extraction
MOPM050
Combining quadrupole-driven slow extraction with RFKO at the CERN SPS
441
The CERN Super Proton Synchrotron (SPS) employs quadrupole-driven third-integer slow extraction to deliver beam to the North Area. This process is controlled by ramping all the magnets in the lattice, gradually driving the circulating beam into the tune resonance. In medical synchrotrons, Radio-Frequency Knock Out (RFKO) has proven to be a reliable alternative for driving the extraction process while maintaining good spill quality. Inspired by these efforts, a hybrid scheme was tested in the SPS, where a transverse exciter was used to apply a sinusoidal excitation in parallel with the magnetic ramp. It is demonstrated that this setup improves spill uniformity both in simulation and measurements.
Paper: MOPM050
DOI: reference for this paper: 10.18429/JACoW-IPAC25-MOPM050
About: Received: 26 May 2025 — Revised: 30 May 2025 — Accepted: 01 Jun 2025 — Issue date: 10 Jul 2025
MOPM051
Beam dump transfer line design in FCC-ee
445
The Future Circular lepton Collider (FCC-ee) will be an e+e- collider with beam energy spanning from 45.6 GeV to 182.5GeV. When operating in Z-mode, it will deliver the highest luminosity ever obtained in any lepton machine worldwide, and the stored beam energy will reach up to 18 MJ. Due to synchrotron radiation damping, the beam vertical size will be on the order of a few tens of um corresponding to a maximum energy density of ~5 GJ/mm^2 in the collider ring. A dedicated beam dumping scheme is required to safely dispose this potentially disruptive beam. A transfer line is designed to increase the beam transverse size as much as possible and reduce the energy density of the beam at the dump. This contribution presents the dump transfer line design for the collider ring as well as related studies on machine protection.
Paper: MOPM051
DOI: reference for this paper: 10.18429/JACoW-IPAC25-MOPM051
About: Received: 27 May 2025 — Revised: 04 Jun 2025 — Accepted: 04 Jun 2025 — Issue date: 10 Jul 2025
MOPM098
The mass production magnetic field measurement of the large aperture quadrupoles in HIAF
545
Currently the HIAF Project at IMP has reached the construction phase. The BRing is one of the key systems of HIAF, which is used to capture, accumulate, accelerate and extract the heavy ion beam injected by iLinac. The quadrupole magnets in BRing have large aperture (Ф260&Ф180) , large axial length(the total length of the magnet is reached 1140mm) and high integration field uniformity (±3×10-4). To measurement the magnetic field quality is very critical. The measurement aims to reach a reproducibility of 1.5×10-4 for the field integral, 2 ppm for the harmonic content for the main field and 0.2mm for the position of the magnetic center. A specially developed probe allows the simultaneous measurement of the field axis and quality. This thesis demonstrates that the system as it stands fulfils the high requirements with respect to the magnetic measurement and the magnetic center and thus provides the desired unique versatile equipment. The assessment was performed based on experimental results, direct calibration. The main defects treated are mechanical torsion and vibration of moving parts, electrical noise and power supply ripple.
Paper: MOPM098
DOI: reference for this paper: 10.18429/JACoW-IPAC25-MOPM098
About: Received: 28 May 2025 — Revised: 20 Jun 2025 — Accepted: 20 Jun 2025 — Issue date: 10 Jul 2025
MOPM107
Status of construction of the new heavy ion synchrotron SIS100 at FAIR
567
The construction of the new FAIR heavy ion accelerator facility at GSI is progressing well. With the start of installation of SIS100 an important new milestone in project execusion has been reached. SIS100 is the first superconducting, fast ramped synchrotron with special design features dedicated to the acceleration of high intensity, low charge state heavy ions. The full performance of the specific functional systems, stabilizing the dynamic vacuum at operation with high Uranium intensities in combination with high repetition rates, was recently demonstrated at the SIS100 string test. Even under the influence of eddy current heating of the chamber walls at high ramp rates, its separatly cooled cryogenic vacuum system assures a stabilization of the residual gas pressure at extremely low values. The first straight sectors and arc modules have been installed heading towards a first hardware commissioning in 2026.
Paper: MOPM107
DOI: reference for this paper: 10.18429/JACoW-IPAC25-MOPM107
About: Received: 01 Jun 2025 — Revised: 03 Jun 2025 — Accepted: 04 Jun 2025 — Issue date: 10 Jul 2025
MOPS007
Characterisation and mitigation of RF knockout
600
Beam stacking is a key advantage of Fixed Field alternating gradient Accelerators (FFAs) for high-intensity applications. During stacking, one beam is stored as a coasting beam at the extraction energy while another, incoming beam is accelerated. However, the beam loss mechanism termed RF knockout can occur during stacking and undermine gains in extracted beam current. The accelerating RF program of the incoming beam can cause cumulative displacements in the stored coasting beam and result in significant beam loss. To ensure that beam stacking is a viable technique to extract highest intensities from an FFA, methods to avoid the loss from RF knockout must be established. This study presents results from a series of experiments at the ISIS proton accelerator to characterise and, crucially, to mitigate RF knockout and ensure successful beam stacking with no loss.
Paper: MOPS007
DOI: reference for this paper: 10.18429/JACoW-IPAC25-MOPS007
About: Received: 27 May 2025 — Revised: 03 Jun 2025 — Accepted: 04 Jun 2025 — Issue date: 10 Jul 2025
MOPS051
Light upgrade of the ESRF booster
730
The ESRF booster has been built more than 30 years ago as injector of the first ESRF storage ring and it is still used to inject in the EBS. Several components of the booster have been updated in the years and it is now operated off-energy and with emittance exchange at extraction, however the lattice has not been modified since the '90s. A project to reduce the equilibrium emittance and bunch length of the booster by exchanging 18 quadrupole magnets has been proposed. In this paper we present the beam dynamics studies in presence of errors and the expected gain in injection efficiency.
