system, demonstrating the effectiveness of the new system.
Paper: WEPB042
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-WEPB042
About: Received: 14 Apr 2025 — Revised: 31 May 2025 — Accepted: 02 Jun 2025 — Issue date: 05 Nov 2025
WEPB043
A study on the pattern waveform high-voltage power supply for the rapid cycling induction synchrotron
1830
The application of a 10 Hz repetitive induction synchrotron (IS) to the next generation of heavy ion therapy drivers is under investigation* **. The IS is characterized by the use of a pulse voltage to accelerate the beam, but until now, due to technical limitations, the magnitude of the pulse voltage could not be perfectly matched to the acceleration conditions. Instead, a pulse density modulation method has been adopted. However, this method inevitably induces synchro-beta coupling, which increases beam emittance. To overcome this problem, we develop a pattern-voltage dc power supply in which the output voltage waveform has a sinusoidal half-wave shape that matches the acceleration conditions. First, a mini-model was fabricated, and comparative experiments were conducted with three different circuit schemes: (A) a bipolar-controlled full-bridge circuit, (B) a unipolar-controlled full-bridge circuit, and (C) a series connected half-bridge circuit. This paper describes the results of these tests and issues for future study.
Paper: WEPB043
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-WEPB043
About: Received: 28 May 2025 — Revised: 02 Jun 2025 — Accepted: 02 Jun 2025 — Issue date: 05 Nov 2025
WEPB044
Development of a modular corrector magnet power supply with N+1 redundancy for TPS facilities
1833
This study presents a multi-module parallel current output system based on the correction magnet power supplies (CMPS) of the TPS storage ring. An N+1 re-dundant control interface card was designed to enable high-current, bipolar modular parallel output. The system integrates external DCCTs and current feed-back signals from the internal module. After PI com-pensation, these feedback signals are compared with the reference current to compute correction values distributed to each CMPS for closed-loop current con-trol. Each CMPS module provides an output of ±48 V/±10 A, and up to eight modules can be connected in parallel for a maximum output of ±80 A. Experimental results demonstrate long-term output current stability within 0.6 mA (or 7.5 ppm), with current noise spectra primarily below 500 µA. The system also supports N+1 redundancy and bipolar current output, offering a stable and flexible solution for magnet power control.
Paper: WEPB044
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-WEPB044
About: Received: 20 May 2025 — Revised: 13 Oct 2025 — Accepted: 13 Oct 2025 — Issue date: 05 Nov 2025
WEPB055
Design and development a measurement system for magnetic tuning of undulator magnets
1861
The permanent-magnet in-vacuum undulator technique is critical for the Taiwan Photon Source(TPS) at the National Synchrotron Radiation Research Center(NSRRC). Before installing the magnet arrays in the vacuum chamber, the phase error of the undulator is optimized by adjusting the magnetic field. Optimizing phase errors is a complex and time-consuming task. The conventional measurement method involves using Hall probes to measure the magnetic field and a stretched-wire(SW) to measure the integral field of the undulator. In this work, we propose a method for tune the local magnetic field by utilizing the correlation between the gap and the magnetic field. We have demonstrated that using gap sensors allows us to more effectively determine whether to tune the magnetic field of the upper or lower magnet array. Additionally, we have demonstrated for the first time the use of the pulsed wire measurement (PWM) method for magnetic sorting.
Paper: WEPB055
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-WEPB055
About: Received: 14 May 2025 — Revised: 01 Jun 2025 — Accepted: 13 Oct 2025 — Issue date: 05 Nov 2025
WEPB061
High repetition tests of a pulsed power supply using SiC-MOSFETs for a fast kicker system in KEK-PF
1880
A pulsed power supply (PPS) using SiC-MOSFETs is an essential component in the camshaft-bunch system at KEK-PF *. The system requires the PPS to generate half-sine pulses with a peak current of 500 A, a pulse width of 200 ns, and a repetition rate (rep-rate) of 800 kHz. We have developed a prototype PPS consisting of a resonant circuit (RC) to generate half-sine pulses with a SiC-MOSFET switching module (SWM). The SWM, manufactured by NexFi Technology, has a rated voltage of 24 kV and a maximum rep-rate of 400 kHz. The main challenges in RC development were to reduce the charging time of the RC and power consumption during high-frequency operation. Additionally, film capacitors used in a previous prototype * required replacement because their permittivity had degraded during high-frequency operation. To overcome these challenges, we designed a RC with an energy recovery circuit, which reduced the charging time to 1 µs and power consumption by 90%. To ensure reliability, the film capacitors were replaced with vacuum capacitors. This report presents the prototype design, performance tests at a rep-rate of 400 kHz, and evaluation of long-term reliability at a rep-rate of 100 kHz.
Paper: WEPB061
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-WEPB061
About: Received: 28 May 2025 — Revised: 03 Jun 2025 — Accepted: 04 Jun 2025 — Issue date: 05 Nov 2025
WEPB064
Development of a 13 kV SiC-MOSFET-based pulsed power supply for evaluating metallic materials under high electric fields
1890
To perform high electric field experiments for evaluating the vacuum breakdown characteristics of accelerator materials, we have developed a high-voltage pulsed power supply capable of providing a 10 kV peak voltage, 1 µs pulse width, and 1 kHz repetition rate. This system is designed to reliably apply intense fields to metallic electrodes with load capacitances up to 650 pF. To ensure operational reliability and prevent potential equipment damage, it incorporates an interlock system that halts operation when load short-circuits or external interlock signals are detected. By employing a 13 kV SiC-MOSFET developed under the Tsukuba Power Electronics Constellation (TPEC), we reduced the number of components and improved overall reliability. This report presents the technical features and performance of the power supply, demonstrating that it meets the operational specifications necessary for evaluating candidate materials under high electric field conditions.
Paper: WEPB064
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-WEPB064
About: Received: 28 May 2025 — Revised: 04 Jun 2025 — Accepted: 04 Jun 2025 — Issue date: 05 Nov 2025
WEPB065
Development of compact ultra-high power pulsed power supply
1893
Currently, pulsed power supply systems with output power of several GW, output voltage of several hundred kV, and pulse width of 100 ns are difficult to miniaturize and portability is a limitation for industrial applications. We are developing a pulsed power supply with an output power of 4 GW, an output voltage of 200 kV, and a pulse width of 100 ns, which is 1/20th the mass of conventional products, in order to solve this limitation. In this presentation, we will give an overview of the system design and the current status of the development.
Paper: WEPB065
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-WEPB065
About: Received: 27 May 2025 — Revised: 02 Jun 2025 — Accepted: 02 Jun 2025 — Issue date: 05 Nov 2025
WEPB067
High-power, high-repetition-rate X-band power source at X-LAB, the X-band laboratory for accelerators and beams at the University of Melbourne
1896
The X-LAB has been commissioned at the University of Melbourne. A key project within this laboratory involves rehoming half of the CERN high-gradient X-band test stand, XBOX3, now known as Mel-BOX. This initiative aims to validate the performance of high-gradient traveling wave accelerating structures operating at a frequency of 12 GHz. Mel-BOX is employed to evaluate the performance of these accelerating structures under high-power pulsed RF conditions. Two TD24 high-gradient structures, previously conditioned at CERN, were reconditioned at X-LAB after being shipped and stored for five years. Additional components have also been tested, including a compact pillbox-type RF window with traveling waves in ceramic, SLED-I type pulse compressors with a novel piston design, and high-power loads fabricated via 3D titanium printing and 1-meter-long stainless steel. As with XBOX3, Mel-BOX utilizes the combined power of two high-average-power klystron units to feed two test slots at a repetition rate of up to 400 Hz. Additionally, there are plans to leverage this technology as a foundation for developing compact accelerators for medical and university applications.
Paper: WEPB067
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-WEPB067
About: Received: 28 May 2025 — Revised: 05 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 05 Nov 2025
WEPB076
RF design for optimal high-gradient performance of a four-quadrant structure for the ASTERIX project
1904
The ASTERIX project, funded by CSN5 and proposed at INFN-LNF, aims to demonstrate a practical, meter-long X-band RF structure for linear accelerators made of hard copper and divided into four quadrants. The prototypes will be constructed by TIG welding. In the first year of the feasibility study, we will design the RF cavities for two full structures working at single-bunch and multi-bunch operation. In this paper, structures operating at single-bunch mode for ASTERIX are numerically studied. The surface field enhancements of the quadrant-type accelerating structures are the most challenging issue to be resolved. The geometry near the gap between four quadrants is carefully optimized and obtain low surface field while maintaining high RF performance.
Paper: WEPB076
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-WEPB076
About: Received: 28 May 2025 — Revised: 05 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 05 Nov 2025
WEPB078
LIPAc RF system commissioning: busting one EMC problem at a time
1910
Addressing electromagnetic compatibility (EMC) issues at the design stage is important. However, for a prototype like the Linear IFMIF Prototype Accelerator (LIPAc) and its RadioFrequency (RF) system providing over 2 MW of RF power, problems during the commissioning have to be expected. Random interlocks and probability of occurrence increasing with the number RF modules, the power level or the duty cycle are often evidences of EMC problems, sometimes known as RF noise. Those conditions are difficult to reproduce by the manufacturers and if no margins are considered, they need to be addressed by a dedicated team onsite*. Two solved EMC problems will illustrate the basics of the mitigation strategy: locate and stop the RF noise at the source or protect the victims from the RF noise. The first approach is applied on the air cooling: the noise from an inverter, driving a motor over tens of meters of cables, affected multiple systems sharing the same cable tray and had to be fixed at its source. The second way is applied on the tetrodes high voltage input monitor, affected by RF leaking probably from the tetrode: a source difficult to stop that called for a protection of the victim.
Paper: WEPB078
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-WEPB078
About: Received: 26 May 2025 — Revised: 02 Jun 2025 — Accepted: 03 Jun 2025 — Issue date: 05 Nov 2025
WEPB099
Advancements in LINAC performance for enhanced stability and control: Integration of the Libera LLRF systems into the ScandiNova modulators
1929
For years, Instrumentation Technologies and ScandiNova have developed advanced products to optimize RF performances in LINAC applications. In 2024, the companies began integrating the Libera LLRF system into ScandiNova modulators during assembly. This innovation enables the modulators to offer enhanced operational flexibility and improved performances. This paper will focus on mechanical integration and performance results. The integrated system enables real-time monitoring of critical signals such as drive power to the RF amplifier and klystron, as well as forward and reflected klystron power. Performance metrics include amplitude stability <0.01% RMS and phase stability <0.01° RMS. Experimental results are presented using a ScandiNova modulator with an Sband klystron and a standard Sband Libera LLRF. Pulse-to-pulse stability measurements demonstrate consistency between conventional electrical methods and RF-based methods, achieving stability in the 10 ppm range. Electromagnetic compatibility tests confirm that the modulators do not interfere with the LLRF system. Additionally, new tools are introduced to identify components with the greatest impact on phase stability.
Paper: WEPB099
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-WEPB099
About: Received: 24 May 2025 — Revised: 30 May 2025 — Accepted: 31 May 2025 — Issue date: 05 Nov 2025
WEPB100
Development of ultra high power compact X-band pulse compressor
1933
We have developed a new SLED-type RF pulse compressor for powering ultra-high gradient X-band photoinjectors with pulse lengths shorter than 10 ns. Klystrons capable of generating these short pulses at multi-MW levels are non-existent. However, RF pulse compression is an alternative technique used to increase klystron output peak power at the cost of pulse length. Over the years, we have developed numerous pulse compression systems, including super-compact SLEDs for X-band transverse deflectors at SLAC’s LCLS and LCLS-II. Our new compact pulse compressor uses spherical cavities with axially-symmetric TE modes which have no electric field on the cavity surface. This allows our new SLED to potentially achieve higher peak RF power compared to the LCLS-II SLEDs. We present the design of this SLED composed of two spherical cavities and a waveguide hybrid with TE01 circular waveguide ports. During high power test this SLED produced peak RF power up to 317 MW.
Paper: WEPB100
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-WEPB100
About: Received: 28 May 2025 — Revised: 05 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 05 Nov 2025
WEPM019
Data driven methods to recognize patterns in EIC weak-strong simulation
1996
Beam-Beam simulations are currently being studied in preparation for future EIC experiments to study beam-beam effects and, in turn, maximize luminosity. Weak-strong methods are studied for single-particle dynamics during collision. 1 million macro-particles for 1 million turns are typically tracked, corresponding to only 10 seconds in the EIC. The goal of this study is to predict beam properties over the scale of hours. A potential solution focuses on using data-driven methods such as machine learning methods to analyze and extend the insights of the beam properties such as long-term nonlinear effects. This would aid in long-term predictions where results would be more efficiently acquired than a typical tracking simulation. Some limitations such as inaccurate predictions and spatial complexity are also discussed. These methods can then be applied to strong-strong simulations in the future studies.
