THPS
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Thursday Poster Session: THPS
05 Jun 2025, 15:30 -
17:30
THPS001
Development of a customised wrapper for p4p and use of this to migrate ISIS's accelerator controls from Vsystem to EPICS
2939
The controls system for the ISIS accelerator is being migrated from using the commercial software Vsystem to EPICS which is open source. The primary protocol used for transporting process variables (PVs) across the network is pvAccess and the Python-based software p4p is used to create servers that provide access to process variables (PVA servers). A custom wrapper for p4p is being implemented to simplify and standardise way in which PVA servers work. This will allow users to easily create PVA servers for their own devices whilst allowing automatic registration with other services, for example ChannelFinder. The main device interface used for ISIS accelerator controls is an in-house developed CPS crate and these require a Vsystem reader to initialise and read channels from each CPS crate. This functionality can be replaced using the customised p4p module to provide a service that can initialise the crate and then start a PVA server to provide the PVs for that crate. This will allow decoupling the CPS crates from Vsystem so that they can be moved into EPICS.
Paper: THPS001
DOI: reference for this paper: 10.18429/JACoW-IPAC25-THPS001
About: Received: 28 May 2025 — Revised: 31 May 2025 — Accepted: 31 May 2025 — Issue date: 08 Sep 2025
Status of the control system for the injector of RAON
RAON (Rare Isotope Accelerator complex for On-line experiments), a heavy-ion linear accelerator designed to advance basic and nuclear science with rare-isotope beams, successfully completed beam commissioning and, for the first time, provided beam user service for its low-energy section using an argon beam in 2024. The successful operation of such a complex and massive accelerator system requires an integrated control system capable of real-time monitoring and control of all devices and subsystems. The RAON control system is built on the EPICS (Experimental Physics and Industrial Control System) software framework, facilitating communication with individual devices connected through PLCs or serial servers. Furthermore, each local system is equipped with interlock logic implemented using the EPICS sequencer, designed to ensure an immediate response to emergency situations. During beam delivery, operators monitor and control the entire system through OPIs (operator interfaces) built with CS-Studio in the main control room, providing comprehensive oversight and access to real-time data. This abstract presents the current status of the control system for the injector section of RAON.
Design and implementation of control system for chopper and kicker in HIAF
As important parts of the High Intensity Heavy Ion Accelerator Facility(HIAF), the Chopper and the Kicker play an indispensable role in controlling the operation mode of the beam and the protection of the machine. Accurate timing control is the key technical requirement and difficulty of this type of equipment, and it has a profound impact on the injection and extraction efficiency and beam quality of HIAF. According to the physical requirements of HIAF, this paper studies the distributed control technology of Chopper and Kicker systems, and proposes a design scheme of a general hardware platform for timing control of fast pulse devices, which mainly uses White Rabbit high-precision timing, FPGA and optical fiber transmission technology to complete the development of hardware, software and timing system interfaces, and realizes the new design of the core control system and the independent research and development of some core technologies.
THPS004
Development of new MADOCA control system for SPring-8-II
2942
The MADOCA control system was developed for the present SPring-8 in 1997. Nowadays we faced problems of outdated technologies of the MADOCA. In 2025, SPring-8 upgrade project "SPring-8-II" will be started. Toward to the SPring-8-II, we decided to renovate the MADOCA control system. The new control system inherits former MADOCA's concepts, which are characterized by SVOC-style messaging, database-oriented framework, and distributed control design using network system. In contrast with the inherited concepts, we renew the base technologies. Upgrades of messaging platform, data acquisition, and databases are already reported.\*,** We continue to develop other components. For edge computing, we use both MicroTCA.4 and generic PC server instead of outdated VME system. By combining EtherCAT with these edge computers, we support various I/O interfaces with simple wiring. We also provide REST API as database reading method to support external system linkage. Prior to the SPring-8-II project, the new control system is introduced into NanoTerasu. In this paper, we report the latest developments and prospective of the new control system.
Paper: THPS004
DOI: reference for this paper: 10.18429/JACoW-IPAC25-THPS004
About: Received: 28 May 2025 — Revised: 30 May 2025 — Accepted: 31 May 2025 — Issue date: 08 Sep 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-IPAC25-THPS005
About: Received: 03 Jun 2025 — Revised: 04 Jun 2025 — Accepted: 04 Jun 2025 — Issue date: 08 Sep 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-IPAC25-THPS006
About: Received: 28 May 2025 — Revised: 01 Jun 2025 — Accepted: 03 Jun 2025 — Issue date: 08 Sep 2025
THPS007
Oxygen deficiency detection in the LHC
2952
With the increased performance of the High Luminosity Large Hadron Collider (HL-LHC), gas leak detection in the vicinity of the superconducting magnets cooled with cryogenic helium becomes a challenge. To ensure operational safety and reliable detection of Oxygen Deficiency Hazard (ODH) for the next decade, the entire system will be refurbished during the LHC accelerator's long shutdown, scheduled to begin in 2026. The new design of the ODH detection system includes development of a detector and flashing lights that can not only cope with electromagnetic disturbances, but also with an increased radiation exposure, all while considering the restricted access for equipment maintenance. Understanding the nature and impact of these constraints at the design stage is key to specifying the requirements of the new safety systems. This paper describes the research and development work undertaken by CERN to analyse, test, and define oxygen deficiency detection taking into account lessons learned from the current systems and the future upgrade to the High Luminosity LHC.
Paper: THPS007
DOI: reference for this paper: 10.18429/JACoW-IPAC25-THPS007
About: Received: 19 May 2025 — Revised: 05 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 08 Sep 2025
THPS008
Implementation of EPU66S control system at the Taiwan Photon Source
2956
The EPU66S, an elliptically polarized undulator with a 66 mm period, is a component of the Phase III beamline project at the Taiwan Photon Source (TPS). It was successfully installed in the TPS storage ring in January 2025. The control system for the EPU66S is developed within the EPICS framework, integrating motion controllers and EtherCAT communication. This system also includes a safety interlock mechanism, which halts motion in response to limit switches, torque limit switches, emergency stop button, and linear optical encoder feedback. To ensure smooth operational testing, all hardware and software components of the EPU66S control system were fully integrated prior to installation. This paper presents the development process of the EPU66S control system, with a focus on the optimization of its motion control test platform.
Paper: THPS008
DOI: reference for this paper: 10.18429/JACoW-IPAC25-THPS008
About: Received: 27 May 2025 — Revised: 29 May 2025 — Accepted: 29 May 2025 — Issue date: 08 Sep 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-IPAC25-THPS009
About: Received: 21 May 2025 — Revised: 31 May 2025 — Accepted: 31 May 2025 — Issue date: 08 Sep 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-IPAC25-THPS010
About: Received: 21 May 2025 — Revised: 31 May 2025 — Accepted: 31 May 2025 — Issue date: 08 Sep 2025
THPS011
Operational challenges of the SuperKEKB iBump feedback system
2968
To maintain optimal beam collision conditions and luminosity performance, SuperKEKB requires a fast orbit feedback dedicated to correcting offsets at the interaction point (IP). The 'iBump' feedback system calculates IP beam offset from Beam Position Monitor (BPM) measurements before and after collision and corrects by creating closed orbit bumps in the High Energy Ring (HER). This system has demonstrated robustness at stabilising IP offsets during operation. In this paper, we discuss operational aspects of the system and ongoing challenges, with a focus on the identification of vertical offset as the correction target of the iBump system. Dedicated studies on the current dependence of this feedback target as well as historical data are analysed.
Paper: THPS011
DOI: reference for this paper: 10.18429/JACoW-IPAC25-THPS011
About: Received: 26 May 2025 — Revised: 03 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 08 Sep 2025
THPS012
Interaction point beam offset tolerances for luminosity performance at FCC-ee
2972
To achieve physics performance at the Future Circular electron-positron Collider (FCC-ee), luminosity and beam lifetime must be maintained at close to design specifications. Alongside global feedbacks, a fast feedback system is proposed to mitigate beam offset errors at the interaction points (IP), caused by magnet vibrations or other time-varying errors. In this paper, the FCC-ee luminosity performance is simulated for beam-beam interactions including beam offsets, providing performance requirements for the fast feedback system.
Paper: THPS012
DOI: reference for this paper: 10.18429/JACoW-IPAC25-THPS012
About: Received: 26 May 2025 — Revised: 01 Jun 2025 — Accepted: 03 Jun 2025 — Issue date: 08 Sep 2025
THPS013
Damping of quadrupole oscillations with bunch-by-bunch longitudinal RF feedback for FAIR
2976
To damp undesired longitudinal oscillations of bunched beams, the main synchrotron SIS100 of FAIR (Facility for Antiproton and Ion Research) will be equipped with a bunch-by-bunch longitudinal feedback (LFB) system. It will consist of new broadband kicker cavities and a dedicated low-level RF (LLRF) system. The LFB helps to stabilize the beam, to keep longitudinal emittance blow-up low and to minimize beam losses via damping dipole and quadrupole oscillations for up to 10 bunches individually. The topology of the LLRF signal processing is validated in closed loop with beam in the heavy-ion synchrotron SIS18 at GSI for future integration into SIS100. In a recent SIS18 machine development experiment with two bunches at flattop, quadrupole oscillations were excited for one bunch and then damped with a prototype setup of the LFB system using an existing magnetic alloy cavity as dedicated kicker cavity. This paper presents the test setup, the results of this experiment, and the proposed LLRF topology of the closed-loop LFB system. This validates a core part of the final SIS100 system.
Paper: THPS013
DOI: reference for this paper: 10.18429/JACoW-IPAC25-THPS013
About: Received: 19 May 2025 — Revised: 01 Jun 2025 — Accepted: 04 Jun 2025 — Issue date: 08 Sep 2025
THPS015
Implementation and evaluation of bunch-by-bunch feedback systems at PLS-II for coupled-bunch instability mitigation
2980
In synchrotron light sources, coupled-bunch instabilities driven by resonant wakefields in the vacuum chamber pose significant challenges to beam stability and quality. This study presents the implementation and evaluation of a bunch-by-bunch feedback system at the Pohang Light Source-II (PLS-II). Utilizing state-of-the-art feedback technologies, including Dimtel iGp12 baseband processors and advanced BPM hybrid networks, the system was configured to address both transverse and longitudinal instabilities. Key demonstrations include real-time grow/damp measurements, fast tune tracking, and bunch cleaning to suppress unstable modes effectively. Comparative analysis with the SPring-8 feedback system highlights performance improvements and system tuning strategies tailored to PLS-II’s operational parameters. Results from horizontal and vertical plane modal amplitudes demonstrate robust damping capabilities, maintaining beam stability even at high currents and narrow insertion device gaps. These advancements contribute to enhanced operational efficiency and higher quality photon output at PLS-II.
Paper: THPS015
DOI: reference for this paper: 10.18429/JACoW-IPAC25-THPS015
About: Received: 03 Jun 2025 — Revised: 03 Jun 2025 — Accepted: 03 Jun 2025 — Issue date: 08 Sep 2025
THPS016
A multichannel Frequency Scanning Interferometry system for large scale metrology of accelerator components
2984
In the frame of the High-Luminosity LHC (HL-LHC) project at CERN, a series of sensor solutions based on Frequency Scanning Interferometry (FSI) has been proposed for the alignment and monitoring of accelerator components along a total length of more than 800 m. The adoption of FSI technology reduces the overall cost of alignment installations, mitigates the impact of environmental noise, and limits the space required for signal cables. A development strategy for multi-channel interferometers, covering over 500 diverse FSI sensors has been put in place. This paper deals with the development and testing of the FSI interferometer. Initially, a prototype with 16 channels was installed and qualified. Following successful qualification tests, larger-scale implementations with 32 and 64 channels were deployed, enabling comprehensive tests with the entire spectrum of FSI sensors installed on a movable component. This process prepares for the deployment of the final 256-channel interferometer for the HL-LHC. This contribution presents details of the interferometer solution, encompassing optics, electronics, and software design, along with the results and analysis of the system tests.