Paper: MOPS051
DOI: reference for this paper: 10.18429/JACoW-IPAC25-MOPS051
About: Received: 28 May 2025 — Revised: 03 Jun 2025 — Accepted: 03 Jun 2025 — Issue date: 10 Jul 2025
MOPS092
Progress on beam dynamics studies for the ISRS isochronous ring spectrometer
793
A new lattice configuration is being developed for a compact,isochronous ring for the ISRS project, as an innovative spectrometer at HiE-ISOLDE. The design incorporates ten combined-function, canted cosine-theta (CCT) superconducting magnets, enabling the ring to fit within a constrained 5x5 meter hall space. This design presents significant challenges, particularly in accommodating the injection and extraction of a high beam rigidity beam, as the CCT magnets mechanical dimensions severely limit the space available for these subsystems. Using Bmad code simulations, the performance of beam injection and extraction, based on a high-field, superconducting septum and a fast magnetic kicker, is evaluated, along with the time-of-flight separation of various isotope ion products from selected nuclear reactions of interest.
Paper: MOPS092
DOI: reference for this paper: 10.18429/JACoW-IPAC25-MOPS092
About: Received: 09 May 2025 — Revised: 02 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 10 Jul 2025
MOPS126
Current status of conceptual horizontal splitter design for FFA@CEBAF energy Upgrade
810
Jefferson Lab’s Continuous Electron Beam Accelerator Facility (CEBAF) is currently investigating the feasibility of upgrading its maximum operating energy using Fixed-Field Alternating-gradient (FFA) recirculating arcs to increase the total number of recirculations of the beam through the pair of LINACs. These FFA arcs will be composed of permanent magnets, with small Panofsky-style multipole correctors. In order to control the beam parameters through these FFA arcs, horizontal splitters must be used. The geometrical and physical constraints, as well as the beam matching requirements are very restrictive, complicating the design. This work will show the current status of the most mature design, which includes matching solutions, as well as options for extraction of the beam.
Paper: MOPS126
DOI: reference for this paper: 10.18429/JACoW-IPAC25-MOPS126
About: Received: 27 May 2025 — Revised: 04 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 10 Jul 2025
TUCN3
Commissioning of the South African Isotope Facility
928
The South African Isotope Facility (SAIF) is a radioisotope production facility based around a 70 MeV Cyclotron from IBA. SAIF was commissioned at the end of 2023 and commenced commercial isotope production in 2024. The facility is located in three vaults at iThemba LABS in Cape Town. The vault design, radiation modelling, and an overview of construction are presented. The designs and commissioning of the cyclotron, beam lines, wobbler magnet, dedicated target stations and target transport system are described and discussed, along with their current performance.
Paper: TUCN3
DOI: reference for this paper: 10.18429/JACoW-IPAC25-TUCN3
About: Received: 28 May 2025 — Revised: 31 May 2025 — Accepted: 31 May 2025 — Issue date: 10 Jul 2025
TUPB002
Consideration for improving the longitudinal beam matching between RCS and MR at the J-PARC
932
The J-PARC 3 GeV Rapid-Cycling Synchrotron (RCS) delivers the high-intensity proton beam to the 30 GeV Main Ring (MR). The improvement of longitudinal beam matching between RCS and MR is desired to suppress the beam loss in the MR. A scenario to improve the longitudinal beam matching between RCS and MR is designed. For the RCS, the bunch lengthening scheme using the unstable fixed point generated by the second harmonic is considered. For the MR, the RF voltage pattern is adjusted to match the longitudinal beam emittance of the RCS. The details of the scenario for improving the longitudinal beam matching between RCS and MR and the results of beam simulation studies are reported.
Paper: TUPB002
DOI: reference for this paper: 10.18429/JACoW-IPAC25-TUPB002
About: Received: 26 May 2025 — Revised: 02 Jun 2025 — Accepted: 02 Jun 2025 — Issue date: 10 Jul 2025
TUPB003
Beyond 1 MW operation of the J-PARC RCS
936
Beyond 1 MW operation of the J-PARC RCS The 3-GeV Rapid Cycling Synchrotron (RCS) of the Japan Proton Accelerator Research Complex (J-PARC) has already been achieved the designed 1 MW operation to the Material and Life Science Experimental Facility (MLF). However, to cope with the gradually getting faster operation cycle of the main ring synchrotron sharing more beam requires RCS to accelerate more than 1 MW beam per pulse for the MLF to ensure net 1 MW beam power at the MLF. Moreover, the beam sharing to the under designed 2nd MLF target facility has also to be considered. As a result, the next goal is to realize 1.5 MW beam power first and continue for 2 MW or even more. This will be done by injecting more particles in the RCS by increasing both peak current and pulse duration of the injection beam. Beam dynamics issues and possible scenarios to realize far beyond 1 MW in the RCS are presented.
Paper: TUPB003
DOI: reference for this paper: 10.18429/JACoW-IPAC25-TUPB003
About: Received: 29 May 2025 — Revised: 02 Jun 2025 — Accepted: 04 Jun 2025 — Issue date: 10 Jul 2025
TUPB006
Readiness of the HEARTS@CERN facility for space electronics high-energy heavy-ion testing
948
The HEARTS@CERN activity in the framework of the HEARTS (High-Energy Accelerators for Radiation Testing and Shielding) EU project is targeted at enhancing Europe’s high-energy (>100 MeV/n) heavy ion electronics irradiation capability through the development of an irradiation beam combining unique penetration and ionization characteristics. These types of tests are essential for exploiting commercial electronics in space. Throughout 2024, the HEARTS@CERN efforts have focused on achieving and demonstrating compliance with the space user radiation effects testing requirements. This includes being able to offer a wide range of energies (and Linear Energy Transfer values) and fluxes, with a high level of accuracy and a rapid change between parameters. Moreover, large homogeneous beams are necessary for enabling the test of multiple electronic components in parallel, and for performing board level testing. This work will present requirements for high-energy heavy ion testing along with the level of compliance achieved, as demonstrated during the November 2024 HEARTS@CERN user run, with a focus on the beam related parameters, but including also facility and procedural considerations.