Paper: WEPM019
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-WEPM019
About: Received: 28 May 2025 — Revised: 01 Jun 2025 — Accepted: 02 Jun 2025 — Issue date: 05 Nov 2025
WEPM028
Beam instability suppression during debunching process through slippage factor tuning in the J-PARC Main Ring
2016
The J-PARC Main Ring achieves a high extraction efficiency of 99.5% during 30 GeV slow extraction at the current beam power of 80 kW. However, at beam powers above 30 kW, we observed ring-wide beam losses due to transverse beam instability associated with vacuum pressure rises and electron cloud effects, which are believed to be triggered by longitudinal microwave structures. To achieve stable operation at 80 kW, we implemented phase offset injection into RF buckets and two-step RF voltage reduction during debunching. For planned higher-power operations, we propose tuning the slippage factor to suppress the microwave structures during debunching. The Main Ring features a unique imaginary transition gamma lattice, and we discovered that the slippage factor can be adjusted using appropriate combinations of four quadrupole families in the arc sections while maintaining the operating tune and achromatic conditions in the long straight sections. Such slippage manipulation would be impossible in a ring with a conventional FODO lattice. The slippage factor can be ramped from its nominal value to a suppressing value during acceleration.
Paper: WEPM028
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-WEPM028
About: Received: 28 May 2025 — Revised: 01 Jun 2025 — Accepted: 01 Jun 2025 — Issue date: 05 Nov 2025
WEPM033
Energy ramping simulation for TPS booster ring
2036
The Taiwan Photon Source (TPS) booster ring accelerates electron beams from the linear accelerator (lin-ac) output energy of 150 MeV to 3 GeV for storage ring injection. In the event of partial RF station failure in the linac, the available beam energy may be reduced to 100 MeV. Preliminary machine tests have demonstrated multi-turn beam circulation in DC mode and successful acceleration from 127.5 MeV to 3GeV. Beam dynamics simulations using elegant evaluate the effects of dipole field errors, magnet multipole and alignment errors, chamber aperture constraints. Additionally, space charge effects at 100 MeV, due to the low relativistic factor, could lead to incoherent tune shifts, and potential beam loss. This study investigates the feasibility of operating the TPS booster at 100 MeV injection and ramping to 3 GeV with a focus on beam dynamics considerations
Paper: WEPM033
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-WEPM033
About: Received: 28 May 2025 — Revised: 04 Jun 2025 — Accepted: 04 Jun 2025 — Issue date: 05 Nov 2025
WEPM047
Xnlbd: A new Python package for the analysis of non-linear beam dynamics phenomena
2081
Nonlinear effects in particle accelerators have historically been treated as harmful influences that necessitate various mitigation schemes. Therefore, the simulation tools available are largely focused on identifying and correcting resonances. However, recent advances proved that nonlinear beam dynamics enables new techniques for manipulating particle beams and can characterise diffusion and chaos in particle accelerators. The simulation tools currently available for these purposes are difficult to integrate across different frameworks. This paper presents Xnlbd, a new Python package extending the Xsuite simulation framework, which aims to provide a unified set of tools for analysing nonlinear beam dynamics phenomena. It allows the visualisation of highly nonlinear phase spaces, the efficient finding of both stable and unstable fixed points and separatrices, the calculation of resonance driving terms and normal forms, and the computation of dynamic indicators for the detection of chaotic motion.
Paper: WEPM047
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-WEPM047
About: Received: 20 May 2025 — Revised: 31 May 2025 — Accepted: 01 Jun 2025 — Issue date: 05 Nov 2025
WEPM061
Dynamic aperture models for a time-varying high luminosity LHC lattice
2105
The evaluation of dynamic aperture (DA) under time-dependent variations of lattice parameters is essential for understanding the long-term stability of particle motion in the Large Hadron Collider (LHC) and enhancing the future performance of the High-Luminosity LHC (HL-LHC). In this work, we develop DA models that address the complexities introduced by time-varying effects, with a focus on the operational challenges posed by luminosity levelling. Building on established DA scaling laws, we aim at capturing the impact of evolving machine conditions during levelling. An initial simulation study is presented that compares the effects on DA of different levelling schemes that are expected to be routinely used during the HL-LHC operation, providing key insight into extending current DA models to accommodate time-dependent perturbations.
Paper: WEPM061
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-WEPM061
About: Received: 28 May 2025 — Revised: 30 May 2025 — Accepted: 01 Jun 2025 — Issue date: 05 Nov 2025
WEPM067
Introducing an open-source 3D time-domain electromagnetic wakefield solver for beam-coupling impedance simulations
2117
The determination of electromagnetic wakefields and their impact on accelerator performance is a longstanding challenge in accelerator physics. These wakefields, induced by the interaction between a charged particle beam and the surrounding vacuum chamber structures, significantly affect beam stability and power dissipation. Accurate characterization of these effects via beam-coupling impedance is crucial for predicting and mitigating performance limitations. While analytical methods are sufficient for simple geometries, realistic accelerator components require full-wave, three-dimensional numerical solutions of Maxwell's equations. In alignment with CERN's Open Science initiative, this contribution introduces an open-source 3D electromagnetic time-domain solver specifically designed for computing wake potentials and impedances in arbitrary geometries. The solver’s numerical implementation, optimized for CUDA-enabled GPUs, is presented and validated through benchmarks against established commercial codes. By fostering a collaborative framework, this solver aspires to address emerging challenges in accelerator design.
Paper: WEPM067
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-WEPM067
About: Received: 27 May 2025 — Revised: 30 May 2025 — Accepted: 01 Jun 2025 — Issue date: 05 Nov 2025
WEPM068
Broadband characterization of the CERN-SPS driving and detuning impedance
2121
The CERN-SPS transverse impedance model plays an important role in predicting beam stability and guiding machine operation. This work advances the benchmarking of the SPS vertical impedance model through experimental investigations of mode-zero instability growth rates and intensity-dependent tune shifts as a function of chromaticity. Building on insights from previous measurement campaigns, this study aims to address persistent discrepancies in the high-frequency domain associated with the real driving component of the effective impedance. The 2024 campaign incorporates growth rate measurements at varied transverse tunes to eliminate potential resonance crossing effects that could artificially enhance the high-frequency mismatch. The imaginary component of the transverse impedance is likewise explored by correlating intensity-dependent tune shifts with chromaticity variations. By combining all measurements and beam dynamics simulation results, the driving and detuning impedance model of key elements will be refined, offering improved predictive capabilities for the current SPS transverse impedance model.
Paper: WEPM068
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-WEPM068
About: Received: 27 May 2025 — Revised: 04 Jun 2025 — Accepted: 04 Jun 2025 — Issue date: 05 Nov 2025
WEPM093
A particle-in-cell implementation of intra-beam scattering for Xsuite
2191
Intra-Beam Scattering (IBS) remains one of the primary mechanisms of emittance blow-up and performance degradation in the Large Hadron Collider (LHC) accelerator chain. The phenomenon is particularly relevant following the recent injector upgrades to achieve the high-brightness beams required for the High Luminosity LHC (HL-LHC) era. Traditional IBS models, as those already implemented in Xsuite, rely on the assumption of Gaussian beam distributions. However, observations in the CERN complex indicate the presence of q-Gaussian beam profiles, for which these models do not accurately reproduce IBS effects. To address this limitation, a Particle-In-Cell (PIC) approach was developed that operates independently of distribution assumptions. This methodology behind the PIC approach, and benchmarks against existing models as well as experimental data from the LHC are presented in this contribution. Current limitations are also discussed.
Paper: WEPM093
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-WEPM093
About: Received: 22 May 2025 — Revised: 04 Jun 2025 — Accepted: 04 Jun 2025 — Issue date: 05 Nov 2025
WEPM099
Investigation of the microwave instability at MAX IV laboratory in combination with intra-beam scattering
2207
With the increasingly challenging parameters in 4th generation synchrotron light sources, collective effects causing instabilities are putting even stronger limitations on the area of stable operation. The microwave instability (MWI) is a longitudinal single-bunch instability driven by the geometric and the resistive-wall impedances. While the instability typically does not result in a beam loss, the resulting turbulent dynamics are accompanied by an increased energy spread and therefore deteriorate the light source performance. The threshold current depends on different beam parameters and can, without mitigation, for recently upgraded or currently under design light sources, be as low as or lower than the intended design current per bunch. At the same time, the instability threshold is also influenced by other collective effects such as the intra-beam scattering (IBS). The influence of the IBS on the microwave instability has been studied for the 3 GeV storage ring at the MAX IV laboratory. The presented experimental results show the expected influence on the MWI threshold by the coupling strength due to the resulting changes in the IBS.
Paper: WEPM099
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-WEPM099
About: Received: 28 May 2025 — Revised: 04 Jun 2025 — Accepted: 04 Jun 2025 — Issue date: 05 Nov 2025
WEPM111
Experimental validation of parallel quadrupole beam-based alignment at KARA
2229
The Karlsruhe Research Accelerator (KARA), a synchrotron light source and test facility, at the Karlsruhe Institute of Technology (KIT), offers excellent conditions for testing different Beam-Based Alignment (BBA) approaches. Classical BBA approaches estimate the offset between the magnet and the closest BPM for one magnet at a time, and the required time for the BBA scales linearly with the number of magnets. Therefore, this approach is unsuitable for large storage rings like the Future electron-positron Circular Collider (FCC-ee). The time required is reduced using parallel BBA, where the magnet offset for several magnets is determined simultaneously. In this contribution, we compare new methods of parallel and individual BBA for quadrupoles at KARA. The measurement results are complemented with simulations using Xsuite and optics measurements.
Paper: WEPM111
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-WEPM111
About: Received: 09 May 2025 — Revised: 04 Jun 2025 — Accepted: 04 Jun 2025 — Issue date: 05 Nov 2025
WEPS007
Measurement of coherent synchrotron frequencies under conditions close to the Robinson limit at the Aichi Synchrotron Radiation Center
2248
Past measurements* of coherent synchrotron frequencies at the Photon Factory storage ring revealed that the behavior of measured coherent frequencies could not be well explained with standard 4th-order characteristic equation under conditions close to the Robinson limit. To investigate whether similar phenomenon occurs in other storage rings, we measured the coherent synchrotron frequencies at a 1.2-GeV electron storage ring of Aichi Synchrotron Radiation Center as a function of the cavity voltage and the beam current. At beam currents higher than about 200 mA, we observed double peaks, one with a frequency higher than the incoherent synchrotron frequency and one with a lower frequency, that can correspond to two independent solutions of the 4th-order characteristic equation. Our preliminary analysis indicated that the frequencies of lower-frequency peak did not agree well with those predicted by the characteristic equation. We also observed that under a condition very close to the Robinson limit, the beam exhibited strong longitudinal coherent self-excited oscillation without beam dump. We present these measurement results and updated analysis.
Paper: WEPS007
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-WEPS007
About: Received: 27 May 2025 — Revised: 13 Oct 2025 — Accepted: 13 Oct 2025 — Issue date: 05 Nov 2025
WEPS025
Design, manufacturing and validation of fast-ramping alpha magnet for interleaving operation at ANL APS
2298
RadiaBeam has designed and manufactured a fast-ramping alpha magnet (FRAM) that is developed for interleaved operation at the Advanced Photon Source (APS) at Argonne National Laboratory. This interleaving operation requires the alpha magnet to stably complete a 5 s long cycle with a 100 ms ramp-up, 1s nominal field output and a 100 ms ramp-down. A laminated yoke is used to minimize eddy currents, ensure fast field response times and reduce core-loss during operation. The magnet has been measured by a Hall probe at Radiabeam and at Argonne, demonstrating 2.75 T/m maximum field gradi-ent within a 10 cm x 14 cm good field region in both DC and pulse modes.
Paper: WEPS025
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-WEPS025
About: Received: 28 May 2025 — Revised: 03 Jun 2025 — Accepted: 03 Jun 2025 — Issue date: 05 Nov 2025
WEPS041
GPU accelerated longitudinal phase space tomography
2329
Longitudinal tomography is widely used in the CERN synchrotrons as an essential beam diagnostics tool. In recent years, more complex applications of phase space tomography, such as voltage calibration and multi-bunch tomography, have been explored. For these applications, large numbers of reconstructions are required, and computation time has a significant impact on usability. The current implementation is Python based, with the numerically intensive components written in C++. To further increase performance, a GPU-accelerated version has been developed using CuPy and CUDA. The most computationally demanding parts of the algorithm can now be run on the GPU, whilst maintaining the Python interface for maximum flexibility. Performance benchmarks showed speedups up to a factor of 35 in the scope of the entire application and even higher values when only considering the computationally intensive parts. This contribution discusses the implementation of GPU tomography as well as the additional performance improvements it enables.