Paper: THPS016
DOI: reference for this paper: 10.18429/JACoW-IPAC25-THPS016
About: Received: 19 May 2025 — Revised: 01 Jun 2025 — Accepted: 04 Jun 2025 — Issue date: 08 Sep 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-IPAC25-THPS017
About: Received: 23 May 2025 — Revised: 05 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 08 Sep 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-IPAC25-THPS018
About: Received: 27 May 2025 — Revised: 03 Jun 2025 — Accepted: 04 Jun 2025 — Issue date: 08 Sep 2025
Application of vibration wire pre-alignment technology in particle accelerator engineering construction
The role of large particle accelerators in basic research and applied research is becoming increasingly important. In recent years, which have put forward higher requirements for the accuracy and efficiency of particle accelerator alignment measurement. The vibrating wire pre-alignment system measures the magnetic center position of the magnet through the amplitude information of a beryllium copper wire excited in a magnetic field with alternating current, so as to adjust the four-pole and six-pole magnet of a magnet unit to the magnetic coaxial state based on this wire. This paper mainly describes the scheme design and system development process of the vibrating wire pre-alignment system, and conducts a series of test experiments to prove that the device is stable and reliable and meets the expected accuracy index requirements. This lays a solid technical foundation for the subsequent construction of large-scale particle accelerator projects.
Pre-alignment strategy for magnet units in the Hefei Advanced Light Source storage ring
The storage ring of the Hefei Advanced Light Source includes 120 magnet units, each of which is composed of 4-8 magnets with adjustment mechanisms placed on a rigid support. In order to improve the overall efficiency and accuracy of the alignment installation, we will complete the overall pre-alignment of the magnet unit in an independent laboratory with a good environment based on the vibrating line magnetic measurement technology and FLTMMS technology, and then transport the magnet unit as an independent element to the site for alignment installation. This paper elaborates on the specific implementation process of this strategy and the technical solutions adopted to improve the accuracy, such as instrument layout optimization, damping and vibration reduction. Through accuracy estimation and actual measurement verification, the implementation of this strategy can effectively ensure that the Hefei Advanced Light Source project can efficiently achieve the pre-alignment accuracy index requirements.
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-IPAC25-THPS021
About: Received: 19 May 2025 — Revised: 31 May 2025 — Accepted: 01 Jun 2025 — Issue date: 08 Sep 2025
THPS022
Consolidation of personnel safety systems at CERN
3000
Personnel Safety Systems provide prevention and mitigation barriers to protect personnel, users, equipment, and the environment against the risks associated with the operation of the CERN Accelerators and Experiments, such as Radiation, Fire, Gas and Oxygen Deficiency Hazards. Due to the obsolescence or ageing of technology, evolutions of the facility and the Safety rules, it is now time to consolidate existing safety systems to prepare the CERN complex for the coming decades. A dedicated program has therefore been launched to refurbish the Fire, Gas and Oxygen Deficiency Hazard Detection Systems, and to implement a new Voice Alarm and Evacuation System in the Large Hadron Collider, among others. The paper provides insight into the methodology used to define the appropriate safety levels required to pragmatically ensure the Safety of personnel and the environment in the facility. Lessons learned from 20 years of operation, interpretation of the legal framework, and the process of risk definition and reduction through preventive and protection measures will be discussed. The main ongoing projects and the challenges ahead of the teams in charge will also be briefly presented.
Paper: THPS022
DOI: reference for this paper: 10.18429/JACoW-IPAC25-THPS022
About: Received: 23 May 2025 — Revised: 31 May 2025 — Accepted: 02 Jun 2025 — Issue date: 08 Sep 2025
THPS023
Renovation of the technical gallery network at CERN
3003
The distribution of services throughout a large scientific facility like CERN relies on a 14-km-long network of technical galleries. They provide essential utilities to CERN's office buildings and technical facilities, such as hot water, drinking water, compressed air, gas and electrical supply. This network has been gradually expanded or partially discontinued based on the Laboratory's needs. After 60 years of service, it is now time to refurbish the galleries and their associated infrastructure, to address existing issues and establish a robust foundation for the organization's future endeavors. A dedicated project has therefore been launched to enhance the maintainability, reliability, overall safety, and environmental performance of the technical infrastructure. Adapting all the networks to current and future needs following modern standards while minimizing service disruptions is also a priority. This paper provides insight into the methodology developed to re-engineer the targeted areas, the results of design studies, and lessons learned from implemented improvements. These insights may serve as a valuable example for other consolidation projects within CERN and beyond.
Paper: THPS023
DOI: reference for this paper: 10.18429/JACoW-IPAC25-THPS023
About: Received: 23 May 2025 — Revised: 03 Jun 2025 — Accepted: 04 Jun 2025 — Issue date: 08 Sep 2025
THPS024
Radiation monitoring and R2E performance in the LHC during the 2024 proton run
3006
The integrated luminosities in each of the ATLAS and CMS experiments at the Large Hadron Collider (LHC) have reached above 120 fb-1 during the proton run of 2024, the highest annual values since the beginning of the LHC operation. The same is true for LHCb, with over 10 fb-1 of integrated luminosity reached during proton operation in 2024. Such high levels of integrated luminosity are associated with high levels of radiation around the experiment locations, including hundreds of meters of tunnel on both sides of the interaction point, where beam losses driven by the luminosity production still occur. The ability of the LHC systems to operate in the radiation environment of the machine is analyzed in this contribution. Each year, radiation effects on electronic components installed around the LHC lead to premature beam dumps, causing accelerator down-time and loss of physics production. The number of radiation-induced beam dumps of the proton run 2024 per integrated luminosity has been comparable to previous years in LHC Run 3, and improved compared to LHC Run 2. However, due to the large integrated luminosity of LHCb, a large part of the events have been observed there, and some mitigation strategies to minimize such events are discussed.
Paper: THPS024
DOI: reference for this paper: 10.18429/JACoW-IPAC25-THPS024
About: Received: 27 May 2025 — Revised: 02 Jun 2025 — Accepted: 04 Jun 2025 — Issue date: 08 Sep 2025
THPS025
Passive Radiation Detection Using TLD in NSRRC
3010
The NSRRC is a research facility and currently op-erates two synchrotron accelerators: the Taiwan Light Source (TLS), featuring a beam energy of 1.5 GeV and a circumference of 120 meters, and the Taiwan Photon Source (TPS), with a beam energy of 3 GeV and a cir-cumference of 518.4 meters. There are hundreds of users in 40 beamlines among TPS and TLS experi-mental floors. The Thermo-Luminescent Dosimeter (TLD) is a compact instrument utilizing well-established detec-tion technology. To ensure radiation intensity at NSRRC workplace as close to background radiation levels as possible, we have deployed approximately 200 TLDs among these two accelerators. For each BL, three points are selected: the optical hutch near accel-erator shielding wall, the user experimental area with the highest occupancy, and the BL rear end. Additional TLDs are strategically placed around the accelerator's surroundings, including both the outer and inner sur-face of the shielding tunnel, downstream of the injec-tion section, the roof and downstream area of the RF cavities. In this paper, we will present the detection data col-lected at NSRRC over the past several years to reflect the proficiency of our radiation protection program.
Paper: THPS025
DOI: reference for this paper: 10.18429/JACoW-IPAC25-THPS025
About: Received: 06 May 2025 — Revised: 02 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 08 Sep 2025
THPS026
Reliability analysis of the new Beam Interlock System for CERN’s accelerator complex
3014
The Beam Interlock System is a key element of machine protection in CERN’s accelerators. It provides a fast and reliable way to link the accelerator systems to the beam dumping system, which ensures the safe extraction of the beams. This paper presents the reliability study of the new Beam Interlock System, which will replace the current system and will be deployed during CERN’s Long Shutdown 3. The upgrade features many improvements while maintaining the proven architecture of the previous system. In the study, each of the system’s boards were analysed through a detailed, component-level FMECA. This approach quantifies all operational risks, as well as identifies the most critical components. The risk on the system level is estimated using a global reliability model, which establishes functional dependencies between individual boards. It accounts for system-level redundancies, inspection and maintenance strategies. The results show that the stringent reliability requirements, set in the view of possible catastrophic damages to the equipment in case of malfunction, are met with safety margins. They also highlight the importance of appropriate maintenance, testing and monitoring.
Paper: THPS026
DOI: reference for this paper: 10.18429/JACoW-IPAC25-THPS026
About: Received: 28 May 2025 — Revised: 31 May 2025 — Accepted: 05 Jun 2025 — Issue date: 08 Sep 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-IPAC25-THPS027
About: Received: 26 May 2025 — Revised: 30 May 2025 — Accepted: 31 May 2025 — Issue date: 08 Sep 2025
THPS028
Reliability analysis of the new Universal Quench Detection System and Protection Devices Supervision Unit for the HL-LHC inner triplet magnets
3022
The new Universal Quench Detection System (UQDS) and Protection Devices Supervision Unit (PDSU) are pivotal elements for the quench protection system of the new HL-LHC inner triplet superconducting magnets as well as for requesting a beam dump upon activation of the active quench protection systems, the novel Coupling Loss Induced Quench System (CLIQ) and the traditional quench heaters (HDSs). Given the criticality of these functionalities, a thorough reliability analysis has been carried out to ensure that the probability of critical failures meets the stringent reliability requirements under all operational conditions. To determine the failure probabilities, analytical models were developed that consider redundancies, inspection strategies and demand frequencies. The models’ failure parameters were identified by a component-based Failure Mode, Effects and Criticality Analysis (FMECA). The results of the models allow the qualification of the system design as well as insights on critical monitoring and testing requirements of the system when in operation.
Paper: THPS028
DOI: reference for this paper: 10.18429/JACoW-IPAC25-THPS028
About: Received: 28 May 2025 — Revised: 03 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 08 Sep 2025
THPS029
Experience with the CERN LINAC4 and its performance during the first four years of operation
3026
Since 2020 LINAC4 provides the protons for the entire CERN accelerator complex. It accelerates H- ions to a kinetic energy of 160 MeV and injects them into the Proton Synchrotron (PS) Booster using a charge exchange injection mechanism. The performance requirements have been successfully met since 2021. This paper presents the operational experience gained, together with availability and reliability statistics for LINAC4, during its first four years of operation, and details the key performance indicators for beam quality and stability. It also discusses the main issues encountered and the implemented solutions that have allowed further improvements to be made. Recent developments on the H- ion source have led to an increase of the beam current from the original 35 mA to 50 mA, opening the possibility to increase the intensity delivered to the PS Booster for the benefit of CERN's experimental programmes. Beam energy modulation in LINAC4 has also been developed to increase the PS Booster bunch intensity for which the results of beam tests are presented.