Paper: TUPB006
DOI: reference for this paper: 10.18429/JACoW-IPAC25-TUPB006
About: Received: 27 May 2025 — Revised: 03 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 10 Jul 2025
TUPB008
Spill optimization system improving slow extraction at GSI
956
Resonant slow extraction is routinely used to provide ion beams to various users. At GSI SIS18, two extraction methods are implemented: quadrupole-driven and Radio Frequency Knock Out (RF-KO) extraction. In either case, delivering a defined beam intensity (spill) without fluctuations or drifts is desired for an efficient beam usage. The Spill Optimization System (SOS) was developed to address this demand and improve the spill quality based on online spill monitoring. Developed using software-defined radio technology, it comprises a feedback controlling the spill rate and an optimization algorithm to improve the spill quality. In the case of RF-KO extraction, it controls the spill by generating tailored excitation signals for the KO exciter. For quadrupole-driven extraction, it produces a control signal for the tune ramp including tune wobbling to improve the spill quality. This contribution gives an overview on the systems and compares different usage scenarios.
Paper: TUPB008
DOI: reference for this paper: 10.18429/JACoW-IPAC25-TUPB008
About: Received: 26 May 2025 — Revised: 03 Jun 2025 — Accepted: 04 Jun 2025 — Issue date: 10 Jul 2025
TUPB009
The latest design for a future short-baseline neutrino beamline
960
The ENUBET and NuTAG projects propose the measurements of the $\nu_e$ and the $\nu_\mu$ cross sections at the relevant energies of Hyper-Kamiokande and DUNE. While ENUBET focuses on a fully instrumented decay tunnel to achieve a precise flux measurement, NuTAG proposes the use of silicon-pixel detectors to achieve the \textit{full tagging} of the parent meson and the daughter lepton. Both ideas have merged into the Physics Beyond Colliders (PBC) Short-Baseline Neutrino (SBN) beamline study, supported through the PBC initiative at CERN. If deployed at CERN, the SBN beamline would need to be compatible with the operation of the current injector complex including the new SHiP experiment, in particular with respect to the number of protons required. The beamline's intensity requirement must therefore be kept at a minimum. With that in mind, a full optimization of the beamline was conducted to maximize the production of hadrons while fulfilling pile-up and background constraints. This contribution presents the optimized beamline design, elaborating on the techniques used and challenges faced during the design process.
Paper: TUPB009
DOI: reference for this paper: 10.18429/JACoW-IPAC25-TUPB009
About: Received: 23 May 2025 — Revised: 02 Jun 2025 — Accepted: 02 Jun 2025 — Issue date: 10 Jul 2025
TUPB014
The Experimental Storage Ring (ESR) - recent developments
976
The Experimental Storage Ring (ESR) at GSI Darmstadt, Germany is the core instrument for unique physics experiments. It is operated for accumulation, storage, cooling and deceleration of a wide range of heavy ion beams in the energy range from 4-400 MeV/u coming from the synchrotron SIS18 via the FRagment Separator (FRS) or a direct transport line. Low energy decelerated beams can also be fast extracted to the storage ring CRYRING or to the HITRAP facility. The overview of the ESR performance, will be presented here. The features and challenges of the operation with the new control system LSA (LHC Software Architecture) will be outlined as well.
Paper: TUPB014
DOI: reference for this paper: 10.18429/JACoW-IPAC25-TUPB014
About: Received: 28 May 2025 — Revised: 04 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 10 Jul 2025
TUPB017
First results of the new eddy current septum for the CERN PS fast extraction
983
CERN has developed a new fast pulsed septum magnet to replace the aging PS proton extraction septum. The aim is to increase the refurbishment intervals of the magnet and to phase out the old power converter, while allowing energy savings during operation. The new system includes a novel under vacuum eddy current septum magnet, a new third-harmonic fast pulse generator and dedicated control system with post pulse fault analysis for achieving the required flat top precision. This paper will briefly describe the system development and focus on the lessons learned from its construction and report the results of the testing phase.
Paper: TUPB017
DOI: reference for this paper: 10.18429/JACoW-IPAC25-TUPB017
About: Received: 27 May 2025 — Revised: 31 May 2025 — Accepted: 31 May 2025 — Issue date: 10 Jul 2025
TUPB019
Investigation and mitigation of magnetic field emissions in the SMH16 septum system's high-current cable connections
991
The SMH16 system at CERN is a pulsed septum magnet driven by a single period of a flattened sine wave current with a fundamental frequency of approximately 2.5 kHz and a peak current of 28 kA. The magnet connects to its pulse generator via ten high-voltage, high-power cables, each containing go, return, and ground conductors and coarse shielding. Due to the high currents, magnetic field emissions could interfere with nearby equipment and affect electromagnetic compatibility. This work investigates these magnetic field emissions and evaluates potential shielding measures. 2D field simulations of the cable connections to model the emissions and assess the effectiveness of additional shielding configurations have been conducted. To validate the simulations, time-dependent magnetic field measurements using a magnetic near-field probe, and a custom Hall probe were performed on a section of the cable connection in a full-scale test setup of the SMH16 system, both with and without extra shielding around the cable bundle. The results showed good agreement between simulations and measurements. Additional shielding can significantly reduce magnetic field emissions.