Paper: WEPS041
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-WEPS041
About: Received: 15 May 2025 — Revised: 02 Jun 2025 — Accepted: 02 Jun 2025 — Issue date: 05 Nov 2025
WEPS043
Achieving diverse beam modes with modelling and optimisation for the versatile SRF photoelectron gun at SEALab
2337
The SEALab facility in Berlin is home to an R\&D superconducting radio-frequency (SRF)photoinjector setup and beamline. Designed to support multiple varied applications - ranging from Energy Recovery Linac (ERL) to Ultrafast Electron Diffraction (UED) and Electron-Beam Water Treatment (EBWT) - SEALab requires flexible, high-precision tuning to support these diverse beam modes. These applications span over three orders of magnitude in bunch charge, emittance, and current, alongside sub-picosecond pulse lengths. This makes injector setup and tuning a significant challenge. With the world's first beam achieved at SEALab from a Na-K-Sb cathode in our SRF gun, a suite of beam dynamics models has been developed to support understanding of the beam behaviours in the gun, where no observations are possible, and operation of the commissioning process. This is comprised of a first-order analytical model, particle-in-cell (PIC) ASTRA simulations, and a machine-learning surrogate model trained for current commissioning operation ranges. These models are coupled with a Multi-Objective Bayesian Optimisation (MOBO) algorithm to enable rapid tuning across multiple beam modes. This combination of surrogate modelling and optimisation algorithm reduces optimisation timescales from hundreds of hours to minutes, allowing near-real-time tuning for the accelerator. This work presents the modelling framework, its validation, and its application to SEALab's many-mode optimisation challenges.
Paper: WEPS043
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-WEPS043
About: Received: 28 May 2025 — Revised: 01 Jun 2025 — Accepted: 01 Jun 2025 — Issue date: 05 Nov 2025
WEPS047
Report on Opera-3D hands-on session in the 7th International School on Beam Dynamics and Accelerator Technology (ISBA24)
2345
The 7th International School on Beam Dynamics and Accelerator Technology (ISBA24) held in Chiangmai University during November 1-9, 2024, encompasses seven days opportunities where the foundation of accelerator physics is applied during hands-on sessions with simulation software including ASTRA, ELEGANT, Opera-3D and CST Studio Suite. Opera-3D, a finite element-based Maxwell’s equations solver, is known for its powerful low frequency simulation capabilities and is appropriate for magnet design. Instructed by two lecturers from Synchrotron Light Research Institute, 15 students from China, Japan, India and Thailand were trained on the Opera-3D software fundamentals in the application of magnet design for particle accelerator. The students showcase their knowledge in the group assignments including the design of H-shape dipole, C-shape dipole and combined horizontal and vertical corrector with success. Thanks to the generous support of the ISBA24 sponsors and Sigma Solutions Co., Ltd., who provided the software licenses during the school. This article reports on the completion of the ISBA24 Opera-3D hands-on session provided to graduate students and young researchers from the Asian region.
Paper: WEPS047
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-WEPS047
About: Received: 18 May 2025 — Revised: 30 May 2025 — Accepted: 31 May 2025 — Issue date: 05 Nov 2025
WEPS048
Design of non-linear kicker for Siam Photon Source II
2348
A non-linear kicker (NLK) is designed for the beam injection into the storage ring of Siam Photon Source II. The required deflection angle is 4 mrad, the effective length is 400 mm and the peak field is 100 mT at the horizontal position of 9 mm from the magnet center. The design is based on 8-wire configuration where the conductor position is symmetric along the xz and yz planes. The vertical size of ceramics chamber is determined by the vertical beam stay-clear at the magnet position, available space for magnet installation and feasibility of conductive coating process. Magnetic field calculation of the NLK is performed in Radia and Opera-3D. The octupole-like magnetic field with the field-free region at the magnet center minimizes perturbation on the stored beam. Nevertheless, position error of the conductors leads to excess dipole and quadrupole field components at the magnet center. Magnetic field distortion is also caused by Eddy current induced in the conductive coating in transient analysis. In this work, magnetic design and magnetic field calculation of the NLK is presented.
Paper: WEPS048
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-WEPS048
About: Received: 28 May 2025 — Revised: 30 May 2025 — Accepted: 30 May 2025 — Issue date: 05 Nov 2025
WEPS049
Development of stretched wire system for magnetic field measurement of magnets for Siam Photon Source II
2351
A stretched wire measurement system was developed for magnetic field measurement of magnet prototype for Siam Photon Source II. It is used for magnetic field integral measurement for characterization of multipole field errors, magnet centering and fiducialization of multipole magnets. The wire trajectory across magnet aperture can be either linear or circular. The maximum wire movement is ±100 mm in both horizontal and vertical directions with the positioning accuracy of ±2 µm. The system is built on a 3.2-m granite support which allows the maximum magnet length of 2.2 m and magnet weight of 2,500 kg to be measured. Effects of wire tension, scan region, pause time between measurements, wire movement speed, number of repeated measurements and number of data points have been studied. With the optimized measurement parameters, the repeatability of 3E-4 or better can be achieved for the normalized multipole components measured using the circular scan.
Paper: WEPS049
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-WEPS049
About: Received: 28 May 2025 — Revised: 30 May 2025 — Accepted: 30 May 2025 — Issue date: 05 Nov 2025
WEPS067
Development of high-power RF components for an X-band transverse deflector system at SACLA
2385
We have been developing an X-band transverse deflector system (XB-TDS) with sub-fs time resolution, which will be installed after the undulator sections at SACLA. A sub-fs XFEL pulse is desirable for user experiments such as the measurements of structural disordering in an XFEL interaction with a matter, as the degree of damage depends on the pulse duration. The demand for a shorter and shorter XFEL pulse is increasing. The SACLA’s XFEL pulse duration is 6 fs at FWHM. In order to achieve a shorter XFEL pulse duration and to satisfy users’ needs, a diagnostic system of the longitudinal bunch distribution is essential. We adopt an X-band frequency to efficiently deflect an 8 GeV electron beam. We feed 20 MW to the pulse compressor, and the peak power is increased to around 100 MW, which is divided into four cavities, generating HEM11 horizontal mode. We utilize a dipole magnet before the beam dump to measure the energy-time distribution.The current status is to manufacture high-power RF components such as deflector cavity, pulse compressor, and dummy load. In this presentation, we will show the design, manufacturing method, and commissioning status of these components.
Paper: WEPS067
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-WEPS067
About: Received: 28 May 2025 — Revised: 02 Jun 2025 — Accepted: 03 Jun 2025 — Issue date: 05 Nov 2025
THYD1
Reinforcement learning in particle accelerators
2481
Reinforcement learning (RL) is a unique learning paradigm inspired by the behaviour of animals and humans to learn to solve tasks autonomously. Learning occurs through interactions with an environment, exploring, and evaluating strategies under various conditions. RL excels in complex environments, can handle delayed consequences, and is able to learn solely from experience without access to an explicit model of the system. This makes RL particularly promising for particle accelerators, where the dynamic conditions of particle beams and accelerator systems require continuous adaptation, and modelling is challenging. Although RL applications are emerging in accelerator physics and showing promising results, their widespread introduction faces critical challenges. Among the main obstacles are the effective formulation of control problems, training, and the deployment of solutions in real systems. This paper provides an overview of the potential of RL in accelerator applications, highlighting current challenges and future research directions.
Paper: THYD1
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-THYD1
About: Received: 27 May 2025 — Revised: 30 May 2025 — Accepted: 05 Jun 2025 — Issue date: 05 Nov 2025
THPB002
Vacuum system of MAX4U – an upgrade of MAX IV 3 GeV storage ring
2503
MAX 4U is an upgrade project of the MAX IV 3 GeV storage ring, to be realized by the early 2030’s in Lund, Sweden. The goal of the upgrade is to reduce the horizontal electron beam emittance to below 100 pm.rad. A new magnet lattice will be used, thus the vacuum system will have to be adapted to follow the new beam orbit of MAX 4U. Several lattices imposing the most severe changes to the beam orbit were studied. One proposal for the MAX 4U vacuum system is to re-use and adapt under vacuum the shape of the MAX IV 3 GeV ring vacuum chambers (coated with non-evaporable getter (NEG) thin film) by bending-to fit to the new magnet lattice. In such scenario, the vacuum system will not be vented, thus the NEG coating will not have to be re-activated. Such approach is very cost-effective and reduces the installation and commissioning time to the minimum. This scenario is presented here, together with the performed simulations, validation studies and tests.
Paper: THPB002
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-THPB002
About: Received: 16 May 2025 — Revised: 13 Oct 2025 — Accepted: 13 Oct 2025 — Issue date: 05 Nov 2025
THPB004
Development of residual gas analyzer measurement system capable of operating in the 10 Torr vacuum range
2507
Residual Gas Analyzers (RGA) are widely used to mon-itor gas composition in vacuum systems. However, they are typically limited to high-vacuum environments and cannot be used directly in processes that operate at higher pressures. To solve this problem, we developed a modular and easy-to-build differential pumping system that allows an RGA to monitor vacuum environments up to 10 Torr. In this study, we present the design of this system. Thanks to its modular design, the system can be easily extended to operate at higher working pressures by adding more modules.
Paper: THPB004
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-THPB004
About: Received: 26 May 2025 — Revised: 02 Jun 2025 — Accepted: 13 Oct 2025 — Issue date: 05 Nov 2025
THPB019
Lifecycles and workflows for 3D integration studies at CERN
2544
The implementation of a new product data management (PDM) and product lifecycle management (PLM) system at CERN has significantly improved lifecycles and workflows for 3D integration studies, thanks to the advanced features and tools of the platform. This new PDM/PLM system has provided an opportunity to reassess and optimize user methodologies, focusing on better organization of 3D CAD data, improved collaboration with mechanical and services design offices, and more effective validation processes. Additionally, enhanced traceability throughout workflows is expected to boost overall process quality. This paper examines the challenges encountered during the transition as well as the benefits of the new PDM/PLM, highlighting its contribution to increased efficiency and quality.
Paper: THPB019
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-THPB019
About: Received: 27 May 2025 — Revised: 13 Oct 2025 — Accepted: 13 Oct 2025 — Issue date: 05 Nov 2025
THPB023
Numerical simulation of a modified air conditioning system of the experimental hall at TPS
2552
Taiwan Photon Source (TPS) has been committed to serve users for eight years. In the first and second phases of TPS beamline project, there were 16 beamlines had been in operation. The third phase project had been launched in 2021. Facing the more persons and equip-ment in the experimental hall as well as power saving issue, we applied the computational fluid dynamic (CFD) scheme to simulate the air conditioning system to obtain better cooling efficiency. We modelled one twelfth of the TPS experimental hall and two beamlines.
Paper: THPB023
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-THPB023
About: Received: 28 May 2025 — Revised: 30 May 2025 — Accepted: 13 Oct 2025 — Issue date: 05 Nov 2025
THPB034
A radiation-resistant distributed temperature sensor for CERN’s accelerators
2583
Optical Fibre Sensors (OFS) possess unique features, such as high sensitivity, versatility, and the ability to operate in harsh radiation environments. Distributed OFS are notable for enabling real-time monitoring over large-scale facilities, making them ideal for applications in particle accelerators. Their distributed measurement capabilities provide comprehensive monitoring while offering a cost-effective alternative to conventional pointwise technologies. As part of the Innovation work package of CERN’s Personnel Safety System Consolidation program, an experimental study was conducted to characterize the performance of a radiation-hard Distributed Temperature Sensor (DTS) to complement CERN’s safety systems, addressing cryogenic leaks and fire risks. Several fire tests were performed to assess the sensor's accuracy and temporal response under emergency-like conditions. A phenomenological model was derived from these tests to predict the system's behaviour in real-world scenarios. The obtained results are key to the first deployment and operation of a dedicated DTS demonstrator in a part of the LHC in 2025.
Paper: THPB034
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-THPB034
About: Received: 26 May 2025 — Revised: 14 Oct 2025 — Accepted: 14 Oct 2025 — Issue date: 05 Nov 2025
THPB050
Development of robust beam window by additive manufacturing
2609
Construction of the COMET experimental facility is underway to explore the muon-electron conversion process at the J-PARC Hadron facility. An 8 GeV proton beam supplied from the main ring irradiates a target in a superconducting capture solenoid magnet, and the produced pions and muons are transported to the experimental area. In the beam line, the muon transport solenoids are composed of superconducting magnets cooled by liquid Helium (LHe). The beam windows should be robust enough to withstand against rapid and high pressure increase in emergency of LHe quenching until rupture disks break. Simultaneously, the density of the beam window material must be low, and the thickness must be as thin as possible, while minimizing the beam energy loss for high transmission efficiency. Therefore, we have been developing a beam window built by additive manufacturing. We have successfully developed a beam window made of Ti-6Al-4V with a diameter of 269 mm, a thickness of 0.5 mm, and a proof pressure of 30 atm, and have now started development of a beam window made of AlSi10Mg. In this presentation, we will report on the development status of the beam window by additive manufacturing.