Paper: THPS029
DOI: reference for this paper: 10.18429/JACoW-IPAC25-THPS029
About: Received: 27 May 2025 — Revised: 31 May 2025 — Accepted: 04 Jun 2025 — Issue date: 08 Sep 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-IPAC25-THPS030
About: Received: 20 May 2025 — Revised: 30 May 2025 — Accepted: 01 Jun 2025 — Issue date: 08 Sep 2025
Daily performance variations of the LCLS-II super conducting accelerator
Starting with user delivery it was noticed that the FEL intensity performance varied by up to a factor of two during the day. Three injector RF phases for the laser, the gun, and the buncher were not stabilized with a forward and reversed reference signals like the rest of the RF feeding the Cryo-Modules, making them the prime candidates for daily phase drifts. Combining the signals in hardware, firmware and software and temperature stabilizing critical RF cables improved the situation. Additionally, how downstream beam parameters like energy, bunch length, and orbits respond to phase changes of laser, gun, and buncher were quantified, so that the observed daily changes could be attributed to the most likely combination of still uncorrected phase drifts. A feed-forward system similar to the RF of the copper linac using the local temperature was developed to compensate for the remaining changes. Longitudinal feedbacks should see minimal amounts for intervention.
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-IPAC25-THPS032
About: Received: 26 May 2025 — Revised: 31 May 2025 — Accepted: 04 Jun 2025 — Issue date: 08 Sep 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-IPAC25-THPS033
About: Received: 30 May 2025 — Revised: 05 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 08 Sep 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-IPAC25-THPS034
About: Received: 26 May 2025 — Revised: 02 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 08 Sep 2025
THPS035
Detector protection system used in the Taiwan Photon Source 13A experimental station
3043
At the Taiwan Photon Source 13A experimental station, the detector is prone to noise interference in a vacuum environment ranging from 750 torr to 7 mtorr, which can lead to malfunctions. Therefore, a rapid automatic power-off system has been designed to immediately shut down the detector's power when it is in an abnormal vacuum range, reducing the impact of noise on the detector and thereby extending its lifetime.
Paper: THPS035
DOI: reference for this paper: 10.18429/JACoW-IPAC25-THPS035
About: Received: 27 May 2025 — Revised: 31 May 2025 — Accepted: 03 Jun 2025 — Issue date: 08 Sep 2025
THPS036
Intelligent motor driver monitoring and alarm system for Taiwan Photon Source
3046
The number of motor drivers in the TPS beamline and experimental stations is quite large. Therefore, designing an intelligent monitoring and alert system to monitor the motor control system on the beamline is essential. When the system encounters any abnormal conditions, it can notify engineers to handle the situation. Additionally, it can record usage time to schedule relevant replacement work, thereby improving operational efficiency.
Paper: THPS036
DOI: reference for this paper: 10.18429/JACoW-IPAC25-THPS036
About: Received: 27 May 2025 — Revised: 31 May 2025 — Accepted: 05 Jun 2025 — Issue date: 08 Sep 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-IPAC25-THPS038
About: Received: 27 May 2025 — Revised: 31 May 2025 — Accepted: 04 Jun 2025 — Issue date: 08 Sep 2025
High-dimensional single-shot optical field compressive diagnostic
Laser field diagnostic has long been limited by dimensions of obtained information and one-shot measurement ability. The term “dimension” refers to spatiotemporal distributions, but also physical quantities completely defining a light field including amplitude, phase and polarization. Conventional diagnostic systems realize multi-shot or incomplete measurements of laser optical field, but are limited to characterize actual low-repetition, complex “structured” laser fields. A full characterization of spatiotemporal quantities of light field is essential, as the accelerated electron bunch distributions and qualities are highly dependent on the incident complex laser. A full characterization of complex structured light fields will be a potential tool for the single shot, high dimensional electron bunch diagnostic. Here we proposed the technique of high-dimensional single-shot optical field diagnostic, resolving full-dimensional information of arbitrary spatiotemporal inhomogeneous laser fields. It is believed that this novel light detection technique can not only be further compactly implemented for pre-diagnostic of electron acceleration, but also observe 3D electron bunch dynamics.
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-IPAC25-THPS040
About: Received: 28 May 2025 — Revised: 30 May 2025 — Accepted: 03 Jun 2025 — Issue date: 08 Sep 2025
Design and status of LLRF system for PREF linac
The Proton radiation effects facility (PREF) was designed and constructed by the Institute of Modern Physics, which can provide high-quality proton beams with continuous and accurate tunable energy range, high current intensity, high duty cycle and large scanning area of 10-60MeV energy range. which consists of a proton source, RFQ linac injector, synchrotron and irradiation terminals. The RFQ works at 162.5 MHz, providing 1.2Mev proton beam for synchrotron. The RF system consists of a RFQ cavity, two 50 kW solid state amplifiers and digital low level RF control system (LLRF). The amplitude and phase stability requirements for the LLRF are 1% and ±1°separately. To meet requirements and to ensure reliability, a digital LLRF system was designed. The new digital LLRF is based on Virtex5 FPGA, fast ADCs and DACs, and CPCI bus. The progress and plans for future are presented.
THPS042
Evaluation of an X-band LLRF prototype for the EuPRAXIA@SPARC_LAB LINAC
3054
EuPRAXIA, the "European Plasma Research Accelerator with eXcellence In Applications," represents the next generation of free-electron lasers (FEL). It aims to develop a compact, cost-efficient particle accelerator using innovative wake-field accelerator technology. High-energy physics often demands higher acceleration voltages, and X-band technology offers high gradients in compact structures. The EuPRAXIA@SPARC_LAB LINAC injector, featuring an S-band RF gun, four S-band structures, and sixteen X-band structures, achieves a maximum beam energy of 1 GeV. For femtosecond-level synchronization and stability, Low-Level Radio Frequency (LLRF) systems are essential. However, commercial X-band LLRF solutions are unavailable. This project, in context of the EuPRAXIA - Doctoral Network, develops an X-band LLRF prototype tailored to meet the EuPRAXIA@SPARC_LAB LINAC's stringent requirements. After validation on a testbench, the prototype will enable industrial production and commercialization. This paper presents the Front-End, Back-End analysis, and further evaluation of the prototype.
Paper: THPS042
DOI: reference for this paper: 10.18429/JACoW-IPAC25-THPS042
About: Received: 27 May 2025 — Revised: 02 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 08 Sep 2025
THPS043
A new EPICS based frequency synthesizer and power control system for the H¯ RF Ion Source at ISIS
3058
A Low-Level RF and Power Control system based on EPICS has been developed for the new H¯ RF Ion Source on the Pre-Injector Test Stand at ISIS Spallation Neutron and Muon source, UKRI-STFC Rutherford Appleton Laboratory. The Ion Source LLRF system provides a 2 MHz signal to a Solid-State 100 kW RF Amplifier that drives the Ion Source Plasma, the changing Plasma load requires fast Frequency agility and closed loop Power Control. This paper will detail the design and performance of the LLRF system.
Paper: THPS043
DOI: reference for this paper: 10.18429/JACoW-IPAC25-THPS043
About: Received: 28 May 2025 — Revised: 04 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 08 Sep 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-IPAC25-THPS044
About: Received: 24 May 2025 — Revised: 30 May 2025 — Accepted: 01 Jun 2025 — Issue date: 08 Sep 2025
THPS045
The PIP-II dedicated RFPI system final design
3064
The Radio Frequency Protection Interlock (RFPI) system main responsibility is to collect predefined set of signals and to protect each RF station. In case of safety limits violations from any of this input signals the RFPI has to instantenously drop permits for the LLRF or RF amplifier (eq. Solid State Amplifier - SSA or klystron) operation. This paper presents an overview of the final design of the RFPI system dedicated for Proton Improvement Plan II (PIP-II) at Fermilab.
Paper: THPS045
DOI: reference for this paper: 10.18429/JACoW-IPAC25-THPS045
About: Received: 28 May 2025 — Revised: 04 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 08 Sep 2025
THPS046
The LLRF related superconducting elliptical cavities characterization for ESS project
3068
The installation phase of the European Spallation Source (ESS) linear accelerator is nearly complete. As with other superconducting linacs operating in pulse mode, LLRF systems play a crucial role in controlling accelerating beam parameters. Modern LLRF systems go beyond providing fast and reliable feedback for RF signal regulation; they also ensure precise, dynamic cavity tuning. Additionally, they enhance machine availability by monitoring various signals to identify potential issues and implementing fast and slow algorithms to optimize cavity performance within safety limits, tailored to specific accelerator conditions. Preparation for these tasks begins during cryomodule and cavity testing, prior to tunnel installation. Key parameters such as Lorentz force detuning coefficients, piezotuner range and polarity, main mechanical cavity modes, Pi-mode frequencies, slow tuner sensitivity, and backlash must be accurately determined to enable peak LLRF performance. This paper outlines the development, implementation, and application of software tools designed to determine these parameters for cavities tested at ESS Test Stand 2 (TS2) and those installed in the accelerator tunnel.
Paper: THPS046
DOI: reference for this paper: 10.18429/JACoW-IPAC25-THPS046
About: Received: 28 May 2025 — Revised: 04 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 08 Sep 2025
THPS047
Fully experiment request driven beta* and separation luminosity levelling at the LHC
3072
During the third run period (2022-2026) of the CERN Large Hadron Collider (LHC), as well as for the future High-Luminosity LHC era, luminosity levelling is key to control the event pile-up in the experiments as well as the heat load to the cryogenic system of the superconducting magnets close to the interaction points. During 2024 proton physics operation, a new luminosity levelling scheme was introduced for the high-luminosity experiments, ATLAS and CMS. Combining levelling by optical squeeze (beta*) with small transverse separation changes gives the beam stability benefits of beta* levelling (head-on tune spread and landau damping) while keeping the flexibility of separation levelling (independent levelling for each experiment in arbitrary steps of luminosity). This not only allowed each experiment to set their luminosity target independently, but also reduced the luminosity spread during levelling from 5%, when using just beta* levelling, to less than 3%, resulting in a more homogeneous data set.
Paper: THPS047
DOI: reference for this paper: 10.18429/JACoW-IPAC25-THPS047
About: Received: 22 May 2025 — Revised: 30 May 2025 — Accepted: 30 May 2025 — Issue date: 08 Sep 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-IPAC25-THPS048
About: Received: 10 Jun 2025 — Revised: 14 Jun 2025 — Accepted: 14 Jun 2025 — Issue date: 08 Sep 2025
Towards autonomous accelerator control at ALS: a multi-agent LLM approach
This paper demonstrates progress towards a novel approach to particle accelerator control at ALS using a decentralized multi-agent framework powered by Large Language Models (LLMs). Our distributed control system deploys specialized autonomous agents to manage critical accelerator subsystems while maintaining coordinated operation through LLM-driven communication protocols. The system demonstrates fundamental capabilities essential for next-generation accelerator operations, given the flexible nature of agent specialization, this framework provides a robust platform for integrating and coordinating diverse control algorithms and approaches already established in accelerator operations. Our prototype shows the system's ability to autonomously diagnose and resolve basic operational issues using existing control infrastructure. This work represents an advancement toward practical autonomous accelerator operation, establishing a scalable foundation for managing increasingly sophisticated accelerator configurations. The demonstrated success of this distributed control architecture opens new possibilities for improving operational efficiency across various accelerator facilities.
THPS050
Development of a flexible digital twin framework for accelerators using design patterns
3080
These days designing an accelerator consist of prototyping and testing adequate commissioning software. Digital twins serve as natural test benches for validating and monitoring the required physics software stack. These twins must align with the current design state of the accelerator from the project's inception to the machine's commissioning. The authors have developed a modern digital twin framework based on software design patterns. Its architecture emphasizes clean design principles with minimal coupling between components. Its setup requires only lattice and device configuration data. Thanks to its design, it seamlessly integrates into prototyping environments or control system infrastructures. In this paper, we briefly describe the design patterns underlying this architecture, highlight the flexibility and advantages of the infrastructure, and outline the steps needed to implement it for a machine currently lacking a digital twin.