Paper: TUPB019
DOI: reference for this paper: 10.18429/JACoW-IPAC25-TUPB019
About: Received: 28 May 2025 — Revised: 30 May 2025 — Accepted: 01 Jun 2025 — Issue date: 10 Jul 2025
TUPB022
Reduction of beam loss at the fast extraction section in J-PARC MR
1002
At J-PARC MR, proton beams are supplied to the neutrino facility via fast extraction (FX). The beam power, which was 500 kW in 2021, reached 800 kW by June 2024, with further upgrades planned. This increase in power has led to a rise in beam loss in the FX section, necessitating countermeasures. Residual doses are high at positions where the FX beam orbit closely approaches the aperture, and the effectiveness of beam loss countermeasures is evaluated by changes in residual dose. By June 2024, residual doses were successfully reduced through adjustments to the beam optics. For further reduction of beam loss, in July 2024, the aperture was expanded at the most upstream position where the beam orbit is in close proximity to the aperture. This report discusses the achievements during subsequent FX operations and outlines plans for further improvements.
Paper: TUPB022
DOI: reference for this paper: 10.18429/JACoW-IPAC25-TUPB022
About: Received: 28 May 2025 — Revised: 03 Jun 2025 — Accepted: 04 Jun 2025 — Issue date: 10 Jul 2025
TUPB023
Simulation studies on bent silicon crystals for loss reduction in slow extraction operation at J-PARC Main Ring
1006
Reducing beam loss during slow extraction remains a critical challenge for the J-PARC Main Ring, which aims to enhance beam power for its 30 GeV proton beam. Since beam loss during slow extraction mainly occurs at the electrostatic septum, it is important to reduce beam loss at this location. Researchers at CERN SPS have recently reported that beam loss can be reduced by installing bent silicon crystals in the accelerator ring and utilizing their charged particle deflection effect. In this paper, we report the results of a simulation study on the expected beam loss reduction effect when the bent silicon crystal is installed upstream of the electrostatic septum of the J-PARC Main Ring and the beam deflection effects of the bent silicon crystal, called channeling or volume reflection, are utilized. The required size and installation position of the silicon crystal, and the required accuracy for adjusting the position and angle will also be reported.
Paper: TUPB023
DOI: reference for this paper: 10.18429/JACoW-IPAC25-TUPB023
About: Received: 28 May 2025 — Revised: 03 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 10 Jul 2025
TUPB026
Research and development study on nanobeam formation using laser-cooled ions for high-precision single-ion irradiation
1017
To realize high-precision single-ion irradiation or implantation, we have proposed a nanobeam formation scheme where single cold ions selectively separated from a two-component Coulomb crystal in a linear Paul trap (LPT) are accelerated to 100 keV and focused on the nanometer scale using electrostatic bipotential lenses. The entire process of laser cooling of trapped ions in the LPT, ion-selective ejection from the LPT, acceleration, and focusing in the lens system is investigated by detailed multiparticle tracking simulations to show the feasibility of ultralow-emittance nanobeam formation and ion focusing properties. According to the simulation results, the fabrication and commissioning of such a single-ion irradiation system are ongoing at Takasaki Institute for Advanced Quantum Science, National Institutes for Quantum Science and Technology toward the application of research and development of quantum materials and devices. We will discuss the simulation results on the behavior of cold ions in the irradiation system and report the latest status of the system development including preliminary experimental results.
Paper: TUPB026
DOI: reference for this paper: 10.18429/JACoW-IPAC25-TUPB026
About: Received: 26 May 2025 — Revised: 31 May 2025 — Accepted: 03 Jun 2025 — Issue date: 10 Jul 2025
TUPB027
Improving the SPS beam extraction efficiency by implementation of a crystal septum
1021
The third-integer resonant extraction of the proton beam from the Super Proton Synchrotron (SPS) at CERN is a technique used for slow extraction of the circulating beam, providing a constant spill of protons to the North Area experiments. Currently, this method employs an electrostatic septum (ZS) to separate the extracted particles from the proton beam circulating in the ring. However, a fraction of the protons is lost on the mechanical parts of the ZS causing its activation, thus, limiting the efficiency of the process. In this work, the first considerations for solving this problem are presented with the implementation of a non-resonant slow extraction scheme that enables the extraction of the particles without the use of the ZS. The extraction efficiency and beam quality are benchmarked using the Xsuite particle tracking framework for a new configuration, which is compared with the present setup.
Paper: TUPB027
DOI: reference for this paper: 10.18429/JACoW-IPAC25-TUPB027
About: Received: 27 May 2025 — Revised: 02 Jun 2025 — Accepted: 02 Jun 2025 — Issue date: 10 Jul 2025
TUPB049
Development and Future Applications of the NARI 70 MeV Cyclotron
1079
The National Atomic Research Institute (NARI) is developing a 70 MeV proton cyclotron, with construction set from 2023 to 2027. The cyclotron is designed to operate at proton energies from 28 to 70 MeV and a maximum current of 1000 micro-amperes. It will serve three main purposes: (1) medical isotope production, (2) proton irradiation testing, and (3) cyclotron-based neutron source development. NARI aims to ensure a stable supply of radioisotopes for nuclear medicine, such as Tl-201, I-123, and Ga-67, while advancing the development of isotopes like Cu-67 and Mo-99. In addition to medical uses, the cyclotron will simulate space radiation environments for aerospace materials testing and radiation measurement standards. The cyclotron will also support neutron-based technologies, benefiting nuclear physics, new materials, and industrial applications. Neutron research will occur in two phases: Phase I (2023–2026) will establish a thermal neutron target station for neutron diffraction studies, and Phase II (2027–2030) will develop a quasi-monoenergetic neutron (QMN) source for soft error rate testing in electronics and a high-resolution neutron imaging station. Expected to be fully operational by 2028, the facility will include seven beamlines, two solid target stations, one gas target station, and specialized laboratories for proton, fast neutron, and thermal neutron research. The NARI 70 MeV cyclotron will support both routine isotope production and advanced scientific research.