Paper: THPB050
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-THPB050
About: Received: 28 May 2025 — Revised: 02 Jun 2025 — Accepted: 04 Jun 2025 — Issue date: 05 Nov 2025
THPB079
Investigation of properties of CuZr alloy for vacuum chamber structural materials
2644
CuZr alloy is considered for the structural material of the vacuum chamber of the Hefei Advanced Light Facility (HALF) storage ring. We tested the outgassing rate of CuZr material. The outgassing rate of CuZr alloy can reach 4.93×10^-11 Pa·L/s·cm² after baking at 180°C for 48h, which is more than one order of magnitude lower than that of SS. These results indicate that CuZr alloy is easier to degas by baking at lower temperatures and is a material with very low outgassing rates. At the same time, it is a highly competitive structural material for future accelerator vacuum chamber based on its good electrical conductivity, high strength and hardness.
Paper: THPB079
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-THPB079
About: Received: 17 May 2025 — Revised: 14 Oct 2025 — Accepted: 14 Oct 2025 — Issue date: 05 Nov 2025
THPB090
Accelerator test facility upgrades to enable further advancements in the science and technology of accelerators
2661
The Accelerator Test Facility* (ATF) is the DoE Office of Science User Facility aimed to provide users with a high brightness electron beam, near-infrared (NIR), and long-wave infrared (LWIR) laser beams. The unique capabilities at the ATF include the possibility to combine the electron beam with synchronized high-power laser beams. It is planned to upgrade the facility to have enhanced capabilities. They will include: an increased electron beam energy from the present 65-70 MeV to 110-120 MeV; a reduced by a factor of about 10 phase jitter; and an improved - to femtoseconds’ scale - time synchronization between the electron beam and the laser beams. To accomplish these tasks, the ATF will design and deploy a new High Level RF System, a new Low Level RF System, and a new Time Distribution System. In addition, the ATF will change the Power Plant for the quadrupole and correction magnets to increase operations’ reliability. It is expected that the planning stage will be completed in about 3 years, and the actual hardware deployment will be finished after that in the next 2 years. Different upgrade options are being investigated now and are described in the presented article.
Paper: THPB090
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-THPB090
About: Received: 21 May 2025 — Revised: 03 Jun 2025 — Accepted: 03 Jun 2025 — Issue date: 05 Nov 2025
THPB093
Current status of permanent magnet radiation resiliency studies at CEBAF
2664
One possible future for Jefferson Lab’s Continuous Electron Beam Accelerator Facility (CEBAF) lies in upgrading its maximum nominal energy using Fixed-Field Alternating-gradient (FFA) technology for its recirculating arcs. The current proposal aims to use permanent magnets to supply the fixed fields. One concern among reviewers is the degradation of these permanent magnets during operation due to the radiation environment in which they will be present. This work, funded by a Laboratory Directed R&D grant, aims to measure the magnet degradation in the CEBAF tunnel enclosure, and extrapolate to the energies expected from the upgrade. We present the latest results of this study, as well as plans moving forward.
Paper: THPB093
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-THPB093
About: Received: 27 May 2025 — Revised: 30 May 2025 — Accepted: 31 May 2025 — Issue date: 05 Nov 2025
THPM001
Magnetic field control in the MedAustron synchrotron
2687
MedAustron, a synchrotron-based ion therapy centre in Austria, is focused on enhancing cancer treatment performance. A key improvement opportunity lies in the regulation of the main ring bending dipoles, which currently require time-consuming procedures to ensure reproducibility and reliability of the associated magnetic fields (B-Fields). Other therapy centres globally address this through a traditional B-train or similar systems to regulate on the B-Field and mitigate parasitic effects. In contrast to that, we propose a novel approach utilising a single Hall probe measurement inside a reference magnet, fused with a magnet model to provide real-time, high accuracy estimates of the integral B-Field for regulation. This technique, combined with a tailored controller, is evaluated under typical therapy cycling conditions. The system's performance is demonstrated through metrological analysis and beam property comparisons. Most importantly, the results show the possibility of significant improvements in treatment time reduction. Ultimately, the already achievable beam position accuracy, and spill structure in the treatment rooms, enable the start of commissioning in 2025.
Paper: THPM001
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-THPM001
About: Received: 28 May 2025 — Revised: 03 Jun 2025 — Accepted: 04 Jun 2025 — Issue date: 05 Nov 2025
THPM002
VHEE FLASH radiotherapy: cutting-edge research at CLEAR, the CERN Linear Electron Accelerator for Research
2691
With the current availability of cost-effective and compact electron LINACs operating in the 100-200 MeV energy range, there has been a growing interest in using Very High Energy Electron (VHEE) radiotherapy (RT) for cancer treatment. A particularly intriguing aspect is the Ultra High Dose Rate (UHDR) or FLASH dose regime, which focuses on damaging cancerous cells while sparing healthy tissues. VHEE beams are well-suited for FLASH RT, given their deep penetration and high beam current, making them effective for treating large, deep-seated tumors. The CLEAR (CERN Linear Electron Accelerator for Research) facility has been at the forefront of exploring VHEE and FLASH RT, conducting numerous unique experiments in collaboration with multidisciplinary user groups having experience in dosimetric, chemical, and biological studies. This paper introduces recent measurements, techniques, and methods used to observe the FLASH effect at CLEAR.
Paper: THPM002
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-THPM002
About: Received: 27 May 2025 — Revised: 02 Jun 2025 — Accepted: 03 Jun 2025 — Issue date: 05 Nov 2025
THPM007
Time-varying Bayesian optimisation for continual optimal injection in the CERN PS Booster
2695
The Proton Synchrotron Booster (PSB) receives 160 MeV H- ions, which are converted to protons at injection via a charge exchange mechanism, an upgrade that allows the production of low-loss high-intensity beams (> 10^13 per ring). To mitigate losses due to space charge, horizontal phase-space painting is performed with a system of fours kickers whose pulse is customisable via time and amplitude parameters. Recent work has shown that classical optimisation algorithms can find the optimal parameter values on both a digital twin and the real machine. However, these techniques: do not handle system-state time variations, do not continually update the parameters during operation, require non-negligible dedicated beam time and are usually not robust to observation noise. We suggest time-varying Bayesian optimisation and show that it addresses each of the previous issues at low development and deployment cost. This work improves the operation of the PSB and contributes towards the goal of automating the operation of particle accelerators.
Paper: THPM007
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-THPM007
About: Received: 19 May 2025 — Revised: 02 Jun 2025 — Accepted: 03 Jun 2025 — Issue date: 05 Nov 2025
THPM008
Virtual temperature measurements of ferrite in in-vacuum kicker magnets
2699
The Large Hadron Collider (LHC) Injector Upgrade project has achieved unprecedented beam brightness levels, to fulfill the High Luminosity LHC requirements. This higher intensity has introduced significant challenges for some of the Super Proton Synchrotron (SPS) kickers, specifically concerning beam-induced heating and vacuum rise due to electron cloud. The primary concern is the integrity of the ferrite within the kicker magnets, which is critical to the system's operation and availability. Currently, temperature monitoring relies on temperature probes (PT100) installed on the magnet's frame, but these do not provide direct measurements of ferrite temperature. To address this limitation, we present a method using deep learning techniques to develop a virtual temperature sensor, enabling real-time monitoring of ferrite temperatures across the kicker module. We apply this approach to some of the SPS injection kicker family, the so-called MKP-S, and discuss the general applicability of the method to other systems.
Paper: THPM008
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-THPM008
About: Received: 20 May 2025 — Revised: 02 Jun 2025 — Accepted: 04 Jun 2025 — Issue date: 05 Nov 2025
THPM010
Using machine learning techniques for BGI-based profile measurements at the CERN PS
2707
The Beam Gas Ionization (BGI) instrument provides a non-destructive method for monitoring transverse beam profiles by detecting free electrons produced during beam-gas ionization. Utilizing a Timepix-family detector, the BGI setup at the CERN Proton Synchrotron (PS) includes two instruments dedicated to horizontal and vertical plane measurements. However, the quality of these measurements is often compromised by artifacts, such as beam losses, which degrade profile quality, make the analysis significantly more difficult and ultimately affect the instrument performance. To address these challenges, this contribution explores the application of machine learning techniques for effective background removal. Both supervised and unsupervised approaches are evaluated on data acquired from the operational systems to improve the accuracy and reliability of the reconstructed profiles. Furthermore, the computational performance and time complexity of these methods are evaluated to ensure that the proposed solutions are compatible with the operational requirements of the BGI system.
Paper: THPM010
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-THPM010
About: Received: 28 May 2025 — Revised: 04 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 05 Nov 2025
THPM012
Optimizing collimator positions using bayesian optimization in the Fermilab MI-8 transfer line
2711
Collimators are used to minimize losses and to remove particles that would otherwise get lost downstream and irradiate the machine. Finding the optimal jaw positions is time consuming and with the upstream beam properties changing, the collimation settings would need to be readjusted each time. Therefore, a method to optimize collimator positions and to operate them at full capacity in a short time is required for loss control downstream. A study of collimator positions was conducted and a machine learning (ML) model was developed to predict optimal collimator positions. Bayesian Optimization (BO) was used to calculate new jaw positions from the ML model. The results of BO and usage of ML for better performance of the collimation system are presented in this paper.
Paper: THPM012
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-THPM012
About: Received: 29 May 2025 — Revised: 01 Jun 2025 — Accepted: 01 Jun 2025 — Issue date: 05 Nov 2025
THPM016
Neural networks approach for controlling a waveform pattern of the paint bump power supply at J-PARC RCS
2715
Four horizontal paint bump magnets and two vertical paint bump magnets are used for the painting injection to produce a high intensity beam at J-PARC RCS. These paint bump power supplies are composed of the IGBT chopper units, and so the requirement waveforms can be controlled with high precision less than 1%. By using software that automatically creates input voltage (IV) patterns according to the characteristics of the power supply and direct manual adjustment of IV patterns, the current deviation of the painting pattern (PP) is less than ±0.2%.The adjustment of one PP needs about one hour and several days to adjust a total of 90 patterns with six paint bump magnets. Therefore, a reduction in adjustment time is required. In addition, to mitigate the beam loss caused by beam orbit control to a minimum level, we would like to realize a more precise current deviation. To adjust for these PP, we performed neural networks (NN) approach. By learning the IV patterns and output current patterns as training data, the highly accurate IV patterns were confirmed.The presentation reports on the preliminary training results using NN.
Paper: THPM016
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-THPM016
About: Received: 28 May 2025 — Revised: 14 Oct 2025 — Accepted: 14 Oct 2025 — Issue date: 05 Nov 2025
THPM024
Machine learning-driven longitudinal phase space reconstruction for enhanced beam tuning at LANSCE
2733
The Los Alamos Neutron Science Center (LANSCE) relies on accurate tuning of its Drift Tube Linacs (DTLs) to maintain beam quality and operational efficiency. This work introduces a novel machine-learning-based approach to reconstruct the longitudinal phase space (LPS) at the entrance of DTL Tank 1 using two-dimensional phase scans from Tanks 1 and 2. A Deep Neural Network trained on synthetic datasets generated by GPU-accelerated simulations integrates real-time diagnostic data to infer high-resolution LPS distributions. By solving this inverse problem efficiently, the method improves beam delivery precision while reducing operator intervention. Early results indicate that this approach can enhance LANSCE’s operational capabilities, providing a robust framework for accelerator tuning and diagnostics.
Paper: THPM024
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-THPM024
About: Received: 28 May 2025 — Revised: 03 Jun 2025 — Accepted: 04 Jun 2025 — Issue date: 05 Nov 2025
THPM025
Insertion device correction based on machine learning models at the MAX IV 3 GeV ring
2737
Insertion Devices (ID) in particle accelerators introduce orbit distortions that must be compensated. At MAX IV, this compensation traditionally relies on feed-forward tables which are time-consuming to measure, and sensitive to changes in accelerator settings. This study explores the use of machine learning (ML) to automate the generation of feed-forward tables without requiring extensive measurements. Using archived data from ID gaps, beam position monitors (BPM), and corrector magnets, a neural network-based model was developed to replicate the current ID compensation system. Preliminary results show that the model effectively reproduces the existing compensation behavior and suggests potential for adaptive feed-forward tables that refine themselves with online data. In parallel, alternative ML approaches focused on minimizing beam position errors are being investigated. These efforts aim to improve the maintainability of ID compensation and prepare orbit control for future optical changes and new operational scenarios.
Paper: THPM025
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-THPM025
About: Received: 27 May 2025 — Revised: 30 May 2025 — Accepted: 30 May 2025 — Issue date: 05 Nov 2025
THPM026
Application of Bayesian optimization for the TLS booster extraction
2740
Bayesian optimization is a method for performing global optimization on black-box functions using Gaussian processes and an acquisition function. In accelerator parameter tuning, when the number of adjustable parameters is large, finding the global optimal parameters can be time-consuming and often relies on the operator’s experience. Bayesian optimization is well-suited for such scenarios. In this report, we take the booster extraction of the Taiwan Light Source (TLS) as an example, selecting six key adjustable parameters to optimize the extraction efficiency from the booster ring to the transport line. The preliminary test results and implementation details will be discussed in this paper.