Paper: THPS050
DOI: reference for this paper: 10.18429/JACoW-IPAC25-THPS050
About: Received: 25 May 2025 — Revised: 01 Jun 2025 — Accepted: 04 Jun 2025 — Issue date: 08 Sep 2025
Development progress of high-level applications for the HEPS
To meet the beam commissioning requirements of the High Energy Photon Source (HEPS), a brand-new framework called Pyapas was developed using pure Python. All high-level applications (HLAs) for the HEPS are being built upon this framework. The beam commissioning of the Linac started on March 9, 2023, and the HLAs performed excellently, helping the Linac to successfully complete the test and acceptance. By mid-2023, the development of all HLAs for the booster was successfully completed, paving the way for beam commissioning, which began in late July and concluded with in its successful acceptance in November 2023. By June 2024, the development of HLAs for storage ring was completed, followed by multiple rounds of offline testing iterations and joint tests with the hardware system. These efforts ensured the readiness of the HLAs, which supported the successful commissioning of the storage ring and the emission of its first light in October 2024. This paper provides a comprehensive review of the recent progress in the development of HEPS HLAs, emphasizing milestones achieved during the booster and storage ring commissioning, and outlines the roadmap for future development.
Service-oriented EPICS and data processing method based on high-availability cluster
A novel service-based EPICS and new front-end data acquisition method based on a high-availability Kubernetes cluster built on the Proxmox VE platform are proposed in this paper to enhance the performance and stability of the data acquisition system. By deploying EPICS services on the Kubernetes cluster, a new efficient front-end data processing and acquisition method is realized. The data acquisition method utilizes distributed data sharing based on the Channel Access protocol to perform real-time processing and analysis of data. This approach offers advantages such as reducing hardware and maintenance costs, improving portability and flexibility, and enhancing data acquisition and processing efficiency. The practical application and testing have demonstrated that this method has the potential for use in large scientific facilities. In the future, its application value in other fields will be explored.
THPS053
Integrating community codes for accelerator design and optimization
3083
Advances in fidelity and performance of accelerator modeling tools, in tandem with novel machine learning capabilities, has prompted community initiatives aiming to realize “virtual test stands” that can serve as true analogues to physical machines. Such efforts require integrated, end-to-end modeling capabilities with support for parametric optimization and benchmarking. We present the ongoing development of an integrated Sirepo application to support the holistic modeling of accelerators. Our approach leverages existing modeling workflows, such as the Light Source Unified Modeling Environment (LUME), as well as community I/O frameworks, such as openPMD, to provide a toolbox for constructing and modeling beamlines. Users can build and test simulations using different community modeling tools, as well as connect individual tools to produce end-to-end simulations. Additional workflows have been developed to support machine learning tools that facilitate optimization and the development of surrogate models. We discuss some specific beamline modeling demonstrations as well as ongoing efforts to support code-agnostic design and development.
Paper: THPS053
DOI: reference for this paper: 10.18429/JACoW-IPAC25-THPS053
About: Received: 29 May 2025 — Revised: 04 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 08 Sep 2025
THPS054
State-of-the-art cryogenics process control for the operation of the ESS superconducting linac
3086
This paper presents the strategy for the simultaneous cryogenic operation of the ESS superconducting linac, consisting of 43 cryomodules. It details the process logic required for different operational phases and introduces a novel control system designed to manage these complexities. Key features of the system are discussed, including multiple independent automatic control sequences, a master controller for system synchronization, failure response protocols, and operator interface design. Fully deployed in December 2024, the system played a critical role in the successful cooldown of the accelerator. The paper also addresses lessons learned during this deployment and outlines potential improvements for future operations.
Paper: THPS054
DOI: reference for this paper: 10.18429/JACoW-IPAC25-THPS054
About: Received: 28 May 2025 — Revised: 30 May 2025 — Accepted: 30 May 2025 — Issue date: 08 Sep 2025
THPS055
First cryogenics operational experience of the ESS cryomodules in LINAC configuration
3090
This paper presents the first operational experience of the European Spallation Source (ESS) cryomodules in a linac configuration, with a focus on the challenges encountered during the initial integrated cooldown and subsequent stable operation. Key aspects such as thermal stability, cryogenic performance, and system integration are discussed in detail. The paper also highlights lessons learned during the operation, identifies areas for improvement, and proposes strategies for optimizing cryogenic operations in the upcoming phases of the ESS project.
Paper: THPS055
DOI: reference for this paper: 10.18429/JACoW-IPAC25-THPS055
About: Received: 28 May 2025 — Revised: 30 May 2025 — Accepted: 31 May 2025 — Issue date: 08 Sep 2025
Upgrade of variable frequency drive for cryogenic system at NSRRC
After nearly two decades of continuous operation, the Variable Frequency Drive (VFD) of Main Cryogenic Plant 1 (MCP1) experienced a critical failure following a routine shutdown in September 2021. Despite thorough inspection and part replacement, the root cause of the failure remained elusive. Additionally, several seemingly normal spare parts were found to be damaged. Given the discontinued production of many spare parts and the presence of two identical VFDs in operation, a decision was made to upgrade the entire MCP1 VFD. After undergoing specific customizations, the new VFD was retrofitted and commenced testing in late 2021. During the dismantling process of the original VFD, the underlying cause of the failure was uncovered: a short circuit resulting from damaged power wiring. This paper delves into the distinctions between the original and new VFDs, outlines the customized modifications, and presents the comprehensive test results of the upgraded system. Furthermore, the root cause of the failure and the extent of damage inflicted by the old VFD will be discussed.
THPS058
Cryogenic inserts in the room temperature synchrotron SIS18 at GSI
3094
The existing room temperature heavy ion synchrotron SIS18 at GSI will be used as booster for the future SIS100 at FAIR. One of its features the the generation of high intensity heavy ion beams. In order to create such beams, medium charge states are used, which have a lower space charge limit and can be created with less stripping losses. Unfortunately, such heavy ions have very high ionization cross sections in collisions with residual gas particles, yielding in beam loss and subsequent pressure rises via ion impact stimulated gas desorption. Although an extensive upgrade plan, including NEG-coated magnet chambers and an ion-catcher system, has been realized, the required intesity goals will not yet be reached. Simulations including cryogenic surfaces around the ion catchers show, that their high sticking probability prevents from pressure built-ups during operation. A prototype ion catcher, including such cryogenic surfaces cooled by a commercial cold-head has been developed, built, and tested. It has recently been installed in SIS18 and will undergo further tests, including measurements with heavy ion beams. Findings for the operation and further cryogenic inserts are presented.
Paper: THPS058
DOI: reference for this paper: 10.18429/JACoW-IPAC25-THPS058
About: Received: 20 May 2025 — Revised: 30 May 2025 — Accepted: 31 May 2025 — Issue date: 08 Sep 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-IPAC25-THPS059
About: Received: 19 May 2025 — Revised: 30 May 2025 — Accepted: 30 May 2025 — Issue date: 08 Sep 2025
THPS060
Photon stimulated desorption from cryogenic surfaces of high temperature superconductor and amorphous carbon thin films
3101
High Temperature Superconductor (HTS) and amorphous Carbon (a-C) thin films, and their combination, are being considered as possible surface coatings for the FCC-hh beam screen (BS) with the aims of reduction of the resistive wall impedance and mitigation of the electron cloud. Along with these required properties, i.e., the high electron conductivity and low secondary electron yield, the Photon Stimulated Desorption (PSD) yield is one of the most essential characteristics in the design and operation of the FCC-hh vacuum systems. For this purpose, a series of the PSD measurements is currently conducted at a dedicated beamline in the KEK Photon Factory, where similar conditions to FCC-hh in terms of the Synchrotron Radiation energies and power density are available. In order to realize a similar cryogenic condition of the BS (40-60 K), the sample container is equipped with a LN2 jacket (77 K) and installed in an insulation vacuum chamber. The conditioning behaviors of the PSD yields as a function of the photon dose are being obtained for uncoated copper and HTS, and a-C coated copper and HTS, and each sample is examined at cryogenic and room temperatures for comparative analysis.
Paper: THPS060
DOI: reference for this paper: 10.18429/JACoW-IPAC25-THPS060
About: Received: 31 May 2025 — Revised: 02 Jun 2025 — Accepted: 03 Jun 2025 — Issue date: 08 Sep 2025
THPS061
Surface resistance measurement of Pd coating films using cavity resonator method
3105
Recently, it was found that Pd coating films exhibited ultra-low photon-stimulated desorption and low resistivity values. These advantages suggest that Pd coatings could be applied to small aperture tubes, including undulator vacuum tubes, which have a significant effect on resistive wall impedance. In previous studies, the DC electrical resistivity of Pd films was measured using the four-probe technique. The surface resistance under high-frequency conditions relevant to accelerators remained insufficiently explored. This study aims to address this gap by employing the “cavity resonator method” to measure the surface resistance of this film under high-frequency electromagnetic fields. By depositing Pd films onto the inner surface of a copper alloy resonator, the quality factor (Q-factor) was measured and compared to that of the uncoated copper alloy, allowing for the calculation of the practical surface resistance. These results could provide a basis for evaluating the heat generation and cooling requirements of this film in accelerator applications.
Paper: THPS061
DOI: reference for this paper: 10.18429/JACoW-IPAC25-THPS061
About: Received: 28 May 2025 — Revised: 04 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 08 Sep 2025
Design and commissioning of BRing vacuum system
The Booster Ring (BRing), which requires an average vacuum to be better than the 10-10Pa，is the key part of the High Intensity Heavy Ion Accelerator Facility. The total length of BRing is 569.0985 meters, the characteristics of long circumference, large cross-section and a large amount of gas load, pose great challenges for on-site installation and achieving the vacuum index. Therefore, optimization has been carried out from several aspects. Firstly, in order to reduce eddy current, 0.3mm thick low permeability stainless steel is required. Different from the commonly used ceramic vacuum chamber or 0.3mm thin-walled chamber with ribs, the structure of placing high-strength, low gas load inner lining skeleton at intervals inside the 0.3mm thin-walled chamber is proposed for the first time. Using 3D printing technology to process the inner lining skeleton and coating it with getter film to reduce the pressure gradient. Secondly, the kicker chambers are equipped with ferrite, which brings high gas load. So a process for reducing the outgassing rate of ferrite has been explored, which can make the outgassing rate of ferrite ≤ 1.125×10-9Pa.L.S-1.cm-2. After testing, the vacuum of the kicker chamber is better than 7×10-10Pa. Thirdly, the pressure distribution of BRing was calculated by Molflow software, and the pumping scheme has been optimized. The BRing vacuum system has been installed, and the entire ring has undergone on-site baking, with an average vacuum better than 7×10-10Pa.
Study on the vacuum properties of titanium alloy-lined thin-walled arc vacuum chamber
A large scientific facility, High Intensity heavy-ion Accelerator Facility (HIAF), was being built to study basic and interdisciplinary sciences. The Booster ring (BRing), as the core device of the HIAF, has a magnetic rigidity of up to 34 Tm，and the field ramping rate of the pulsed dipole magnet is up to 12 T/s. To reduce the eddy current effect and beam loss caused by the rapid ramping of the magnetic field. A 0.3 mm stainless steel thin-walled titanium alloy lined arc vacuum chamber was proposed, in which titanium alloy liners are sequentially arranged inside to improve mechanical properties. The arc vacuum chamber with a cross-section of 230 mm x 97 mm and a length of 3.4 m，to reduce the pressure gradient inside the thin-walled arc vacuum chamber，Ti-Zr-V thin films were deposited on the titanium alloy liner and 0.3 mm stainless steel thin wall, respectively, by magnetron sputtering coating technology. After activation of Ti-Zr-V thin films，the ultimate pressure can be as low as 5.0E-10 Pa, and the pressure at the middle of the thin-walled arc vacuum chamber could decreased from 1.5E-9 Pa to 6.6E-10 Pa. Furthermore, 0.3mm thin-walled titanium alloy lined arc vacuum chamber and Ti-Zr-V thin films have been successfully applied to HIAF-BRing.