Paper: TUPB049
DOI: reference for this paper: 10.18429/JACoW-IPAC25-TUPB049
About: Received: 29 May 2025 — Revised: 05 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 10 Jul 2025
TUPB067
Development of a new cyclotron concept for medical application
1116
Further development of a cyclotron design concept with advantages, such as energy efficiency and cost-effectiveness, is presented. The concept is optimized for non-superconducting cyclotrons. The main feature of the concept is the operation at high frequency (145 MHz) of the accelerating system.
Paper: TUPB067
DOI: reference for this paper: 10.18429/JACoW-IPAC25-TUPB067
About: Received: 28 May 2025 — Revised: 01 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 10 Jul 2025
TUPB072
Progress of beam power upgrade in J-PARC main ring
1124
In the J-PARC main ring (MR), a project to increase the beam power with higher repetition rates and higher beam intensities is now in progress, aiming to achieve 1.3 MW in the fast extraction (FX) mode and >100 kW in the slow extraction (SX) mode. Beam power has generally been increasing as planned with progress of hardware upgrades and beam dynamics tuning; beam powers of 800 kW (FX) and 80 kW (SX) have been achieved as of December 2024. This paper reports on the recent progress of the beam power upgrade in MR.
Paper: TUPB072
DOI: reference for this paper: 10.18429/JACoW-IPAC25-TUPB072
About: Received: 31 May 2025 — Revised: 02 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 10 Jul 2025
TUPB075
Bunch lengthening of the extraction beam using second harmonic in J-PARC RCS
1132
The 3GeV Rapid-Cycling Synchrotron (RCS) at J-PARC supplies the beam to the Main Ring (MR). Under the current operating conditions, there is the longitudinal beam mismatch between RCS and MR. To improve the RCS-MR longitudinal matching, a method for the bunch lengthening of RCS at the extraction is proposed. The method is based on introducing a second harmonic RF voltage at beam extraction and placing the beam at the unstable fixed point. The considerations of the bunch lengthening in the RCS are described in this presentation. The focus is on optimizing the second harmonic RF voltage pattern. Demonstrations of introducing a second harmonic RF voltage are also discussed.
Paper: TUPB075
DOI: reference for this paper: 10.18429/JACoW-IPAC25-TUPB075
About: Received: 07 Apr 2025 — Revised: 05 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 10 Jul 2025
TUPB099
Recent developments in delivering mixed helium and carbon ion beams at MedAustron
1147
Simultaneous irradiation with mixed helium and carbon ions is being proposed for online range verification in carbon radiotherapy. In 2024, a mixed $^4$He$^{2+}$ and $^{12}$C$^{6+}$ beam, generated by sequential injection of helium and carbon ions into the synchrotron, was extracted successfully for the first time at the MedAustron ion beam therapy and research center. This double injection scheme comes with challenges concerning the capture, acceleration, and slow extraction, as injection energy offsets and differences in horizontal phase distributions have to be considered in addition to the small offset in charge-to-mass ratio between $^4$He$^{2+}$ and $^{12}$C$^{6+}$. This proceeding reports on recent developments in the delivery of this mixed ion beam at MedAustron using a double injection scheme, which includes an additional deceleration ramp for helium ions between the injections of helium and carbon, as well as progress towards a measurement setup for the time-resolved quantification of the ion mixing ratio at delivery.
Paper: TUPB099
DOI: reference for this paper: 10.18429/JACoW-IPAC25-TUPB099
About: Received: 27 May 2025 — Revised: 31 May 2025 — Accepted: 04 Jun 2025 — Issue date: 10 Jul 2025
TUPB100
Towards the detection of mixed helium and carbon ion beams using a gas-filled charge exchange cell
1151
Irradiation with mixed helium and carbon ion beams is emerging as a promising approach to treatment monitoring in ion radiotherapy. In contrast to mono-isotopic beams, the full characterization of the mixed beam requires distinguishing ion species of almost identical charge-to-mass ratio, which is not feasible with most conventional beam diagnostic devices. This proceeding proposes a measurement concept that could allow for determining the ion mixing ratio after extraction from the ion source at energies around 10 keV/u. The concept relies on a gas-filled charge exchange cell, where the traversing ions experience electron capture events, followed by an electrostatic or magnetic analyzer and beam intensity measurement. The proposal is accompanied by proof-of-concept measurements performed at the *Helmholtz Zentrum Dresden-Rossendorf (HZDR)*, which showcase the potential but also several challenges associated with the measurement concept.
Paper: TUPB100
DOI: reference for this paper: 10.18429/JACoW-IPAC25-TUPB100
About: Received: 27 May 2025 — Revised: 01 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 10 Jul 2025
TUPB105
A compact synchrotron for cancer therapy with helium ions
1159
In the frame of the Next Ion Medical Machine Study (NIMMS) collaboration based at CERN, a compact synchrotron for radiotherapy with high-intensity helium beams is designed. Interest in helium ions is growing in the major treatment centers, since they provide superior accuracy compared to protons, thanks to their sharper lateral penumbra, and higher linear energy transfer. Their properties lie in-between protons and carbon ions, without the fragmentation problems of the latter. Moreover, their lower magnetic rigidity allows helium-ion accelerators to be more compact than the large carbon-ion machines. The synchrotron design presented in this paper is based on normal-conducting dipole magnets at 1.65 Tesla and has a circumference of 35 meters. Optimized for helium ions, it can also accelerate protons, for treatment and particle radiography, and other species to smaller penetration depths. The design choices for the different systems are described taking into consideration the mechanical integration in a compact layout and operational flexibility. The technology readiness level is evaluated and R&D options to achieve higher performances and reduce energy consumption are identified.