Paper: THPM026
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-THPM026
About: Received: 08 May 2025 — Revised: 14 Oct 2025 — Accepted: 14 Oct 2025 — Issue date: 05 Nov 2025
THPM031
Beam Energy Forecasting using Machine Learning at the CLEAR accelerator
2747
In particle accelerators, accurate and stable beam parameters are crucial for experimental success. Traditional methods for measuring parameters like beam energy often rely on invasive techniques that disrupt experiments. This paper presents a novel, non-invasive machine learning-based approach to predict beam energy using parasitic measurements, enabling real-time estimation without interference. The method employs a predictive model optimized for one-step-ahead forecasting and uses time-series data decomposition to handle complex beam energy dynamics. Recursive prediction strategies allow the model to anticipate future variations autonomously. Preliminary results from experiments at the CLEAR accelerator demonstrate the model’s ability to capture both slow trends and rapid energy shifts, adapting to diverse experimental needs. These findings showcase the potential of machine learning to measure beam energy, offering a real-time, non-destructive alternative to conventional methods. This approach promises significant advancements in accelerator-based applications, especially where destructive techniques are impractical.
Paper: THPM031
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-THPM031
About: Received: 28 May 2025 — Revised: 03 Jun 2025 — Accepted: 06 Jun 2025 — Issue date: 05 Nov 2025
THPM032
Toward autonomous control: reinforcement learning for improving CLEAR accelerator performance
2751
Particle accelerators like CLEAR (CERN Linear Accearator for research) are essential tools in advancing various scientific fields. Automating their operation to ensure stability and reproducibility is crucial for future large-scale projects. This paper explores the first steps toward autonomous control of the CLEAR beamline, focusing initially on beam steering and advancing to complex tasks like quadrupole alignment, vital for operational stability. Reinforcement Learning (RL) agents that adapt in real-time via beam screens measurements were trained and tested. The approach is optimized for sampling efficiency, addressing the high cost and invasiveness of data collection in accelerator environments. The method enables single-shot optimization for real operations, reducing the need for manual intervention. Results show that a few hours of training suffice for effective single-step corrections in the latter part of the CLEAR beamline, inspiring further development by the CLEAR research team.
Paper: THPM032
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-THPM032
About: Received: 28 May 2025 — Revised: 03 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 05 Nov 2025
THPM038
Measurement of the radiation damping time via optical methods
2766
The radiation damping time is a crucial parameter that depends on the overall magnetic structure of the accelerator. Accurate measurement of this damping time can provide insights into the fidelity of the accelerator model by allowing for a comparison with calculated damping time values. In this study, we present a series of measurements of radiation damping times at the VEPP-4M and VEPP-2000 collider at BINP. In order to determine the damping time, we recorded the transverse beam profile using a digital camera. The results includes study of the damping times at revolution frequencies and different energies of the beams.
Paper: THPM038
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-THPM038
About: Received: 28 May 2025 — Revised: 02 Jun 2025 — Accepted: 14 Oct 2025 — Issue date: 05 Nov 2025
THPM039
Fast cyclotron beam probe at UC Davis Crocker Nuclear Laboratory
2770
The UC Davis Crocker Nuclear Laboratory houses a 72-inch multi-species Isochronous Cyclotron built in the 1960’s. For many years, previously unexplained beam dynamics have been indirectly observed at the cyclotron by both internal and external experimenters. Investigating these effects within the cyclotron, at the bunch level, has proven particularly challenging due to the cyclotron's harsh environment of strong magnetic fields, high radiation levels, intense RF interference, and limited space. To address these challenges, a compact segmented beam probe was developed, utilizing a scintillator array target coupled to a SiPM array positioned outside the cyclotron via fiber optic cables. This novel beam probe has enabled precise, high-speed measurements of individual beam bunches, providing data to theoretical models and deepening the understanding of beam dynamics allowing for more precise operation of the cyclotron. These advancements are driving efforts to optimize cyclotron performance for diverse applications, including isotope production, ocular melanoma therapy, and a variety of experimental research.
Paper: THPM039
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-THPM039
About: Received: 28 May 2025 — Revised: 01 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 05 Nov 2025
THPM042
Online analysis of proton and lead ion LHC schottky spectra
2773
The Schottky signals encode various beam and machine parameters, such as betatron tune, chromaticity, momentum deviation and transverse emittance. In this contribution we present the architecture and the performance of the system estimating these parameters in real-time, providing the only non-invasive measurement of chromaticity at the Large Hadron Collider. The obtained results are assessed based on chromaticity drift predictions and the measurements from the independent instruments. The remaining challenges are discussed with the outlook for further development given.
Paper: THPM042
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-THPM042
About: Received: 28 May 2025 — Revised: 31 May 2025 — Accepted: 05 Jun 2025 — Issue date: 05 Nov 2025
THPM044
Selecting 1D projections for 2D tomography reconstruction
2781
Previous works on reconstructing the 4D phase space using tomography require optimal selection of projection views to achieve accurate reconstruction. In 2D reconstruction, the process is straightforward, as an object can be evenly sampled by dividing the angles evenly. However, extending this concept from 2D to 4D is not intuitive. This work demonstrates that quaternions can be used to more effectively describe views in 4D and introduces the Fibonacci Flower algorithm and repulsive force algorithm to evenly space views in 4D space in order to achieve higher reconstruction accuracy.
Paper: THPM044
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-THPM044
About: Received: 28 May 2025 — Revised: 03 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 05 Nov 2025
THPM046
Stand-alone operation of the dual-core cryogenic current comparator for FAIR
2785
The Cryogenic Current Comparator (CCC) is a superconducting device for measurement of low intensity beams with magnetic fields in the range of fT. It uses a Superconducting Quantum Interference Device (SQUID) as an ultrasensitive magnetometer and an elaborated superconducting shield for its protection from external magnetic fields. The system is operated in a helium bath cryostat, which has to fulfill many requirements, such as being non-magnetic, pressure/temperature stable (mK), vibration dampening, UHV fit, bakable, compact and accessible for maintenance and repair. First operation of a CCC as beam current monitor was achieved in the 90s at GSI. The idea has been updated for measurement of slow extracted beams and exotic ions at FAIR, and since 2014 there has been steady optimization by an international collaboration of expert institutes. Looking at noise figures and current resolution as well as practical applicability and costs, a Dual-Core CCC (DCCC) has turned out as best candidate for FAIR. In parallel to detector development the cryostat has been investigated and improved. It has recently achieved stand-alone operation, which is a main requirement for FAIR.
Paper: THPM046
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-THPM046
About: Received: 27 May 2025 — Revised: 14 Oct 2025 — Accepted: 14 Oct 2025 — Issue date: 05 Nov 2025
THPM050
Study of laser-beam arrival time synchronization towards sub-picosecond stability level
2800
In order to achieve laser pulse to electron beam arrival time sub-picosecond stability at the accelerator facilities, a new Low-Level Radio-Frequency system clock generators synchronization architecture is currently under investigation in collaboration between KEK (Japan) and IJClab (France). The system is based on the 10 MHz frequency generator (Stanford Research System), White Rabbit Switch, SkyWorks Si5362 clock generator and IDROGEN boards. This report demonstrates the measurement results of the long-term and short- term synchronization between clock generators. Also, the architecture details are discussed in this report.
Paper: THPM050
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-THPM050
About: Received: 27 May 2025 — Revised: 01 Jun 2025 — Accepted: 03 Jun 2025 — Issue date: 05 Nov 2025
THPM057
A full digital beam position and phase measurement signal processing algorithm based on FPGA designed for linear accelerator
2804
A new digital beam position and phase measurement (BPM) system was designed for the ion-Linac (iLinac) accelerator in the High Intensity heavy ion Accelerator Facility (HIAF). The fundamental and the second harmonic signals are retrieved from the BPM electrodes to simultaneously calculate their respective beam positions and phases. All data acquisition and digital signal processing algorithm routines are performed in a field programmable gate array (FPGA). The position and phase information are obtained by using the in-phase and quadrature (IQ) demodulation method. A practical and straightforward method is used to generate the second harmonic reference signal for processing the second harmonics beam signal. The reconfigurable filters are integrated into the FPGA to allow the measurement of short beam pulse length. The laboratory test results show the achieved phase resolution is better than 0.2$^{\circ}$ and 0.03$^{\circ}$ when the input signal is -60 dBm and -45 dBm respectively. A position resolution better than 30 $\mu$m was achieved for an input power level of approximately -60 dBm, and it can reach 7 $\mu$m with the input power higher than -45 dBm. The entire execution time of the algorithm is accomplished within 3.4 $\mu$s, which provides a sufficient reaction time for the fast beam interlock signal to the machine protection system (MPS). The performance of this newly designed prototype BPM electronics was evaluated with the online proton beam.
Paper: THPM057
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-THPM057
About: Received: 29 May 2025 — Revised: 04 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 05 Nov 2025
THPM061
Cavity beam position monitor signal matching by injection pulse
2814
Cavity beam position monitors (CBPMs) are very high-precision devices that, in recent years, have progressed from experimental equipment to standard linac diagnostics in many prominent facilities, most notably free electron lasers. However, the high sensitivity of these devices comes at the cost of a limited measurement range, even with high dynamic range electronics. Furthermore, CBPMs need to be calibrated in situ, ideally by introducing a known beam offset, which is often impractical in large installations. This paper reports on a method to match CBPM beam signals by injecting synchronized and tightly controlled bursts of radio frequency (RF) oscillations into the sensor cavity and reading back their superposition. The method allows compensation for static beam offsets (with beam) and calibrates CBPMs electronically (no beam required), thus removing some of the operational hurdles. We discuss the first demonstration of this method at the Accelerator Test Facility 2 (ATF2).
Paper: THPM061
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-THPM061
About: Received: 30 May 2025 — Revised: 06 Jun 2025 — Accepted: 06 Jun 2025 — Issue date: 05 Nov 2025
THPM069
Applications of waveform digitizers at the TPS and TLS control systems
2829
The retrieved waveform data include pulse magnet power supply waveforms, fast current transformer waveforms, wall current monitor waveform, RF power waveforms, beam signals, and more. These waveforms are crucial for diagnosing subsystem abnormalities and for long-term observation during routine beam operations. Various types of digitizers, capable of remotely accessing waveforms, have been deployed in the TPS and TLS control systems. To enhance data acquisition capabilities and stability, the waveform digitizers have replaced outdated oscilloscopes that were damaged due to prolonged use. Each type of waveform digitizer is equipped with specific sampling rates and data lengths based on the signal properties and intended applications. High-sampling-rate (10 GSPS) digitizers are applied to capture detailed beam-related signals, while universal-sampling-rate (125/500 MSPS) digitizers are employed to record long-term signal variations in a single acquisition. This paper describes the applications of these digitizers and the development of integrated graphical user interfaces for the TPS and TLS control systems.
Paper: THPM069
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-THPM069
About: Received: 29 May 2025 — Revised: 03 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 05 Nov 2025
THPM073
The Issue with XBPM2 in the TPS Front End
2842
Two sets of blade-type beam position monitors (XBPMs) are installed in the Taiwan Photon Source (TPS) front-end. The upstream XBPM, referred to as XBPM1, has been calibrated and can calculate the photon beam center position. The downstream XBPM, referred to as XBPM2, encountered difficulties during calibration. It was unable to obtain an effective linear range. Adjustments to the blade spacing and alternative calibration methods were explored to address this issue. These details will be discussed in the article.
Paper: THPM073
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-THPM073
About: Received: 23 May 2025 — Revised: 14 Oct 2025 — Accepted: 14 Oct 2025 — Issue date: 05 Nov 2025
THPM075
The efforts on beam stability improvement in TPS
2845
This report discusses various efforts to improve beam stability at the Taiwan Photon Source. The Fast Orbit Feedback (FOFB) system is essential for maintaining beam stability in the light source. Considering the trade-off between FOFB reliability and performance, we optimize the FOFB parameters to achieve better orbit stability in the TPS. Occasional spikes in the Beam Position Monitor (BPM) readings are observed in a few BPM pick-ups and it would degrade the efficiency of the FOFB system. The probability of these spikes occurrence could be related to the different filling patterns and beam currents. A schedule for replacing these BPM buttons will be established. Additionally, the effect of various signal processing schemes on the beam is also examined.
Paper: THPM075
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-THPM075
About: Received: 27 May 2025 — Revised: 14 Oct 2025 — Accepted: 14 Oct 2025 — Issue date: 05 Nov 2025
THPM089
Disentangling sudden beam loss events and fast beam abort system with the RFSoC-BPM at SuperKEKB
2870
In the SuperKEKB/Belle-II experiment, various new physics searches are conducted by colliding 4 GeV positrons and 7 GeV electrons. Future plans aim to significantly increase luminosity, targeting an integrated luminosity 100 times higher than current levels. However, the realization of this goal is challenged by the phenomenon of "Sudden Beam Loss" (SBL), characterized by the abrupt disappearance of the beam within tens of microseconds. As presented at IPAC'24, we developed the RFSoC-BOR (Bunch Oscillation Recorder) system, based on the AMD/Xilinx RF System on Chip (RFSoC). This system enables bunch-by-bunch beam position monitoring and detailed SBL data acquisition. Using the RFSoC-BOR, we analyzed SBL events, identified key contributing factors, and gained insight into strategies for mitigation. Our findings have advanced the understanding of SBL, bringing SuperKEKB closer to higher luminosity operation. Additionally, we are extending the functionality of the RFSoC-BOR to develop a fast beam abort system that improves accelerator component protection. This presentation will cover the role of the RFSoC-BOR in SBL analysis, key insights, and progress on the fast beam abort system.