Development of metal vacuum chamber with low eddy currents under high frequency magnetic fields
HIAF-BRing, the booster synchronous ring of the High Intensity Heavy-Ion Accelerator Facility, is rapid cycling synchrotron. It requires a vacuum pressure of 5 ×10 -10Pa and a vacuum pipeline that generates small eddy currents under high-frequency magnetic fields of 12 T/s. A new type of vacuum chamber has been successfully developed to reduce effectively the eddy current effect. It also significantly reduces the gap of the dipoles and quadrupoles, compared to the thin-walled stainless steel vacuum chamber with reinforced ribs. The chamber consists of stainless steel pipe with a thickness of 0.3mm and ceramic lining rings. Ceramic rings are gradually and intermittently arranged along the pipeline as a support frame for metal thin-walled chamber. High strength ceramics and stainless steel of the chamber can be baked safely at 300 ℃. Through experimental testing, vacuum pressure of the chamber reaches 4.2 × 10-10pa. The ceramic rings are Au-coated to effectively reduce the beam impedance and the desorption rate of ceramic materials.
Upgrade of IR-FEL low-level RF control system based on beam load feedforward
Hefei Infrared Free-Electron Laser device (IR-FEL) is a user experimental device dedicated to energy chemistry research that can generate high brightness mid/far infrared lasers. It is driven by an S-band linear accelerator with a maximum electron energy of 60 MeV. The stability of the final laser output is determined by the quality of the electron beam, and optimizing the Low-Level RF (LLRF) Controlsystem can elevate the beam's ultimate quality. The IR-FEL linear accelerator boasts a beam length of 13μs, exhibiting a pronounced beam loading effect. The leading edge of the beam interacts with the RF field, absorbing energy, thereby influencing the acceleration process at the beam's tail. This interaction leads to an increase in beam emittance, impacting the final laser quality. However, by incorporating a feedforward algorithm to modulate the microwave field amplitude upon the beam's arrival, we can mitigate the beam loading effect and improve beam quality. Details regarding this upgrade, along with the experimental outcomes, will be elaborated upon in the main text.
THPS066
PAnTHer: An interactive map for the web and touchscreens
3108
PAnTHer (Particle Accelerator on THreejs) is a 3D and 2D map for particle accelerators developed using web and touch technologies. The maps are connected to real-time data from accelerator controls, simulators, and an external component database. The map is generated from a lattice file in JSON format and a bundle of JavaScript components for the 3D version, and an SVG bundle for the 2D version. The JSON lattice file can be generated on the fly taking all necessary parameters from a simulator device server and presented instantly to the remote user among with the visualization of some simulated quantities such as position, beta, eta, mu and sigma Available components are: magnets (bending, quadrupoles, sextupoles, correctors, etc.), pumps, valves, PLCs, racks, mirrors, walls etc. Multiple components can be embedded within a single element. The 3D version offers various configurations, ranging from a fast mode, which runs smoothly even on devices with limited computational power, to a standard mode with enhanced graphical details, and a high resolution mode that uses components derived from mechanical department. The latter requires fairly powerful hardware to maintain optimal fluidity.
Paper: THPS066
DOI: reference for this paper: 10.18429/JACoW-IPAC25-THPS066
About: Received: 27 May 2025 — Revised: 30 May 2025 — Accepted: 30 May 2025 — Issue date: 08 Sep 2025
Integrated denoising for improved stabilization of RF cavities
Typical operational environments for industrial particle accelerators are less controlled than those of research accelerators. This leads to increased levels of noise in electronic systems, including radio frequency (RF) systems, which make control and optimization more difficult. This is compounded by the fact that industrial accelerators are mass-produced with less attention paid to performance optimization. However, growing demand for accelerator-based cancer treatments, imaging, and sterilization in medical and agricultural settings requires improved signal processing to take full advantage of available hardware and increase the margin of deployment for industrial systems. In order to improve the utility of RF accelerators for industrial applications we have developed methods for removing noise from RF signals and characterized these methods in a variety of contexts. Here we expand on this work by integrating denoising with pulse-to-pulse stabilization algorithms. In this poster we provide an overview of our noise reduction results and the performance of pulse-to-pulse feedback with integrated ML based denoising.
Automation of sample alignment for neutron beamlines
Neutron scattering experiments are a critical tool for the exploration of molecular structure in compounds. The TOPAZ single crystal diffractometer at the Spallation Neutron Source and the Powder Diffractometer at the High Flux Isotope Reactor study these samples by illuminating them with different energy neutron beams and recording the scattered neutrons. Aligning and maintaining the alignment of the sample during an experiment is key to ensuring high quality data are collected. At present this process is performed manually by beamline scientists. RadiaSoft in collaboration with the beamline scientists and engineers at ORNL has developed a machine learning based alignment software automating this process. We utilize a fully-connected convolutional neural network configured in a U-net architecture to identify the sample center of mass. We then move the sample using a custom python-based EPICS IOC interfaced with the motors. In this poster we provide an overview of our machine learning tools and show our results aligning samples at ORNL.
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-IPAC25-THPS071
About: Received: 28 May 2025 — Revised: 05 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 08 Sep 2025
THPS072
Real-time luminosity optimization in collider experiments using reinforcement learning
3115
This study presents the development and implementation of a reinforcement learning-based algorithm for real-time luminosity tuning in collider experiments. The algorithm is initially pretrained on historical collider data and subsequently fine-tuned online during experiments. By analyzing accelerator measurements collected over several seconds, the model adjusts the magnetic structure to stabilize luminosity under varying experimental conditions. The proposed method allows for adaptive optimization without operator involvement, improving operational efficiency and stability. Results from its application on the VEPP-4M collider are presented, showcasing the method's feasibility and offering insights for its future development and application in accelerator systems.
Paper: THPS072
DOI: reference for this paper: 10.18429/JACoW-IPAC25-THPS072
About: Received: 28 May 2025 — Revised: 03 Jun 2025 — Accepted: 04 Jun 2025 — Issue date: 08 Sep 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-IPAC25-THPS073
About: Received: 28 May 2025 — Revised: 05 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 08 Sep 2025
Automatic online optimization at the SXFEL facility
The commissioning phase of short-wavelength FEL is often lengthy due to the optimization of thousands of control variables. These variables are frequently interdependent and have non-linear correlations with FEL performance, which makes optimization of such a complex system challenging, particularly for soft XFEL. Additionally, FEL inherently suffers from shot-to-shot intensity jitter, which necessitates online optimization in the presence of strong noise. In this study, we report the results of our experiments using an evolutionary strategy algorithm to enhance FEL intensity despite large intensity jitter.
THPS078
Measuring single-pass dispersion in the LHC
3121
During the LHC Ion Run in 2023, the ALICE detector observed a high level of background that prevented efficient data taking. This background was caused by different ion species generated in the betatronic collimation region that were intercepted by the Tertiary collimator near ALICE Interaction Point. The mass-to-charge ratio of these generated ions causes them to follow a different trajectory to the main ion beam, similar to off momentum particles. Since this is a single-pass effect, the closed dispersion does not describe the trajectory of these ions. Instead, the single-pass or one-pass dispersion is the relevant quantity to measure. In this paper two methods for reconstructing the single-pass dispersion based on the closed orbit and optics data are described. The methods are validated through simulations and applied to real data from the LHC 2023 Ion Run.
Paper: THPS078
DOI: reference for this paper: 10.18429/JACoW-IPAC25-THPS078
About: Received: 27 May 2025 — Revised: 04 Jun 2025 — Accepted: 04 Jun 2025 — Issue date: 08 Sep 2025
THPS079
First prototype measurements with an electro-optical bunch profile monitor for FCC-ee
3125
The future circular electron-positron collider (FCC-ee) is designed for highest luminosity to enhance the precision of high-energy particle physics experiments, spanning energies from the Z pole to the $\text{t}\bar{\text{t}}$ threshold. As outlined in its conceptual design report, high-precision measurements of the longitudinal bunch profile are required across multiple operation modes, which presents key challenges for beam instrumentation. As part of the feasibility study, a concept for an electro-optical (EO) bunch profile monitor has been developed to address these challenges, building on the existing EO beam diagnostic at the Karlsruhe Research Accelerator (KARA) at KIT. The first EO monitor prototype for FCC-ee features a novel crystal-holder design using prisms, enabling a single-pass setup crucial for measuring the long bunches during Z operation. This contribution presents the first measurement results of the EO monitor prototype for FCC-ee, which were obtained in the in-air test stand at the CERN Linear Electron Accelerator for Research (CLEAR).
Paper: THPS079
DOI: reference for this paper: 10.18429/JACoW-IPAC25-THPS079
About: Received: 28 May 2025 — Revised: 03 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 08 Sep 2025
THPS082
Impact of beam background and jitter on LUXE interaction point
3129
LUXE is an international project that aims to study Quantum Electro-Dynamics processes that occur in the strong field regime. Using the electron beam from the European XFEL, this experiment will perform electron-laser and photon-laser collisions. Beamline simulations are required to understand what beam properties and backgrounds are expected at key locations. The beam optics was design and simulated with MAD-8 and this used to create a BDSIM simulation. To perform high precision interactions it is crucial that the transverse size and position of the electron beam can be measured. The variation of the beam position over time also has impacts on an efficient collision with the laser. This study uses simulated virtual measurement, wire scanning methods, and real measurements at the XFEL to evaluate those parameters. Finally, background from both the upstream beam line and the different dumps must be estimated to ensure that the impacts on the experiment are low enough. This paper present BDSIM simulations with high statistics necessary to evaluate the background. Critical for BDSIM studies is finding optimised ways to do cross-section biasing and final state splitting in the dumps.
Paper: THPS082
DOI: reference for this paper: 10.18429/JACoW-IPAC25-THPS082
About: Received: 27 May 2025 — Revised: 04 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 08 Sep 2025
THPS083
Investigating beam-induced electron emission from thin wires in PSI proton beams
3133
The emission of electrons induced by beam interaction with thin targets is a phenomenon used to measure various properties of particle beams. The main processes of electron emission are: secondary emission, delta electron production and thermionic emission. The last one is not desired, because the intensity of thermionic electrons is not directly related to beam density profile. A common technique to suppress thermionic emission employs bias potential on the wire, which allows for recapturing of low energy electrons. This study investigates the effectiveness of the bias voltage method for high-brightness proton beams of the HIPA accelerator. Through experiments and simulations, the study aims to better understand the emission spectra, the suppression of thermionic emission, and the effects of beam fields on electron dynamics.