Paper: TUPB105
DOI: reference for this paper: 10.18429/JACoW-IPAC25-TUPB105
About: Received: 28 May 2025 — Revised: 02 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 10 Jul 2025
TUPM025
Conceptual design of a compact synchrotron for proton-and-helium therapy facility
1212
In recent years, proton and heavy-ion therapy has become increasingly widespread in clinical applications, and has emerged as one of the important means for cancer treatment. The commonly used particle types for this therapy are protons and carbon ions. However, further research into the biological effect has found that helium ions have both high biological effectiveness and small penumbra characteristics, which enable more precise locate of the tumor while also effectively killing tumor cells. And the highest energy of the helium ions used in therapy is 235MeV/u. Therefore, the equipment size and cost required for helium ions therapy will be significantly less than that for carbon ions therapy. To this end, this paper proposes a design for a helium-ion therapy synchrotron that also possesses the capability for proton therapy. The design employs eight ultra-high field dipole magnets to achieve a compact envelope function. Additionally, the design incorporates both multi-turn painting injection and mismatched injection methods in two directions, significantly minimizing the use of bump magnets. This results in a highly compact accelerator structure.
Paper: TUPM025
DOI: reference for this paper: 10.18429/JACoW-IPAC25-TUPM025
About: Received: 03 Apr 2025 — Revised: 30 May 2025 — Accepted: 03 Jun 2025 — Issue date: 10 Jul 2025
TUPM053
Design of a resonant slow extraction from the planned DESY IV booster synchrotron
1266
The planned upgrade of the synchrotron light source at DESY, Hamburg will include an upgrade of the booster synchrotron. We discuss the considerations for the design of a slow resonant extraction from this future machine. The implementation of a bent crystal as a potential septum shadower and/or as a septumless option is considered.
Paper: TUPM053
DOI: reference for this paper: 10.18429/JACoW-IPAC25-TUPM053
About: Received: 26 May 2025 — Revised: 01 Jun 2025 — Accepted: 03 Jun 2025 — Issue date: 10 Jul 2025
TUPM114
An extraction scheme for future CEBAF FFA based energy upgrade
1407
Jefferson lab is considering an energy increase from current 12 GeV to 22 GeV for its CEBAF accelerator. This will be accomplished by recirculating 5-6 additional turns through two parallel CEBAF LINACs using an FFA arc at each end of the racetrack. The total recirculation turns would be 10 times, the first four turns use present conventional arcs to make the 180-degree bends from one LINAC to the other. However, the last 5-6 turns will all share a single beam line inside two FFA arcs. This reduces the footprint and the cost of the project significantly. On the other hand, having the trajectories of last 5-6 recirculating beams close to each other makes it challenging to extract beams from different passes with different energies. In this paper we will explain our present extraction system for 12 GeV, our challenges and limitations, and a possible extraction solution for the 22 GeV upgrade with the goal of extracting beam at different turns/energies to different experimental halls.
Paper: TUPM114
DOI: reference for this paper: 10.18429/JACoW-IPAC25-TUPM114
About: Received: 28 May 2025 — Revised: 31 May 2025 — Accepted: 31 May 2025 — Issue date: 10 Jul 2025
TUPS030
Update of the tune ripple canceller system for slow extraction operation in the J-PARC MR
1483
In the slow extraction operation of the J-PARC Main Ring (MR), ensuring the uniformity of the extracted beam's time structure (“spill structure”) is crucial. One primary factor distorting the spill structure is the random fluctuation of the horizontal tune caused by current ripples in the main magnet power supplies. To address this issue, a system called the "tune ripple canceller" has been developed. This system calculates correction values for the horizontal betatron tune based on current ripples and controls the spill structure using fast-responding quadrupole magnets. In 2021, proof-of-principle beam experiments demonstrated its effectiveness in improving the spill structure. Subsequently, as part of the MR's power upgrade plan, the main magnet power supply system was upgraded by 2022. During this upgrade, the current measurement system was reconfigured, and the power spectrum of the current ripples was altered. As a result, it is now urgent to update the hardware and software of the tune ripple canceller system to align with these changes. This paper highlights updates, addresses challenges, and explores strategies to further enhance spill structure control in the MR.
Paper: TUPS030
DOI: reference for this paper: 10.18429/JACoW-IPAC25-TUPS030
About: Received: 28 May 2025 — Revised: 03 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 10 Jul 2025
TUPS038
Low energy beam transport line design for the Sarajevo ion accelerator
1510
The University of Sarajevo Physics Department, in collaboration with CERN’s Accelerator Beam Physics group, proposes a compact linear accelerator design for applied physics research spanning from beam dynamics studies to material surface analysis. The Sarajevo Ion Accelerator (SARAI) consists of an electron cyclotron resonance ion source, a low energy beam transport line (LEBT) and a radiofrequency quadrupole (RFQ). The ion source can produce an array of ions extracted with 30 kV. This study presents an iterative parameter optimization method that suggests two LEBT optics: one for beam diagnostics and another for compact beam matching to the RFQ acceptance. The RFQ discussed here is a 750 MHz, 2.5 MeV/u RFQ, used for medical applications. SARAI RFQ aims at 0.5 - 2 MeV/u. A novel RFQ technology allows a significant reduction in footprint. This paper further discusses plans for source commissioning and potential research applications.
Paper: TUPS038
DOI: reference for this paper: 10.18429/JACoW-IPAC25-TUPS038
About: Received: 27 May 2025 — Revised: 02 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 10 Jul 2025
TUPS052
Development of FFA at Center for Accelerator and Beam Applied Science of Kyushu University
1549
Center for Accelerator and Beam Applied Science of Kyushu University has been established to promote activities in various fields such as, medical, educational and engineering fields at Kyushu University. An accelerator facility, consist of a 10 MeV proton cyclotron, 8 MeV tandem accelerator and of 150 MeV FFA, has been constructed in the center. In this paper, status of the hardware developments and results of the beam commissioning of the FFA in Kyushu University is described.