Paper: THPM089
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-THPM089
About: Received: 27 May 2025 — Revised: 31 May 2025 — Accepted: 01 Jun 2025 — Issue date: 05 Nov 2025
THPM091
Extinction Monitoring of Pulsed Proton Beams Using FPGA-Based Peak Detection
2878
The Mu2e experiment at Fermilab imposes stringent requirements on the elimination of out-of-time beam in its pulsed proton beam - a requirement known as "extinction". We present a method to measure the out-of-time particle rates to calculate the level of extinction in the inter-pulse gaps. The proposed method utilizes an array of quartz Cherenkov radiators and photomultiplier tubes to detect particles scattered from a vacuum chamber in the M4 transfer beamline at Fermilab. The measurement will employ a new μTCA-based FPGA system for data acquisition and signal processing, utilizing real-time peak detection algorithms to count scattered beam particles. By integrating data over many transfers, the time profile of the out-of-time beam will be resolved to fractional levels relative to that of the in-time beam. These results are compared with G4beamline simulations to validate models of beam transport, dynamics, and extinction, providing critical input for optimizing beam delivery to Mu2e.
Paper: THPM091
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-THPM091
About: Received: 28 May 2025 — Revised: 02 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 05 Nov 2025
THPM100
Optimization of Siam Photon Source storage ring using Badger
2898
Badger is optimization software created for the purpose of real-time accelerator tuning and operation. A range of optimization algorithms are available on this platform, implemented with both graphical and command-line user interfaces. This study shows the improvements in beam size, beam lifetime and related parameters at the Siam Photon Source storage ring following the application of Badger. The optimization results will be presented.
Paper: THPM100
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-THPM100
About: Received: 28 May 2025 — Revised: 29 May 2025 — Accepted: 29 May 2025 — Issue date: 05 Nov 2025
THPM102
High efficiency multi-objective Bayesian algorithm for APS-U nonlinear dynamics tuning
2905
The Advanced Photon Source (APS) facility has just completed an upgrade to become one of the world’s brightest storage-ring light sources. Machine learning (ML) methods have seen extensive use during commissioning. One important application was multi-objective tuning of dynamic aperture and lifetime, a complex high-dimensionality task intractable with classic optimization methods. In this work we will discuss novel Bayesian optimization (BO) algorithmic and implementation improvements that enabled this use case. Namely, pre-training and uncertainty-aware simulation priors, dynamic parameter space and acquisition function refinement, and an adaptive wall-time convergence criteria. We will also show results of optimization runs from 10 to 24 dimensions, benchmarking scaling and efficiency as compared to standard MOGA and MGGPO. Given the promising performance, work is proceeding on tighter BO integration into the control room.
Paper: THPM102
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-THPM102
About: Received: 29 May 2025 — Revised: 04 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 05 Nov 2025
THPM106
Multimethod signal processing for comprehensive tune coupling characterization at Canadian Light Source
2909
This study compares Fast Fourier Transform (FFT), Power Spectral Density (PSD), and Wavelet Analysis for detecting tune coupling at the Canadian Light Source (CLS). Data were analyzed for low coupling, 1.4%, and 2.5% high coupling regimes, focusing on frequency identification and amplitude stability in X and Y directions. FFT revealed ~15% amplitude fluctuations, complicating tune identification. PSD provided better stability, with only 4% amplitude variations. Both methods were computationally efficient, with FFT taking, 0.0103 seconds and PSD, 0.0108 seconds per calculation. Wavelet analysis preserved temporal-frequency relationships, revealing delays between X and Y frequencies of 2.38 to 4.77 microseconds in the 1.4% regime and peak periods around 18 microseconds. In high coupling, X frequencies preceded Y frequencies, with dominant frequencies showing higher amplitudes than perturbed ones. These findings demonstrate PSD's stability for tune measurements and Wavelet Analysis's ability to capture temporal dynamics, providing insights to enhance beam stability in accelerator systems.
Paper: THPM106
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-THPM106
About: Received: 23 May 2025 — Revised: 02 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 05 Nov 2025
THPM110
Machine learning for the anomaly detection and characterization of the 24 GeV/c proton beam at CERN IRRAD Facility
2917
The accurate assessment of beam quality is the most important aspect in the irradiation facilities operation such as IRRAD at CERN. The Beam Profile Monitor (BPM) sensor system developed for the high-intensity proton beam at IRRAD features minimal particle interaction, improved radiation hardness and higher sensitivity and sampling rate than previous systems. It provides a wealth of high-quality BPM data not available earlier, enabling the development of data processing more advanced than before. To take advantage already today of this upgraded BPM system’s features, we propose innovative Machine Learning (ML) techniques to adapt and improve upon existing DAQ technology. This paper details the application study of (1) autoencoder architectures to perform the automatic pattern recognition and anomaly detection of proton beam profiles, and (2) deep learning techniques to predict relevant beam parameters. We applied this approach to a new dataset (made publicly available) of BPM data taken during the recent runs of IRRAD; our preliminary results demonstrate good performance in comparison to existing methods. This work is a first step towards the "intelligent" irradiation facilities.
Paper: THPM110
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-THPM110
About: Received: 28 May 2025 — Revised: 03 Jun 2025 — Accepted: 03 Jun 2025 — Issue date: 05 Nov 2025
THPM112
Detecting anomalies in non-static environments: continual learning applied to CERN's kicker magnet
2924
The CERN accelerator complex relies critically on fast injection and extraction processes to transfer particle beams between accelerators via fast pulsed magnets, or kickers. Ensuring high availability is paramount, as the reliability of these systems directly impacts the large number of experiments conducted at CERN. In this paper, we propose to explore Continual Learning (CL) methods, specifically using Variational Autoencoders (VAEs), to develop an anomaly detection system for the fast kicker magnets. By continuously learning from evolving data while retaining prior knowledge, these models will be capable of detecting anomalies without the need for repeated retraining. This approach is particularly relevant for ensuring the reliability and stability of kicker magnets, where early anomaly detection is critical for preventing performance degradation.
Paper: THPM112
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-THPM112
About: Received: 27 May 2025 — Revised: 04 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 05 Nov 2025
THPM113
Trajectory steering for DC beams at the CERN SPS using reinforcement learning based on intensity measurements
2928
The slow extracted beams at the CERN Super Proton Synchrotron (SPS) are transported over several 100 m long transfer lines to three targets in the CERN North Area Experimental Hall. The experiments need intensity fluctuations to be entirely eliminated over the roughly 5 s particle spill, requiring full debunching of the extracted beams. In this environment, secondary emission monitors (SEMs) have to replace the conventional beam position monitoring systems that rely on RF structure, with the intensity difference on split secondary emission foils used to indicate the beam position. Traditional trajectory correction algorithms however fail when the beam ends up on a single foil. This paper summarises successful first tests with reinforcement learning (RL) to learn to correct the trajectory based on foil intensity measurements. The RL agents were trained in simulation and then successfully transferred to the real accelerator environment. Results of the application of the trained RL agents for the alignment of moveable split foils in front of the targets will also be presented.
Paper: THPM113
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-THPM113
About: Received: 26 May 2025 — Revised: 02 Jun 2025 — Accepted: 04 Jun 2025 — Issue date: 05 Nov 2025
THPS005
Status and event automatic notification development with mobile system at NSRRC
2946
The National Synchrotron Radiation Research Center (NSRRC) is dedicated to enhancing the operational efficiency of its facilities and improving user experience by developing a status and event automatic notification system. This system aims to monitor equipment status in real-time and automatically notify relevant personnel in case of anomalies or significant events. It continuously monitors and inspects the operational status of synchrotron radiation facilities, ensuring all equipment operates at optimal conditions. Notifications of abnormal statuses and events will be automatically sent to relevant technical and management personnel. The benefits include increased operational efficiency, enhanced safety, and optimized resource management. These development efforts will be presented in this report.
Paper: THPS005
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-THPS005
About: Received: 03 Jun 2025 — Revised: 14 Oct 2025 — Accepted: 14 Oct 2025 — Issue date: 05 Nov 2025
THPS006
Applications of SNMP and syslog monitoring at the TPS control system
2949
The TPS (Taiwan Photon Source) control system is a critical component of the accelerator and beamline. Since the TPS control system is based on the EPICS framework, which communicates through a network, any failure in the control network may result in communication loss between EPICS IOCs, ultimately affecting accelerator operation. To ensure stability, it is necessary to monitor the network status of the control system. This is achieved by using SNMP and SYSLOG to monitor network con-nected devices. This report describes the system architec-ture and implementation details, focusing on how to integrate these technologies to ensure the stable opera-tion of the TPS accelerator control system.
Paper: THPS006
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-THPS006
About: Received: 28 May 2025 — Revised: 14 Oct 2025 — Accepted: 14 Oct 2025 — Issue date: 05 Nov 2025
THPS009
The observer-based estimation of photon beam position for improved beamline stability at SPS
2960
This paper presents the development and implementation of an observer-based estimation method to determine the photon beam position for various beamlines at the Siam Photon Source (SPS). The research, executed over multiple phases, aims to address position drift issues in photon beamlines, particularly those without installed photon Beam Position Monitoring Systems (pBPMs). The method allows real-time estimation of beam positions, which are then used as inputs for the SPS’s central control system to enhance beam stability. This observer-based approach provides a cost-effective solution by eliminating the need for additional pBPMs installation in space-constrained beamlines while maintaining an error margin of less than 10% between estimated and measured positions. This innovation is essential for enhancing the operational stability of existing beamlines and offers a scalable model for similar applications in the future.
Paper: THPS009
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-THPS009
About: Received: 21 May 2025 — Revised: 31 May 2025 — Accepted: 14 Oct 2025 — Issue date: 05 Nov 2025
THPS010
On-line estimation approach to fault-tolerant control of orbit stability at Siam Photon Source
2964
A novel approach combining online unknown input estimation with reconfigurable control has been developed to enhance orbit stability in the Siam Photon Source (SPS) storage ring. These unknown inputs, representing disturbances or uncertainties in the dynamic system, provide valuable insights for achieving robust control. Disturbances such as noise, temperature changes, and modeling uncertainties affecting the control variables can be treated as fault signals, allowing the application of fault estimation and compensation techniques from Fault Diagnosis (FD) and Fault-Tolerant Control (FTC) theories. The initial implementation of this slow orbit feedback (SOFB) system has significantly reduced X-Y orbit fluctuations while maintaining robust control stability against temperature disturbances in the SPS storage ring. This presentation will cover the FD/FTC principles, hardware, software, commissioning results of the current SOFB system, and plans for future developments.
Paper: THPS010
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-THPS010
About: Received: 21 May 2025 — Revised: 14 Oct 2025 — Accepted: 14 Oct 2025 — Issue date: 05 Nov 2025
THPS017
Design and validation of a micrometric and adaptable calibration bench for frequency scanning interferometry sensors
2988
The High-Luminosity Large Hadron Collider (HL-LHC) project at CERN aims to enhance the LHC's performance and increase its discovery potential. As part of this upgrade, new components will be installed and must be aligned with an accuracy of 0.17 mm vertically and 0.33 mm radially (1σ) over a length of 420 m. To achieve such requirements in harsh conditions, CERN has developed a range of new sensors using Fourier analysis-based Frequency Scanning Interferometry (FSI), capable of absolute distance measurements on multiple targets within a few micrometers’ uncertainty. More than 600 of these FSI sensors will be deployed for the project, necessitating an accurate, fast, adaptative and cost-effective calibration of these sensors. To do so, a specialized calibration bench has been developed. This paper details the design, benchmarking, and final validation of this calibration bench, which enables rapid calibration of a wide range of FSI sensors to an accuracy below 10 μm (1σ). Additionally, it presents the first intense use of this bench in the frame of the Inner Triplet String test, a facility representing one complete section of new focusing regions of the HL-LHC upgrade project.
Paper: THPS017
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-THPS017
About: Received: 23 May 2025 — Revised: 05 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 05 Nov 2025
THPS018
A novel calibration method for the High Luminosity LHC wire positioning system sensors
2992
The High Luminosity-Large Hadron Collider (HL-LHC) is an ambitious project aiming to upgrade the LHC to achieve substantially more collisions to increase its potential for new discoveries after 2030. As part of this upgrade, 220 m of new components will be installed on both sides of the interaction points of the ATLAS and CMS experiments. The upgrade includes the installation of over 300 Wire Positioning System (WPS) sensors. Each sensor must be calibrated individually on-site, requiring a fast, accurate, portable and user-friendly calibration bench. This paper introduces a new mobile calibration bench capable of performing both relative and absolute calibrations simultaneously and to determine the absolute polynomial coefficients unique to each sensor. It details the underlying mathematical framework, preliminary test results, and highlights the advantages over the previous generation of test benches. The paper also presents the return of experience gained from the first field tests.