Paper: THPS083
DOI: reference for this paper: 10.18429/JACoW-IPAC25-THPS083
About: Received: 28 May 2025 — Revised: 04 Jun 2025 — Accepted: 04 Jun 2025 — Issue date: 08 Sep 2025
THPS084
LHC BLM-based beam loss pattern recognition algorithm for off-momentum losses
3137
The Beam Loss Monitoring System (BLM) of the Large Hadron Collider (LHC) protects the accelerator against energy deposition from beam losses. One of the most critical moments regarding beam losses is the start of the beam acceleration. During this process, particles outside the bucket will not be captured in the first seconds of the start of ramp thus being lost at the machine aperture. This is expected to be the moment of minimum beam lifetime in the LHC cycle. During Run 3, losses from these off-momentum particles triggered some beam dumps. Several studies are on-going to assess a possible limitation from this loss scenario. This contribution quantifies the beam power lost at that moment and how the losses are distributed along the accelerator by the use of a dedicated BLM loss pattern recognition algorithm.
Paper: THPS084
DOI: reference for this paper: 10.18429/JACoW-IPAC25-THPS084
About: Received: 28 May 2025 — Revised: 31 May 2025 — Accepted: 01 Jun 2025 — Issue date: 08 Sep 2025
THPS087
Raspberry Pi cameras for beam diagnostics at the Frankfurt Neutron Source
3141
The application of Raspberry Pi cameras as cost-effective, versatile beam diagnostic tools is currently being explored at the Frankfurt Neutron Source (FRANZ). These compact imaging systems have been deployed to investigate proton beams at energies of 60 keV and 700 keV, including configurations where cameras are installed both externally and directly inside the accelerator’s RF resonator. Such setups provide opportunities to visualize beam profiles and related phenomena, potentially offering new insights into beam dynamics and cavity conditioning. This contribution will present the latest developments in camera integration, image acquisition, and preliminary image analysis techniques. By showcasing ongoing work and recent findings, we aim to highlight the potential of this approach for enhancing beam diagnostics in future accelerator environments.
Paper: THPS087
DOI: reference for this paper: 10.18429/JACoW-IPAC25-THPS087
About: Received: 28 May 2025 — Revised: 01 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 08 Sep 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-IPAC25-THPS089
About: Received: 28 May 2025 — Revised: 03 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 08 Sep 2025
The contribution of multiple reflections to transition radiation
A uniformly moving electron passing through a slab induces electromagnetic emission known as transition radiation. The generated rays propagate inside the slab and undergo multiple reflections off the slab boundary. We employ the polarization current method in order to derive the reflectionless solution for an observed radiation intensity and compare it with that of Pafomov which accounts for multiple reflections exactly. We identify the parameters of the set up that reduce the Pafomov solution to a reflectionless scenario. Provided the ultrarelativistic electron, the proper choice of the slab thickness allows the consideration of the reflectionless solution even in the optical range. Furthermore, it is shown that in the x-ray regime the reflections only become substantial when the radiation is incident on the slab boundary at a high angle at which the intensity of the radiation is vastly reduced. Therefore for a slab shaped screen the reflections may be ignored. Nevertheless the identification of the scenarios where reflectionless solution deviates from the Pafomov, could be used to qualitatively describe transition radiation from targets of complex shape.
THPS091
Beam instrumentation at the multi-turn linac passages of MESA
3148
We will present the status of the beam instrumentation at MESA. To put MESA into operation various diagnostic systems are necessary. To optimize the beam the position and phase with respect to the accelerating RF needs to be optimized to be able to recirculate the beam for multi-turn operation or ERL mode respectively. On the other hand, an absolute beam current measurement is necessary. This can be achieved with a DCCT on the linac axis. The instrumentation will be installed very close to our cryo modules and needs to fulfil the excellent vacuum requirements for superconducting RF.
Paper: THPS091
DOI: reference for this paper: 10.18429/JACoW-IPAC25-THPS091
About: Received: 28 May 2025 — Revised: 03 Jun 2025 — Accepted: 04 Jun 2025 — Issue date: 08 Sep 2025
THPS093
Multichannel system for measuring the phase of acceleration and other parameters of beams in a cyclotron
3151
Diagnostics of charged particle beams is an important area in the field of accelerator technology. Non-destructive methods of beam diagnostics are becoming increasingly popular, as they allow measurements to be taken without changing the beam parameters. This is particularly valuable when studying continuous processes, the results of which can be distorted when using traditional diagnostic methods. Pickup electrodes are devices used for non-destructive diagnostics of charged particle beams. They are thin metal plates located along the axis of the beam motion. When a particle beam passes near a pickup electrode, it creates an electrical signal that is proportional to the beam current. This signal can be processed and analyzed using special equipment and software. A multichannel modular system with expandability has been developed to measure particle acceleration parameters, specifically the phase distribution during movement in the accelerator chamber, coordinates relative to the median plane and other parameters. The paper presents the results of testing the system at the DC-280 cyclotron at FLNR JINR and SSC at IThemba LABS.
Paper: THPS093
DOI: reference for this paper: 10.18429/JACoW-IPAC25-THPS093
About: Received: 27 May 2025 — Revised: 02 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 08 Sep 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-IPAC25-THPS094
About: Received: 28 May 2025 — Revised: 03 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 08 Sep 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-IPAC25-THPS095
About: Received: 28 May 2025 — Revised: 31 May 2025 — Accepted: 05 Jun 2025 — Issue date: 08 Sep 2025
THPS097
Minimizing disturbance in ion beam profiling with PEPITES monitor
3162
In the field of beam diagnostics for radiotherapy, accurate dose delivery relies on ultra-thin, linear and radioresistant monitors to minimize beam scattering and achieve precise profiling. The first PEPITES prototype monitor features two segmented cathodes, each paired with a high-voltage-biased anode. This latter effectively captures secondary electrons generated by the cathodes when they interact with the beam, enabling the detection of a measurable signal. The Water Equivalent Thickness (WET) of this design is approximately 10 μm*. To achieve efficient profiling of the charged particle beam when the monitor is positioned several meters upstream of the patient, we developed a thinner design. This configuration features two anodes positioned outside the beam path, reducing by half the amount of material that interacts with the beam, thereby minimizing beam disturbances. Both, the previous and the updated PEPITES monitor designs were recently tested at CNAO,Italy. Measurements were successfully conducted using a 115 MeV carbon ion beam at varying high-voltage power. These results will be presented and compared to demonstrate the enhanced efficiency of the upgraded PEPITES version.
Paper: THPS097
DOI: reference for this paper: 10.18429/JACoW-IPAC25-THPS097
About: Received: 01 Jun 2025 — Revised: 02 Jun 2025 — Accepted: 04 Jun 2025 — Issue date: 08 Sep 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-IPAC25-THPS098
About: Received: 28 May 2025 — Revised: 04 Jun 2025 — Accepted: 04 Jun 2025 — Issue date: 08 Sep 2025
Longitudinal phase space measurement using a corrugated structure at the PAL-XFEL
We present the experimental results of the longitudinal phase space (LPS) measurement using a corrugated structure at Pohang Accelerator Laboratory X-ray Free-Electron Laser (PAL-XFEL). The electron beam, passing the corrugated structure, generates the wakefield, which streaks the beam horizontally. The dipole magnet following the corrugated structure disperses the streaked beam vertically. By analyzing the transverse distribution observed at the screen monitor after those components, the electron beam LPS can be characterized. The LPS after the FEL process can also provide the FEL temporal profile, which is the valuable information for the accelerator optimization as well as the user experiments. In this paper, we present the preliminary experimental results for the characterization of the electron beam LPS and FEL profile.
Advancements in RadiaBeam’s multi-dimensional bunch shape monitor: updated testing results and improvements
The Bunch Shape Monitor (BSM) is a versatile diagnostic device designed to measure longitudinal beam parameters, which are essential for the operation and development of high-intensity linear accelerators. However, these measurements remain challenging for proton and ion beams at non-relativistic energies. RadiaBeam has developed an enhanced BSM prototype with several key innovations to improve performance. These include a focusing field between the wire and entrance slit for improved collection efficiency, a redesigned microwave deflector for enhanced beam linearity, and a moving mechanism enabling both transverse profile and longitudinal measurements. Following the initial tests at the Spallation Neutron Source (SNS) presented last year, this work details updated testing results including characterization and optimization, and additional component improvements based on the beam tests conducted at the SNS facility.
THPS103
Optical electron beam diagnostics at the Novosibirsk FEL
3170
We present an overview of recent and upcoming enhancements to the optical electron beam diagnostics stations at the Novosibirsk Free Electron Laser (FEL) facility. These diagnostic stations are designed to measure key beam parameters, including beam energy spread, length and emittance, at the third FEL of Novosibirsk FEL. Currently, the stations for measuring electron beam energy spread and undulator radiation spectrum are in the commissioning phase, with initial results already obtained. The new optical diagnostics are essential for the precise tuning of the magnet system used in electron outcoupling experiments. This paper provides a comprehensive overview of the new diagnostic systems, discusses the preliminary measurement results of beam parameters, and outlines the experiments planned for the near future.
Paper: THPS103
DOI: reference for this paper: 10.18429/JACoW-IPAC25-THPS103
About: Received: 28 May 2025 — Revised: 03 Jun 2025 — Accepted: 04 Jun 2025 — Issue date: 08 Sep 2025
THPS104
Development and testing of an autocorrelator for measuring the duration of picosecond pulses of near infrared radiation
3174
The paper presents a design of an autocorrelator manufactured to measure the duration of infrared picosecond pulses of radiation from the 3rd laser of the Novosibirsk Free Electron Laser facility, as well as the results of testing the autocorrelator when measuring the duration of picosecond pulses in the visible range. The results and future plans for future experiments using developed autocorrelator
Paper: THPS104
DOI: reference for this paper: 10.18429/JACoW-IPAC25-THPS104
About: Received: 28 May 2025 — Revised: 03 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 08 Sep 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-IPAC25-THPS105
About: Received: 26 May 2025 — Revised: 02 Jun 2025 — Accepted: 03 Jun 2025 — Issue date: 08 Sep 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-IPAC25-THPS107
About: Received: 28 May 2025 — Revised: 31 May 2025 — Accepted: 03 Jun 2025 — Issue date: 08 Sep 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-IPAC25-THPS108
About: Received: 28 May 2025 — Revised: 04 Jun 2025 — Accepted: 04 Jun 2025 — Issue date: 08 Sep 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-IPAC25-THPS109
About: Received: 06 Jun 2025 — Revised: 14 Jun 2025 — Accepted: 14 Jun 2025 — Issue date: 08 Sep 2025
THPS110
Advancing accelerator science through data-intensive research and training
3193
The Liverpool Centre for Doctoral Training in Innovation in Data Intensive Science (LIV.INNO) has made significant progress in applying data-intensive methods to accelerator research. This contribution presents research outcomes from the center with a focus on two key projects. The first focuses on optimizing 3D imaging for medical and industrial applications, integrating Monte Carlo simulations and advanced collimation techniques to enhance low-dose, portable X-ray systems, with implications for wider accelerator diagnostics. The second lever-ages deep learning models to reconstruct transverse beam distributions at CERN, addressing challenges in image distortion from multimode optical fibers under high-radiation conditions. The results are connected with wider progress made in machine learning and artificial intelligence for particle accelerators. Furthermore, the paper summarizes the outcomes of several key LIV.INNO events: the STFC Summer School on Data Intensive Science, the LIV.INNO 2024 Industry Showcase and the 2025 AI for Innovation Summit.
Paper: THPS110
DOI: reference for this paper: 10.18429/JACoW-IPAC25-THPS110
About: Received: 28 May 2025 — Revised: 31 May 2025 — Accepted: 05 Jun 2025 — Issue date: 08 Sep 2025
Beam profile monitor using thin gas sheets
Transverse beam profile diagnostics for high intensity beams are very challenging as material inserts are untenable. An alternative single shot beam diagnostic was studied, and developed, that consists of a thin sheet of gas. When a charged particle beam traverses the gas sheet, the neutral particles are ionized. The ionization products are then imaged on a monitor and the time of flight is recorded. Based on the specific ionization mechanism at play, the transverse beam profile of the beam can be reconstructed. An experiment at low beam energy was performed at UCLA, and demonstrated the basic concept for impact ionization. Future steps include demonstrating the concept for higher intensity beams as well as technical system modifications to improve the utility in large scale facilities.