Paper: TUPS052
DOI: reference for this paper: 10.18429/JACoW-IPAC25-TUPS052
About: Received: 28 May 2025 — Revised: 02 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 10 Jul 2025
WEAN2
Data-driven hysteresis compensation in the CERN SPS main magnets
1674
Magnetic hysteresis and eddy current decay continue to challenge beam quality and operational consistency in multi-cycling machines like the Super Proton Synchrotron (SPS) at CERN. Building on our previous work, this paper presents improvements in the data-driven approach for magnetic field modelling to enhance the reproducibility of SPS dipole and quadrupole fields and thus maintain stable beam parameters across all operational cycles. The method is based on feed-forward correction using magnetic field forecasting with machine learning. It now includes additional operational experience and demonstrates that the field error compensation can reliably be used in operation. This contribution proves that hysteresis compensation can be achieved without a feedback system based on expensive installations with online field measurements in reference magnets. The performance improvements achieved by eliminating the need for manual adjustments and reducing time- and energy-consuming accelerator pre-cycles are presented. The paper also sets the stage for future application in higher-order magnets, like sextupoles and octupoles, as well as on other CERN synchrotrons.
Paper: WEAN2
DOI: reference for this paper: 10.18429/JACoW-IPAC25-WEAN2
About: Received: 27 May 2025 — Revised: 04 Jun 2025 — Accepted: 04 Jun 2025 — Issue date: 10 Jul 2025
WEPB025
The study of the eddy current-type septum magnet for fast extraction in J-PARC MR
1784
The eddy current type septum magnets (Eddy-septa) are used for fast extraction in J-PARC MR from 2022. Currently, the operation of the Eddy-septa is very stable. However, we have some still technical issue. One is an output pulsed current measurement by current transfers. The peak value of the output pulsed current is measured pulse by pulse and the measured value is used for a feedback system using by PXI system for long-term stability. The output current is also measured with different current transfer in same time for double checking. However, we don't have good reproducibility with the measurement result by the PXI feedback system yet. We have found the noise which are generated by the kicker magnets and extraction beam in 2023, thus, we started to investigate the detail of the process of generation and method of removal. Second is residual field along the circulating beam line in Eddy-septa. We had reported the leakage field by exciting current on the circulating beam line and the strength was very small. In summer of 2023, we found large residual field on the same line. In this presentation, we report the status of measurement of output current, and residual field.
Paper: WEPB025
DOI: reference for this paper: 10.18429/JACoW-IPAC25-WEPB025
About: Received: 27 May 2025 — Revised: 03 Jun 2025 — Accepted: 04 Jun 2025 — Issue date: 10 Jul 2025
WEPB042
Third order resonance correction using new Trim-S system in J-PARC MR
1826
In the Japan Proton Accelerator Research Complex (J-PARC) Main Ring (MR), to address the issue of resonance correction for third-order resonances in both on- and off-momentum particles, an upgrade project utilizing 24 Trim-S units has been proposed based on numerical simulations. As a first step in verifying its effectiveness, four additional Trim-S (new Trim-S) power supplies, configured with a System-on-Chip (SoC) Field Programmable Gate Array (FPGA) controller, have been installed. The performance of the new system was experimentally verified by correcting the resonance using these 4 new Trim-S units. Beam loss was successfully reduced compared to that with the original Trim-S system, demonstrating the effectiveness of the new system.
Paper: WEPB042
DOI: reference for this paper: 10.18429/JACoW-IPAC25-WEPB042
About: Received: 14 Apr 2025 — Revised: 31 May 2025 — Accepted: 02 Jun 2025 — Issue date: 10 Jul 2025
WEPB085
Design and development of an extraction septum for the MYRRHA 100 MeV proton target facility
1918
SCK CEN is developing MYRRHA, a large-scale Accelerator Driven System. MYRRHA shall be a subcritical nuclear reactor driven by a high-power linear proton accelerator, which sustains the nuclear reaction. In the initial phase, known as the MINERVA project, the goal is to demonstrate the high reliability requirements on the accelerator. The two primary end users of the MINERVA project are the Full Power Facility and the Proton Target Facility. In collaboration with SCK CEN, CERN studied and designed an extraction septum for the 100 MeV Proton Target Facility. Two distinct topologies have been evaluated magnetically and tracked particle simulations have been executed to validate the designs. A preferred low-power solution has been retained for a subsequent detailed design. A final magnetic verification to confirm the mechanical design requirements has been carried out. This has allowed to develop a detailed 3D mechanical design including all manufacturing tolerances required for subcontracting the magnet fabrication to the industry. This article covers the 2- and 3-dimensional magnetic modelling, the tracked particle simulations and the mechanical design of the septum magnet.
Paper: WEPB085
DOI: reference for this paper: 10.18429/JACoW-IPAC25-WEPB085
About: Received: 28 May 2025 — Revised: 04 Jun 2025 — Accepted: 04 Jun 2025 — Issue date: 10 Jul 2025
WEPB087
Design of FFA magnet for the laser-hybrid accelerator for radiobiological applications (LhARA)
1925
LhARA, which stands for “Laser-hybrid Accelerator for Radiobiological Applications”, is a novel and flexible facil- ity dedicated to research in radiobiology. A proton beam of energy up to 15 MeV can be produced by a laser driven source, the beam then enters a Fixed Field Alternating (FFA) gradient accelerator for acceleration to produce a variable ex- traction energy between 15-127 MeV. To avoid uncontrolled beam loss, the operational tune was picked carefully to avoid resonances. The magnetic field must be adjusted to ensure that the tune stays at the same working point for different energy ranges. The FFA ring uses combined-function spiral magnets, which create a radial magnetic gradient through distributed conductors wrapped around the pole, each car- rying a different current. A three-dimensional study was carried out in OPERA 3D and the parameters of the magnet were optimized. The results showed that resonances up to fourth order were avoided for the entire range of acceleration for different operational energies entire range of acceleration and different operational energies.