Paper: THPS018
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-THPS018
About: Received: 27 May 2025 — Revised: 14 Oct 2025 — Accepted: 14 Oct 2025 — Issue date: 05 Nov 2025
THPS021
Application of distributed temperature sensor for fire and cryogenic leak detection in accelerator tunnels
2996
High-energy accelerators like CERN’s Large Hadron Collider (LHC) present hazards characterized by temperature variations such as cryogenic leak or fire. Considering that LHC tunnels are large, underground, and radioactive areas, alternatives to traditional systems are explored to improve hazard detection. CERN is investigating the feasibility of installing a large-scale temperature monitoring system in LHC tunnels using Distributed Temperature Sensor (DTS) technology. Based on optical fibre, such a system would be resistant to the LHC radioactive environment and could detect temperature anomalies associated with both fire and cryogenic leak events. This paper presents ongoing studies and a prototype of DTS equipment in the LHC tunnel installed and tested at the beginning of 2025. This publication evaluates the DTS as a safety enhancement tool for accelerator facilities. The potential improvements brought by installing a DTS in LHC tunnels will also be discussed.
Paper: THPS021
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-THPS021
About: Received: 19 May 2025 — Revised: 31 May 2025 — Accepted: 01 Jun 2025 — Issue date: 05 Nov 2025
THPS027
Availability assurance in the future circular electron-positron collider (FCC-ee)
3018
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 long, it is ambitious in size, complexity and technical objectives. Availability is a main challenge. This paper presents results from a Monte Carlo simulation that extrapolates reliability and maintain-ability from systems in current working accelerators to the FCC-ee. Significant integrated luminosity shortfall appears in all energy modes due to low availability and operational efficiency. The primary contributors are highlighted, exposing several compelling R&D opportunities.
Paper: THPS027
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-THPS027
About: Received: 26 May 2025 — Revised: 30 May 2025 — Accepted: 31 May 2025 — Issue date: 05 Nov 2025
THPS030
Auxiliary tools for TPS operation
3030
This article provides an overview of various software tools developed by operators to enhance TPS operations. The primary functionalities of these tools include real-time monitoring and notification of light source statuses, as well as data analysis. The tools covered include the TPS alarm system, LINE notification system, real-time orbit deviation display, real-time fast corrector output display, pulse magnet waveform recording and analysis, parameter value changelog, and tools for comparing power supply readings, eBPMs, ID gaps, and XBPM differences between different time points. Each of these tools will be explained in detail throughout the article.
Paper: THPS030
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-THPS030
About: Received: 20 May 2025 — Revised: 30 May 2025 — Accepted: 14 Oct 2025 — Issue date: 05 Nov 2025
THPS032
Electromagnetic compatibility and spurious triggering detection validation of the CLIQ units for superconducting magnet protection in the High-Luminosity LHC project
3033
The Coupling-Loss-Induced-Quench (CLIQ) concept is an integral part of the quench protection system for the High-Luminosity Large Hadron Collider (HL-LHC) Inner Triplet superconducting magnets at CERN. Since the discharge of the CLIQ unit induces a change of the magnetic field in the low beta quadrupoles, a spurious trigger during operation could deflect the beam, potentially causing critical losses and posing a failure risk for the LHC. To ensure reliable and faultless operation and to prove that the units are immune to potential interferences capable of provoking an erratic trigger, several qualification tests were performed, including interference tests with actual LHC equipment and standard Electromagnetic Compatibility (EMC) tests. Furthermore, the precision of the CLIQ monitoring sensors was validated to confirm that, in the unlikely event of a spurious trigger, the particle beam could be dumped in time to prevent damage. The final CLIQ units, with enhanced redundancy, monitoring and safety measures, and robust EMC design, have been completed. This paper details the conducted EMC tests, confirming their resistance to erratic triggers and ability to timely request beam dumps.
Paper: THPS032
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-THPS032
About: Received: 26 May 2025 — Revised: 31 May 2025 — Accepted: 04 Jun 2025 — Issue date: 05 Nov 2025
THPS033
Upgrade of beam abort system at the SuperKEKB positron ring
3037
We upgraded the beam abort system at the SuperKEKB positron ring to speed up the abort response and mitigate the damage caused by Sudden Beam Loss (SBL). An SBL event can result in the loss of tens of percent of the beam current within one or two turns. The huge radiation accompanying the beam loss can severely damage accelerator hardware and the detectors at the interaction point. The fast-response abort sensors based on the plastic scintillator and SiPM were installed to detect the beam loss from SBL earlier. Besides, the configuration of the abort trigger system (interlock) network was customized to shorten its response. The upgrade work was conducted in the 2022-2024 long shutdown and the 2024 summer shutdown. It was implemented in the beam operation in 2024. After this upgrade, we could throw abnormal beams more than one turn earlier. It is a significant treatment against SBL. We report the details of the upgrade and the improved performance achieved in the 2024 operation.
Paper: THPS033
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-THPS033
About: Received: 30 May 2025 — Revised: 05 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 05 Nov 2025
THPS034
Motion protection framework for TPS insertion device control
3040
The Taiwan Photon Source (TPS) is an advanced synchrotron radiation light source that provides high-brightness light for scientific research and industrial applications. The insertion device (ID) plays a critical role in controlling the electron beam trajectory to enhance synchrotron radiation intensity. However, due to radiation and signal interference in the operational environment, the motion control system of the ID faces challenges, especially when optical encoder anomalies occur, which can affect performance and may, under certain circumstances, lead to hardware damage. Traditional motion protection relies on software soft limits and hardware limit switches, but these mechanisms may not provide comprehensive and effective protection in the event of optical encoder failures. To address this, this paper proposes a multi-layered motion protection system. In addition to incorporating traditional protections, it also introduces an abnormality prediction mechanism based on the difference in optical encoder and potentiometer data. This mechanism can trigger an abort signal to the motor controller when an anomaly is detected to stop the abnormal motion. This architecture significantly improves the operational reliability of the TPS ID, ensuring long-term safe and stable performance.
Paper: THPS034
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-THPS034
About: Received: 26 May 2025 — Revised: 02 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 05 Nov 2025
THPS038
Study on a novel laser fast abort system for SuperKEKB
3048
To ensure stable and continuous commissioning of SuperKEKB, the machine protection system (MPS) plays a crucial role in safeguarding the accelerator's hardware from damage caused by beam loss. The response time of the MPS is a critical factor in mitigating hardware damage caused by the radiation of abnormal beams. In this study, we investigate a novel laser fast abort system for the SuperKEKB accelerator to reduce the response time of the beam abort trigger. The laser, serving as the trigger signal, is transmitted through free space. Compared to the traditional method, the transmission speed is 1.5 times faster than that in optical fiber. This faster signal transmission can shorten the abort time, enabling the realization of effective MPS. The optical design for long-distance laser beam propagation and measurement of coupled laser power have been studied. Investigation will be conducted regarding the long-term stability of the laser beam inside the accelerator tunnel.
Paper: THPS038
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-THPS038
About: Received: 27 May 2025 — Revised: 31 May 2025 — Accepted: 04 Jun 2025 — Issue date: 05 Nov 2025
THPS040
Optimization of Piezo Operation for superconducting TESLA cavities at EuXFEL
3051
Superconducting cavities with high Q-factor require precise tuning to match the RF frequency, ensuring stable electromagnetic fields and minimizing RF power consumption. At the XFEL accelerator, TESLA cavities are tuned using slow tuners (step motors) for coarse adjustments and fast tuners (piezoelectric actuators) for fine-tuning and compensating disturbances such as Lorentz Force Detuning (LFD) and microphonics*. Critical to this system, Piezo actuators require high-voltage (up to 100V) and high-current (up to 1A) driving signals for effective LFD compensation. However, they are vulnerable to overvoltage, overcurrent, and overheating**, and their protection is crucial since replacing damaged piezo in fully assembled modules is unfeasible. Additionally, piezo induced vibrations can affect the machine's stability. Optimizing piezo excitation—by reducing voltage, current, and current slope while ensuring effective LFD compensation—improves both reliability and machine stability. This paper explores the optimization of piezo excitation at XFEL, detailing methods and results applicable to other facilities with superconducting cavities.
Paper: THPS040
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-THPS040
About: Received: 28 May 2025 — Revised: 30 May 2025 — Accepted: 03 Jun 2025 — Issue date: 05 Nov 2025
THPS044
Performances of new frequency sources for TRIUMF ISAC accelerator chains
3061
The TRIUMF ISAC-1 and ISAC-2 accelerator chains uses multiple fixed frequencies in their RF cavities. These include 5.8933 MHz, 11.7866 MHz, 35.36 MHz, 106.08 MHz and 141.44 MHz. These need to be synchronized in phase with respect to each other’s. The new frequency sources use x2, x3 and x4 low phase noise multipliers to generate these frequencies from a single low phase noise 5.8933 MHz frequency synthesizer. Bench tests have shown that the frequency multipliers do not generate additional phase noises, except those that are theoretically produced due to frequency multiplication. With an average performance frequency source as a reference which has -85dBc/Hz at 10 Hz offset, the integrated rms phase noise of 141.44 MHz multiplied output is less than 0.5°.
Paper: THPS044
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-THPS044
About: Received: 24 May 2025 — Revised: 30 May 2025 — Accepted: 01 Jun 2025 — Issue date: 05 Nov 2025
THPS048
eLog analysis for accelerators: status and future outlook
3076
This work demonstrates electronic logbook (eLog) systems leveraging modern AI-driven information retrieval capabilities at the accelerator facilities of Fermilab, Jefferson Lab, Lawrence Berkeley National Laboratory (LBNL), SLAC National Accelerator Laboratory. We evaluate contemporary tools and methodologies for information retrieval with Retrieval Augmented Generation (RAGs), focusing on operational insights and integration with existing accelerator control systems. The study addresses challenges and proposes solutions for state-of-the-art eLog analysis through practical implementations, demonstrating applications and limitations. We present a framework for enhancing accelerator facility operations through improved information accessibility and knowledge management, which could potentially lead to more efficient operations.
Paper: THPS048
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-THPS048
About: Received: 10 Jun 2025 — Revised: 14 Jun 2025 — Accepted: 14 Jun 2025 — Issue date: 05 Nov 2025
THPS059
Comparison of various outgassing rate measurements for UHV systems
3098
Outgassing rate is one of the most important criteria for vacuum acceptance of various components used in ultra-high vacuum (UHV) systems. There are numerous methods to measure the outgassing rate of UHV components. One of the most common techniques is the so called ‘pressure-rise’ method. In this method the component under test is enclosed in a system and disconnected from the pump. The outgassing rate is calculated from the pressure rise that occurs due to the outgassing of the component. Comparing this with other techniques, the pressure-rise method is more straightforward and allows easier analysis of the data. Nevertheless, the outgassing rate obtained from the pressure-rise method tends to be much lower than the actual outgassing rate. This paper presents an investigation of another approach to analysing the data obtained from the pressure-rise method. The objective of this approach is to provide a greater accuracy in the outgassing rate measurement, as well as to understand the reason behind the large error obtained using the pressure-rise method. The new approach of calculating the outgassing rate from the ‘pressure-rise’ method is then compared to other methods.
Paper: THPS059
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-THPS059
About: Received: 19 May 2025 — Revised: 30 May 2025 — Accepted: 30 May 2025 — Issue date: 05 Nov 2025
THPS071
Analysis of noise spectra color on machine learning denoising algorithms
3112
Previous work has shown the efficacy of using machine learning for removal of noise in LLRF signals when operating in an industrial environment. Here we extend the analysis to include different noise power spectra. Specifically we analyze the impact on denoisig when correlated noise power spectra are used. Four different noise spectra are analyzed including red, pink, violet, and blue noise. We demonstrate the ability to remove the noise when trained on only white noise and compare this to results when retraining on different color spectra.
Paper: THPS071
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-THPS071
About: Received: 28 May 2025 — Revised: 05 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 05 Nov 2025
THPS073
Developing an Object Detector Using Synthetic Data from CAD Models
3117
This work investigates the potential of using synthetic images generated from CAD models to train an object detector for identifying components of a particle accelerator. The study focuses on magnets within the new ALS Accumulator Ring at Lawrence Berkeley National Laboratory. Generating large volumes of real-world training data is often challenging in such complex systems. To address this, CAD files were converted into 3D models and used to produce diverse synthetic datasets. These datasets were augmented with a smaller set of real-world images to train a YOLOv8-based model. This approach aims to evaluate whether synthetic images can effectively support the development of object detectors in environments where real data collection is limited. The study lays the groundwork for future development of real-time recognition tools to assist accelerator operations.