An effective method for crossbar-switch interference suppression based on WPT in beam position measurements of HLS II
There are 32 electron beam position processors used for beam position measurement in the storage ring of Hefei Light Source(HLS II), the crossbar-switch(CS) of processors must be operation for RF channels compensation and long-term stability. The turn-by-turn(TBT) and fast acquisition(FA) beam position signals would suffer from the CS interference like harmonics and artifact when the CS is operation. In this paper, an effective method based on wavelet packet transform(WPT) is proposed to suppress the CS interference without distorting actual TBT and FA signal. This method starts with the wavelet packet decomposition of the contaminated TBT signal first, then wavelet coefficients are further processed, and finally the processed coefficients of whole subbands are reconstructed through filter banks to obtain the clean TBT signal. As a result, the relatively slow rate of clean and undistorted fast acquisition(FA) signal is obtained through partial reconstruction. Experiment results with real TBT signals demonstrate the effectiveness of the proposed method, and also show that the proposed method does not distort the actual TBT and FA signal while suppressing the CS interference.
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-IPAC25-THPS113
About: Received: 28 May 2025 — Revised: 04 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 08 Sep 2025
THPS115
MNDACS – Mesh networked data acquisition and control system
3200
At our institute, we needed a scalable SCADA system for both FRANZ and smaller laboratory test setups. Given the heterogeneity of devices, the system had to be easily extendable to support custom-built hardware, self-made devices, and standard PLC systems. Additional requirements included low maintenance, minimal system demands, and compatibility with various IT environments, operating systems, and hardware architectures. To meet these needs, we developed a ZeroMQ pub/sub pattern-based system in Java, which can function as a standalone instance or as a distributed mesh network across multiple systems. A modular device driver design simplifies the integration of devices with existing control software components. A universal XML-based driver enables device communication descriptions without the need for programming or recompilation. To minimize system resource demands, a Swing-based GUI was incorporated. This GUI is configurable via XML files, providing user flexibility and reducing the programming effort required for standard or predefined elements.
Paper: THPS115
DOI: reference for this paper: 10.18429/JACoW-IPAC25-THPS115
About: Received: 26 May 2025 — Revised: 03 Jun 2025 — Accepted: 03 Jun 2025 — Issue date: 08 Sep 2025
THPS116
A hybrid LINAC low level RF control system for FRANZ
3203
The FRANZ linac, consisting of a coupled RFQ-IH cavity and a subsequent CH rebuncher, requires an LLRF system with moderate performance demands. These include amplitude control to maintain a constant field in the cavity, constant phase synchronization between the accelerator and rebuncher, and plunger control to stabilize the cavities frequency at 175 MHz. Given the dead time from LLRF RF output to probe input is approximately 150 ns and the system operates in cw or 1 ms pulsed mode, a decision was made to design a system with a reaction time of 1 µs. To ensure flexibility, the system was designed with digital control. Consequently, an analog-digital hybrid system was implemented. The RF signal processing is performed using classical analog components, while the control and readout of the analog signals are managed by a ZYNQ SoC, which combines FPGA and ARM processors. The first proof-of-concept prototype for amplitude control, including reflection and vacuum monitoring, has been successfully operational with the RFQ since late 2023. Development of the next version, which will include phase and plunger control, is underway and is expected to undergo beam testing in 2025.
Paper: THPS116
DOI: reference for this paper: 10.18429/JACoW-IPAC25-THPS116
About: Received: 26 May 2025 — Revised: 03 Jun 2025 — Accepted: 03 Jun 2025 — Issue date: 08 Sep 2025
Genetic algorithm code for real-time optimization in the STAR thomson back-scattering source
The STAR facility represents an advanced high-energy photon source located at the University of Calabria (Italy). It was conceived to generate high-energy photons through the inverse Thomson scattering process. Following a recent upgrade, the facility features an additional beamline driving the source from 65 MeV electron beam energy up to 140 MeV, leading to a maximum photon energy of 350 keV. The control system based on the EPICS framework is central to STAR's operation. Optimizing the machine's performance requires advanced methodologies capable of managing its non-linear dynamics. Artificial intelligence, particularly Genetic Algorithms, has emerged as a powerful tool for achieving real-time optimization. The software GIOTTO, a GA-based optimization framework, will be set to redefine STAR's beamline operations by dynamically tuning machine parameters to enhance radiation production and beam quality. By driving the ASTRA simulation code as a stand-in for the real machine, we are actively testing GIOTTO's capabilities in a controlled environment. The full integration of GIOTTO into STAR's control system promises to improve the machine and beam dynamics optimization processes.
THPS120
Considerations for the transverse feedback system for the CERN FCC-ee collider ring
3206
The FCC-ee, a 90.7 km circumference e+ and e- collider under study at CERN, will require a transverse feedback system capable of handling risetimes as fast as four turns for the lowest order coupled-bunch modes. This can be realized by a distributed system of pick-ups and kickers in more than one location of the ring. The advantages are weighed with respect to the flexibility to respond to different choices of transverse tune working points and the possibility to operate the transverse kickers as an exciter for several measurement applications including as a depolarizer for energy calibration at Z and W energies. Options for the signal processing are outlined together with the overall specifications for the system components. The choice of frequency, a multiple of 40 MHz, is determined by requirements of the baseline 25 ns bunch spacing and the desire for a power efficient kicker system favoring stripline kickers. Performance of different variants of the system are compared in simulation and evaluated for added flexibility and complexity with respect to the placement in the ring.
Paper: THPS120
DOI: reference for this paper: 10.18429/JACoW-IPAC25-THPS120
About: Received: 28 May 2025 — Revised: 04 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 08 Sep 2025
THPS122
FGC Test Manager: A framework for executing and monitoring software tests
3210
Function Generator Controllers (FGCs) are key devices used in CERN’s converter control systems to regulate and monitor the power converters that supply current to the magnets in the accelerator complex. To ensure the reliability and enhance the quality assurance of the software that controls these devices, the FGC Test Manager has been developed. It encompasses the Python library pyfgc_test_framework, which provides an interface for test scripts to seamlessly communicate with the FGC devices; and a web tool providing an interface to run test scripts on schedule and on demand, assign tests to resources, review test results, and directly access test logs. The web tool uses Vue 3 for the frontend and FastAPI with a PostgreSQL database for the backend. Test execution is handled by the GitLab Pipeline API, which executes pipelines directly in the repository containing the tests. This paper presents the design and functionality of the FGC Test Manager and the improvements it brings to the quality assurance of CERN's converter control systems.
Paper: THPS122
DOI: reference for this paper: 10.18429/JACoW-IPAC25-THPS122
About: Received: 23 May 2025 — Revised: 03 Jun 2025 — Accepted: 04 Jun 2025 — Issue date: 08 Sep 2025
THPS124
Modernization of the automated radiation monitoring system for the U400M cyclotron and the main building at FLNR
3213
Currently, the Flerov Laboratory of Nuclear Reactions (FLNR) is modernizing its accelerator complex, focusing on the development of new facilities and the enhancement of existing ones. Notably, the U400M cyclotron has been successfully modernized. As part of the upgrade of the U400M's main systems, a project for the deep modernization of its Automated Radiation Monitoring System (ARMS) was initiated. In addition to monitoring the radiation environment of the U400M, the ARMS oversees other radiation-related facilities in the main building at FLNR. These include the MT-25 microtron, radiochemical laboratories of the 2nd and 3rd safety classes, and the radioactive isotope storage facility. This report presents the main types of radiation monitoring implemented by the system, the equipment used, its software features, and the interaction algorithms with the control systems of the U400M and MT-25 accelerators, as well as the U400M Interlock and Signalization System (ISS). Additionally, the current status of the project, challenges in its commissioning, and the prospects for further development of the system at FLNR are discussed.
Paper: THPS124
DOI: reference for this paper: 10.18429/JACoW-IPAC25-THPS124
About: Received: 22 May 2025 — Revised: 02 Jun 2025 — Accepted: 03 Jun 2025 — Issue date: 08 Sep 2025
THPS125
Design and development of AR RF personnel protection and interlock system for RF Test with Access mode to RF cavities in ALS-U project at LBNL
3216
The ALS-U project at LBNL is a major upgrade of the ALS involving a new Accumulator Ring (AR) and an upgraded Storage Ring (SR). The new AR RF System has one operational mode with beam and three test modes without beam. Another upgraded overarching Ring Personnel Protection Systems (PPS) covering both AR and SR ring enclosure areas is in place for personnel protection from ionizing radiation during beam operation and it is interfaced with AR RF PPS subsystem for status & control signals. In the RF Test with Access mode, the controlled access of authorized personnel is permitted to AR RF cavities area when it is powered below certain predetermined power limit without beam, for conducting low power RF leakage checks, tests. For that objective, an AR RF PPS power monitor & interlocks as described in this paper has been designed & developed for use in the Test with Access mode in order to ensure that potential exposure to harmful ionizing X-rays from RF cavity operating does not result in doses above the prescribed limits. The actual X ray dose rate data will also be experimentally surveyed at various RF cavity power levels. This paper presents the design features, circuits and construction of such AR RF PPS subsystem for accurately monitoring RF Cavity power and to break the interlocked chain to turn OFF the RF input drive to AR RF High Power Amplifiers (HPA) feeding RF cavities, if the RF cavity power exceeds such pre-determined power limits.
Paper: THPS125
DOI: reference for this paper: 10.18429/JACoW-IPAC25-THPS125
About: Received: 27 May 2025 — Revised: 02 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 08 Sep 2025
Impact of beam energy increase on the dose rates in and around SNS service bay
The Spallation Neutron Source (SNS) at Oak Ridge National Laboratory (ORNL) is an accelerator-based neutron source facility that provides the most intense pulsed neutron beams in the world for scientific research and industrial development. The neutron production occurs when a horizontally injected proton beam strikes the liquid mercury target placed in the center of the target monolith. The mercury target has a finite lifespan due to radiation and cavitation damage, and therefore is mounted on a carriage that can be retracted for replacement into the target service bay located at the back of the target monolith. The Proton Power Upgrade Project (PPU), which will double the accelerator power capability from 1.4 to 2.8 MW and will increase the proton beam energy from 1 GeV to 1.3 GeV, is completed. To evaluate the impact of the proton energy increase on radiation safety, neutronics studies are performed to characterize the dose rates inside and outside the SNS service bay. Studies are conducted for the incoming proton beam at 1 GeV and 1.3 GeV.Analyses of the dose rates show thatvthe target service bay shielding works adequately providing dose rates below facility limits.
THPS127
Design of RF duct shielding for the SPS-II 3-GeV electron storage ring
3219
The Siam Photon Source II (SPS-II) is a fourth-generation synchrotron light source designed to provide high-brightness, low-emittance, high-energy electron beams for advanced synchrotron applications. SPS-II is equipped with a 150-MeV linear accelerator, a 3-GeV booster synchrotron, and a 3-GeV electron storage ring, enabling the production of high-quality synchrotron radiation for a wide range of scientific research fields. The 500 MHz RF system in the storage ring serves to replenish the energy lost by electrons due to synchrotron radiation. RF cavities generate oscillating electromagnetic fields at a specific frequency, accelerating the electrons each time they pass through the cavity. The RF ducts house the waveguides and transfer RF power to the RF cavities inside the storage ring tunnel. However, penetration in the storage ring tunnel may allow radiation within the shielding tunnel to leak outside the shielding. For this reason, the design of the RF ducts must be carefully considered. The FLUKA particle transport code is used to investigate the shielding. The results indicate that the radiation dose is below the design criterion, meeting the radiation safety standards.
Paper: THPS127
DOI: reference for this paper: 10.18429/JACoW-IPAC25-THPS127
About: Received: 27 May 2025 — Revised: 30 May 2025 — Accepted: 30 May 2025 — Issue date: 08 Sep 2025
Uncertainty in Harshaw 6600 dosimeters: a study of routine dosimeter services at Nepal Academy of Science and Technology
This research investigates the uncertainty in radiation dose measurements utilizing TLD-100 Dosemeters (LiF:Mg, Ti), and a TLD Reader System of Harshaw 6600 Plus present at Nepal Academy of Science and Technology. The calibration of the Dosemeter reader facilitated precise dose determination, resulting in mean calibration and correction factors of 1.052 and 0.003, respectively. Particularly at low effective dose levels, the study underscores the inevitability of heightened uncertainties across all radiation characteristics. An evaluation of uncertainty uncovered various contributing sources, including detector sensitivity inhomogeneity, reading variability, and energy/angular dependence, with a mean uncertainty estimated at 0.25% and overall uncertainty 19.16% for K=1. Additionally, luminescence and angular dependence studies under different irradiation conditions, with angular response factors ranging from 0.90 to 1.10. Also, Klein-Nishina differential cross-section was study at different energy (60 keV, 80 keV, 100 keV and 150 keV) with scattering angle considering LiF:Mg, Ti as target and found decrease with scattering angle.
Early prediction of system failures at Los Alamos Nuclear Science Center
Accelerators are complex systems composed of tens of thousands of individual components requiring continuous maintenance. Aging facilities such as LANSCE face an increased rate of equipment failures, resulting in costly unscheduled shutdowns for maintenance. Early identification and localization of problems along the accelerator can mitigate future failures during scheduled maintenance periods rather than emergency shutdowns. This approach will significantly enhance the facility's reliability and increase beam availability for users. We have developed a mathematical formalism to analyze all available data for a LANSCE subsystem and generate signals indicating abnormal operation. The system accounts for hidden internal correlations between various parameters. This predicted deviation from the norm is supported by historical records in log files. We report progress on developing an anomaly detection system for LANSCE by expanding predictions to all subsystems, increase LANSCE's data archiving capability by an order of magnitude, and developing algorithms to provide operators with signals indicating developing abnormalities and pinpointing problematic beamline elements.
Development of low-level RF control system for Injector of Hefei Advanced Light Facility project
Hefei Advanced Light Facility (HALF) is a fourth-generation synchrotron radiation source based on diffraction limited storage ring. It comprises a 180-meter injector and a 480-meter storage ring. The injector incorporates a digital low-level radio frequency (LLRF) control system based on MTCA.4, ensuring a stable and adjustable microwave field for the acceleration structure. This article outlines the structure of the LLRF system, encompassing both hardware and software components. Within the software, we have mitigated signal drift induced by environmental temperature fluctuations by adding a reference tracking module. Building upon the existing IQ closed-loop functionality, we have successfully implemented separate amplitude and phase closed-loop functions. In high-power online testing, the IQ closed-loop demonstrated amplitude and phase stabilities of 0.0411% (RMS)/0.0638° (RMS), respectively. Furthermore, the phase stability achieved by the phase-independent closed-loop function reached 0.0646° (RMS). Currently, the LLRF system has fulfilled the design requirements of HALF.
Advancements on bunch profile measurement of the operational H- beam at the SNS linac usinglaser wire
A laser-wire-based method for a direct measurement of bunch profiles of an operational H- beam has been developed at the SNS. In this talk, we report recent advancements on the bunch profile measurements using a customized picosecond pulsed laser with giga-watt peak power and a user-defined macro-pulse structure. The modified system enables fast and precise tracking of the bunch profiles over both the longitudinal and transverse dimensions of the H- beam at different energy levels. The measurement results on the 1.7-MW neutron production beam at the completion of the recent Proton Power Upgrade (PPU) project will be described.
THPS133
Development of a 500 MHz direct RF sampling low-level RF system for ALBA and ALBA-II
3222
ALBA Low-Level RF (LLRF) system has provided over a decade of reliable operation and has been adopted by other synchrotron facilities. To meet the evolving requirements of ALBA and ALBA-II, a new LLRF system has been developed. This system features FPGA and ADC/DAC MTCA boards designed by SAFRAN, enabling direct 500 MHz signal sampling without down/up-conversion. These enhancements reduce system complexity, minimize noise, and simplify maintenance. SAFRAN also supplies peripheral modules and the Tango device server generator, while ALBA implemented it and developed a new GUI. Upgraded GPIO and RF signal patch panels complement the new hardware. The legacy VHDL code has been updated to improve readability and functionality, incorporating advanced features such as octant selection and a harmonic direct feedback selection method. The latter, based on IIR filtering, isolates positive and negative revolution harmonics in the I/Q domain, feeding them back to amplifiers to effectively mitigate transient beam loading caused by the storage ring bunch train gaps. This upgraded LLRF system delivers enhanced performance and greater flexibility to address the future needs of ALBA and ALBA-II.
Paper: THPS133
DOI: reference for this paper: 10.18429/JACoW-IPAC25-THPS133
About: Received: 28 May 2025 — Revised: 31 May 2025 — Accepted: 04 Jun 2025 — Issue date: 08 Sep 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-IPAC25-THPS134
About: Received: 28 May 2025 — Revised: 01 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 08 Sep 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-IPAC25-THPS135
About: Received: 27 May 2025 — Revised: 03 Jun 2025 — Accepted: 04 Jun 2025 — Issue date: 08 Sep 2025
A versatile low level RF controller design for FRIB and extended projects
The digital LLRF controller for the Facility for Rare Isotope (FRIB) project was designed to accommodate various cavity types with six distinct frequencies ranging from 40.25 to 322 MHz. The cavities also adopt different types of tuners, e.g. stepper motor, pneumatic, water flow, etc. A common hardware platform with design choices such as direct sampling of RF, compatible footprint for RF components (e.g. filters), same form factor PCBs, spare channels (RF, analog and digital) made it a reality. The design later turned out to be very adaptive to unforeseen new requirements as the project moved on. Those include adding an interface to enable and monitor the bias tee high voltage power supply, adding a serial interface to communicate with the tuner servo controller and monitoring a cold cathode gauge for faster interlock response. Most recently FRIB LLRF controller use case is expanded to support the testing of e-gun for the SLAC LCLS-II project which runs at a different RF frequency and uses a piezo tuner. Furthermore we are exploring a solution with this versatile platform to support the upgrade of the K500 cyclotron RF control with a continuous frequency range from 10 to 27 MHz.
THPS137
RF phase feedback at KEK e-/e+ Injector LINAC
3234
The KEK e-/e+ LINAC delivers the beams to four storage rings with the top-up injections by switching the beam mode in 50 Hz repetition rate. The beam charge, energy, and number of bunches (one or two) are different for each ring. Therefore, the RF timing and phase are adjusted to each beam mode independently. To stabilize the RF phase drifts caused by the klystron high voltage, the cooling water and accelerating structure temperature, the RF phase feedback was introduced. The correction phase quantity is obtained by feedback calculation using non-injection mode without beam acceleration, and the value is added to set phase value in each mode. As a result, the RF phase in each beam mode has been stabilized.
Paper: THPS137
DOI: reference for this paper: 10.18429/JACoW-IPAC25-THPS137
About: Received: 04 Jun 2025 — Revised: 05 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 08 Sep 2025
Advanced optimization of microwave signal stability in the X band unit of SXFEL injector
In the SXFEL injector, the beam stability achieved superior performance, maintaining fluctuations below 0.01% after passing through four S-band accelerating units. However, the stability deteriorated to 0.02% upon exiting the X-band linearizer. To mitigate this degradation, a series of targeted enhancements were implemented, including an extensive upgrade of the low-level RF system’s front-end electronics and the integration of adaptive modulation techniques for input signal optimization. These measures effectively restored and improved the beam stability, achieving precision levels within 0.01%.
FPGA-based multi-precision RF waveform measurement
RF measurements are crucial for stabilizing the power source output and extracting beam data. As digital systems evolve, the analog-to-digital converter (ADC) now commonly reaches 16 bits and 100 MHz, enabling multi-channel low-level radio frequency (LLRF) systems to generate several gigabytes of data per second, overwhelming data storage and processing capabilities. This paper proposes a pre-processing method using Field Programmable Gate Arrays (FPGAs), which dynamically adjusts timing intervals based on operator requirements. For detailed waveform analysis, the LLRF can upload data over short time intervals with high precision. Conversely, for applications concerned with slow drift, long-time-range, low-precision data is transmitted. Thus, the total amount of uploaded data remains constant. A multi-order filter is applied to the raw data, with desired precision achieved at specific orders. The time precision ranges from 10 ns to 20 µs, while the time range spans from 20 µs to 40 ms.
THPS140
High precision RF pulse shaping with direct RF sampling for future linear accelerators
3237
In various of particle accelerator designs, amplitude and phase modulation methods are commonly applied to shape the RF pulses for implementing pulse compressors or compensating for the fluctuations introduced by the high-power RF components and beam loading effects. The phase modulations are typically implemented with additional phase shifters that requires drive or control electronics. With our recent next generation LLRF (NG-LLRF) platform developed based on the direct RF sampling technology of RF system-on-chip (RFSoC) devices, the RF pulse shaping can be realized without the analogue phase shifters, which can significantly simplify the system architecture. We performed a range of high-power experiments in C-band for evaluating the RF pulse shaping capabilities of the NG-LLRF system at different stages of the RF circuits. In this paper, the high-power characterization results with the Cool Copper Collider structure driven by RF pulses with different modulation schemes will be described. With the pulse modulation and demodulation completely implemented in digital domain, the RF pulse shaping schemes can be rapidly adapted for X-band structures just by adding analogue mixers.
Paper: THPS140
DOI: reference for this paper: 10.18429/JACoW-IPAC25-THPS140
About: Received: 28 May 2025 — Revised: 03 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 08 Sep 2025
THPS141
Next generation LLRF control and monitoring system for S-band linear accelerators
3241
The low-level RF (LLRF) systems for S-band linear accelerating structures are typically implemented with heterodyne base architectures. We have developed and characterized the next generation LLRF (NG-LLRF) based on the RF system-on-chip (RFSoC) for C-band accelerating structures and the platform delivered the pulse-to-pulse fluctuation levels considerably better than the requirement of the targeted applications. The NG-LLRF system uses the direct RF sampling technique of the RFSoC, which significantly simplified the architecture compared with the conventional LLRF. We have extended the frequency range of the NG-LLRF to S-band and experimented with different RFSoC devices and system designs to meet the more stringent requirement for S-band LLRF applications. In this paper, the characterization results of the platform with different system architectures will be summarized and the high-power test results of the NG-LLRF with the S-band accelerating structure in the Next Linear Collider Test Accelerator (NLCTA) test facility at SLAC National Accelerator Laboratory will be presented and analyzed.
Paper: THPS141
DOI: reference for this paper: 10.18429/JACoW-IPAC25-THPS141
About: Received: 28 May 2025 — Revised: 04 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 08 Sep 2025