Paper: THPS073
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-THPS073
About: Received: 28 May 2025 — Revised: 05 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 05 Nov 2025
THPS089
Measurements for beam size blowup in sudden beam loss events and analysis of the beam loss evolution mechanism
3144
The SuperKEKB electron-positron collider, which aims to achieve the world's highest luminosity, has suffered from "Sudden Beam Loss events (SBL)," in which several tens of percent of the beam current is lost and aborted within a few turns (20-30 µs). We have developed a new turn-by-turn beam size monitor to elucidate the cause and time evolution mechanism of the SBL events from a beam size variation point of view. The beam size monitor has two features: 1) it can measure the beam size variation over dozens of turns just before an SBL-induced beam aborts, and 2) it can measure independently in two different wavelength regions, X-ray and visible light, to ensure redundancy. In the SuperKEKB operation in 2024, we found that the vertical beam size blew up rapidly before a few turns of the abort, up to about ten times larger than the usual beam size. We also found that the size blowup started earlier than the beam position oscillation. In this presentation, we will discuss the mechanism of the beam size monitor we have developed, the analysis results of the measured beam size blowup, and finally, the possible cause and time evolution mechanism of the SBL events.
Paper: THPS089
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-THPS089
About: Received: 28 May 2025 — Revised: 03 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 05 Nov 2025
THPS094
Characterisation of the foreseen turn-by-turn beam position instrumentation for the cSTART storage ring
3154
The KIT cSTART project (compact storage ring for accelerator research and technology) aims to demonstrate injection and storage of a high intensity ultra-short bunch using the FLUTE LINAC, as well as a laser-plasma accelerator (LPA). cSTART is planned to operate with a wide range of demanding parameters, such as bunch charge, bunch length and energy spread (from the LPA), making it extremely challenging for the choice of beam diagnostics with large dynamic ranges that are capable of operating within specifications. Moreover, turn by turn measurements are necessary in the cSTART storage ring as bunch characteristics are expected to dramatically change within a single turn. In this paper, we will describe the planned beam diagnostics system of the cSTART storage ring focusing on the turn-by-turn signal processing and reporting on characterization tests which were performed.
Paper: THPS094
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-THPS094
About: Received: 28 May 2025 — Revised: 03 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 05 Nov 2025
THPS095
New all-digital camera setup at the Karlsruhe Research Accelerator
3158
Until recently, the Karlsruhe Research Accelerator (KARA) located at the Karlsruhe Institute of Technology (KIT) was using analog cameras to monitor fluorescence screens. By now all cameras have been replaced by digital cameras directly connected via ethernet, making it possible to directly integrate them into our EPICS-based control system. The new control system integration also provides for a better continuous statistical analysis and comparison of camera pictures. This paper presents an overview of the new setup, including the post-processing integration making use of Python.
Paper: THPS095
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-THPS095
About: Received: 28 May 2025 — Revised: 31 May 2025 — Accepted: 05 Jun 2025 — Issue date: 05 Nov 2025
THPS098
Enabling arbitrary correlations in beam phase space via curve matching
3166
Beam manipulations require precise control of phase space correlations. Gwanghui's previous work introduced a method for generating arbitrary correlations using Fourier series and cosine sums with transverse wigglers. However, accurately controlling the wigglers to match a desired correlation curve remains challenging, as it involves optimizing parameters like amplitude, phase, and period. Existing optimization methods are computationally intensive and prone to local minima. We address these limitations with a deterministic gradient-based optimization process. Using a differentiable error function, we efficiently perform gradient backpropagation to identify optimal parameters. To minimize the number of wigglers while maintaining accuracy, we adopt a recursive strategy: starting with a single wiggler and iteratively adding one at a time, using results from prior steps as seeds. This approach accelerates optimization and reduces computational demands. Building on this method, we design a feedback control strategy for real-time correlation generation with transverse wigglers, enabling precise, flexible beam manipulation and new possibilities in accelerator physics.
Paper: THPS098
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-THPS098
About: Received: 28 May 2025 — Revised: 04 Jun 2025 — Accepted: 04 Jun 2025 — Issue date: 05 Nov 2025
THPS105
Development of CT monitor to measure the stacking beam current in the FETS-FFA test ring
3177
The FETS-FFA will be a proof-of-principle Fixed Field Alternating gradient accelerator (FFA), to demonstrate the feasibility of these machines to drive megawatt-class spallation neutron sources, such as the proposed ISIS-II. It will accelerate protons from 3 to 12 MeV, and demonstrate high-intensity operation through large space charge tune shift. Beam stacking takes advantage of the static magnetic fields and large momentum acceptance of an FFA, to overcome space-charge intensity limitations by combining beams at their highest energy. Four coasting beams are expected to be stacked over 80 ms, which demands an intensity monitor sensitive to coasting beams over this time. Conventional DC Current Transformer's (DCCT's) have proven difficult to develop for a large aperture, so a single inductive core equipped with a Negative Impedance Converter (NIC) amplifier is being developed to provide a time constant of 1 second. This paper will present a feasibility study of this Current Transformer(CT), as well as bench measurements with a large-aperture FT3M FINEMET core and prototype NIC.
Paper: THPS105
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-THPS105
About: Received: 26 May 2025 — Revised: 02 Jun 2025 — Accepted: 03 Jun 2025 — Issue date: 05 Nov 2025
THPS107
Substrate material studies for PCB-based electro-optical bunch arrival-time monitors for XFELs
3181
The all-optical synchronization system used in many X-ray free-electron laser facilities (XFELs) relies on electro-optical bunch arrival-time monitors (EO-BAM) for measuring the single bunch arrival time with regards to an optical reference. An upgrade of the established EO-BAM is intended to achieve a sensitivity that enables stable operation with bunches down to charges of 1 pC, or to significantly increase the resolution in normal operation. Therefore, the pickup structure, the RF path and the electro-optical modulators are undergoing a fundamental redesign. The novel concept of the pickup structure comprises planar pickups on a printed circuit board (PCB) with integrated combination network and a bandwidth of up to 100 GHz. The theoretical jitter charge product of the preliminary concept has been estimated to be in the order of 9 fs pC and the concept was proven experimentally with a 67-GHz demonstrator at ELBE. In this contribution, we compare ceramic and glass substrates in terms of radiation hardness, sensitivity, and manufacturing capabilities. The achievable bandwidth and sensitivity are influenced by material losses and varying tolerances due to different fabrication methods.
Paper: THPS107
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-THPS107
About: Received: 28 May 2025 — Revised: 31 May 2025 — Accepted: 03 Jun 2025 — Issue date: 05 Nov 2025
THPS108
Measurements of dark current and breakdown phenomena using Faraday cups at the Xband Laboratory for Accelerators and Beams (XLAB)
3185
Two CLIC TD24 accelerating structures, manufactured by CERN, are being tested on the high gradient 12 GHz RF test stand at XLAB. Installed at the end of 2024, these are the first devices to be tested at XLAB. Testing aims to verify that following conditioning they can be reliably operated at accelerating gradients of 100 MV/m. The conditioning process involves slowly increasing the peak RF power and pulse length input to the structure. The peak accelerating gradient at which a structure can operate reliably is limited by electrical breakdown. As conditioning progresses the likelihood a that a breakdown will occur decreases. When a breakdown occurs significant charge is emitted by the structure. Considerable progress has been made in the development of the theory of breakdown formation and the underlying interaction mechanisms. Accurate measurements of breakdown phenomena are required to test these understandings. Faraday cups installed upstream and downstream of the structures and connected to high resolution digitisers are employed to measure the behaviour of the breakdown current emissions and dark current. The results of these measurements are presented here.
Paper: THPS108
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-THPS108
About: Received: 28 May 2025 — Revised: 04 Jun 2025 — Accepted: 04 Jun 2025 — Issue date: 05 Nov 2025
THPS109
Non-destructive measurements of non-relativistic ion beam bunch shapes at RAON
3189
Characterizing the longitudinal bunch profile is crucial for understanding beam dynamics and ensuring optimal accelerator performance. To address these needs, Capacitive Pick-Up type Bunch Shape Monitors (CPU-BSMs) were developed at the Institute for Rare Isotope Science (IRIS). These devices non-destructively measure the longitudinal bunch shapes of non-relativistic, nanosecond-scale ion beam bunches. Initial feasibility tests were conducted at a 30 MeV cyclotron to verify the performance of the CPU-BSMs. Subsequently, in 2024, the CPU-BSMs were employed during Nuclear Data Production System (NPDS) beam commissioning at the Rare Isotope Accelerator complex for ON-line experiments (RAON) to characterize both the longitudinal bunch shapes and the beam energy values. In this presentation, we will report the experimental results obtained using the CPU-BSMs during the NPDS beam commissioning at RAON.
Paper: THPS109
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-THPS109
About: Received: 06 Jun 2025 — Revised: 14 Jun 2025 — Accepted: 14 Jun 2025 — Issue date: 05 Nov 2025
THPS113
Automated control and monitoring system for the Crocker Nuclear Laboratory cyclotron
3197
The Crocker Nuclear Laboratory at UC Davis operates a 72-inch isochronous cyclotron capable of accelerating protons, deuterons, and alpha particles to variable energies up to a maximum of 67.5 MeV for protons. The cyclotron is primarily used for proton therapy, conducting radiation effects testing, and supporting academic research. We describe the upgrade of its original analog control system to a modern digital system capable of integrating AI-based control. This upgrade involves new hardware and software infrastructure to manage subsystems such as the ion beam source, isochronous magnetic field, beam extraction, and beam transport lines. The integrated monitoring and actuator systems are currently being implemented and validated, featuring real-time visualization, a database, and a web application. The new system aims to enhance operations through improved data visualization, database accessibility, and the implementation of autonomous AI-based control, incorporating techniques like artificial neural networks for anomaly detection and automated tuning for efficiency. This document details the hardware and software architecture of the PLC-LabVIEW-Python AI-based control system.
Paper: THPS113
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-THPS113
About: Received: 28 May 2025 — Revised: 04 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 05 Nov 2025
THPS134
Enhancing quench detection in SRF cavities at the EuXFEL: Towards machine learning approaches and practical challenges
3226
Detecting anomalies in superconducting cavities at the EuXFEL is essential for reliable operation. We began with a model-based anomaly detection approach focused on residual analysis. To improve fault discrimination, particularly for quench events, we augmented the detection with a machine learning-based classification. Key challenges are posed by the transition to real-time operation, requiring computational and integration adjustments. For the online application, we deployed two servers at one of the 25 stations to detect and log anomalies with a software implementation. In parallel, we pushed the development of a firmware solution that will counteract critical faults in real-time. At the current stage only the anomaly detection is in online operation, which is planned to be augmented with the online fault classification in the future. The resulting detection system delivers reports across various timescales, supporting both immediate responses and long-term maintenance.
Paper: THPS134
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-THPS134
About: Received: 28 May 2025 — Revised: 01 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 05 Nov 2025
THPS135
Machine learning for calibration drift forecasting in superconducting RF cavities
3230
Superconducting radio frequency (SRF) cavities in particle accelerators rely on accurately calibrated RF signals to assess cavity bandwidth and detuning, ensuring optimal performance. In practice, however, calibration drift due to humidity and temperature fluctuations over time poses a significant challenge, potentially resulting in suboptimal operation and reduced efficiency. This study explores how environmental variables such as humidity and temperature affect this phenomenon. Relative humidity, in particular, is difficult to control and has been shown to impact calibration drift strongly. Building on these insights, we introduce machine learning-based approaches to forecast both relative humidity and calibration drift in SRF cavities. By leveraging advanced algorithms and historical data on cavity operation and performance, we develop predictive models that identify patterns and trends indicative of relative humidity and calibration drift. Two approaches are presented in this work, including a polynomial NARMAX model and an attention-based deep neural network. These models enable real-time compensation and automated recalibration, improving system stability and efficiency.
Paper: THPS135
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-THPS135
About: Received: 27 May 2025 — Revised: 03 Jun 2025 — Accepted: 04 Jun 2025 — Issue date: 05 Nov 2025
FRZD1
Latest achievements in femtosecond synchronization of large scale facilities
3256
The laser-based synchronisation systems for the European XFEL and FLASH provide femtosecond-stable timing references for tens of clients along the accelerator and the experiment halls over many kilometres of optical fibre. Recently, benchmarking experiments revealed a point-to-point timing stability with sub-femtosecond rms timing jitter. At the same time geophysical effects like ocean waves and earthquakes do not only affect the performance of the system, but their impact can clearly be identified. To improve the temporal resolution in X-ray/optical pump-probe experiments, additional arrival time monitors for both the electrons and the optical laser pulses are currently being installed, allowing for a posteriori data sorting and eventually active feedbacks. Further, the optical reference oscillators and advanced synchronisation schemes are being developed, resulting in timing jitter on the sub-hundred attoseconds level.
Paper: FRZD1
DOI: reference for this paper: 10.18429/JACoW-IPAC2025-FRZD1
About: Received: 30 May 2025 — Revised: 31 May 2025 — Accepted: 01 Jun 2025 — Issue date: 05 Nov 2025