Paper: WEPB087
DOI: reference for this paper: 10.18429/JACoW-IPAC25-WEPB087
About: Received: 28 May 2025 — Revised: 02 Jun 2025 — Accepted: 03 Jun 2025 — Issue date: 10 Jul 2025
WEPM012
Status of the CERN optics measurement and correction analysis tools
1972
With a change in the LHC machine optics foreseen for 2025 and the possible reduction of beta-star, optics commissioning will become even more of a challenge for the CERN Optics Measurement and Correction (OMC) team. In particular, the increased sensitivity of the optics to non-linear imperfections, requiring a plethora of accurate measurements, is expected to be a time consuming task. In preparation, continuous effort has been undertaken to develop new correction strategies and convert them into ready-to-use algorithms, allowing the automation of repetitive tasks while keeping the python-base software tools up-to-date. In this paper the status of these tools is summarized with highlights and improvements underlined. These tools are now widely used beyond the LHC in the entire CERN accelerator complex, as well as in Super-KEKB and for Future Circular Collider studies, and could be of great interest to correct and improve the optics in other machines.
Paper: WEPM012
DOI: reference for this paper: 10.18429/JACoW-IPAC25-WEPM012
About: Received: 26 May 2025 — Revised: 03 Jun 2025 — Accepted: 04 Jun 2025 — Issue date: 10 Jul 2025
WEPM016
Benchmarking of LHC beam intensity dependent transverse tune corrections at injection energy
1988
Observations of betatron tune evolution during LHC beam injection have revealed a significant tune error, strongly correlated with beam intensity. This finding highlights limitations in the existing feedforward corrections based on Laslett coefficients. A dedicated machine development study was conducted to refine intensity-dependent tune corrections. Utilizing high-precision, per-bunch tune measurements facilitated by the LHC transverse feedback system, the study characterized tune shifts under varying intensities and beam conditions. The results uncovered pronounced discrepancies between horizontal and vertical planes, which deviate from predictions made by the current correction model. These insights provide a critical foundation for improving the accuracy of intensity-dependent tune adjustments, impacting operational stability and efficiency, in particular when considering future operation of the high-luminosity LHC.
Paper: WEPM016
DOI: reference for this paper: 10.18429/JACoW-IPAC25-WEPM016
About: Received: 23 May 2025 — Revised: 05 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 10 Jul 2025
WEPM028
Beam instability suppression during debunching process through slippage factor tuning in the J-PARC Main Ring
2016
The J-PARC Main Ring achieves a high extraction efficiency of 99.5% during 30 GeV slow extraction at the current beam power of 80 kW. However, at beam powers above 30 kW, we observed ring-wide beam losses due to transverse beam instability associated with vacuum pressure rises and electron cloud effects, which are believed to be triggered by longitudinal microwave structures. To achieve stable operation at 80 kW, we implemented phase offset injection into RF buckets and two-step RF voltage reduction during debunching. For planned higher-power operations, we propose tuning the slippage factor to suppress the microwave structures during debunching. The Main Ring features a unique imaginary transition gamma lattice, and we discovered that the slippage factor can be adjusted using appropriate combinations of four quadrupole families in the arc sections while maintaining the operating tune and achromatic conditions in the long straight sections. Such slippage manipulation would be impossible in a ring with a conventional FODO lattice. The slippage factor can be ramped from its nominal value to a suppressing value during acceleration.
Paper: WEPM028
DOI: reference for this paper: 10.18429/JACoW-IPAC25-WEPM028
About: Received: 28 May 2025 — Revised: 01 Jun 2025 — Accepted: 01 Jun 2025 — Issue date: 10 Jul 2025
WEPM040
Improving the beam extraction efficiency from SPS to the North Area at CERN using octupole phase space folding technique
2058
The High Intensity ECN3 (HI-ECN3) project aims to increase the number of protons per pulse delivered to a new experimental facility in CERN’s North Area up to $\sim 4 \cdot 10^{19}$ per year. Such an upgrade requires the reduction of the beam loss at SPS electrostatic septum (ZS) by at least a factor of four, since the activation of this device is the main factor constraining transition to the higher beam intensity. In this work we demonstrate one of the possible solutions to this problem that relies on octupole assisted folding of the beam in phase space. Implementation of this technique allowed to significantly reduce the losses at the ZS whilst transferring the beam through the LSS2 line, which connects the SPS and the transfer lines in the North Area, without deteriorating the transmission.
Paper: WEPM040
DOI: reference for this paper: 10.18429/JACoW-IPAC25-WEPM040
About: Received: 28 May 2025 — Revised: 04 Jun 2025 — Accepted: 04 Jun 2025 — Issue date: 10 Jul 2025
WEPM046
Optimising multi-turn extraction at CERN using transverse feedback
2077
Initial experimental investigations of transverse beam splitting, carried out at the CERN Proton Synchrotron, have demonstrated that transverse feedback is highly effective in controlling the characteristics of the transversally split beam. The feedback notably improves the intensity distribution among the beamlets and the emittance of the core, which is the portion of the beam remaining near its centre after the resonance-crossing process. The transverse feedback is set in resonance with the horizontal betatron tune while the tune crosses the fourth-order resonance, creating a double-resonance condition. A simple Hamiltonian model has been employed to explore the underlying double-resonance mechanism. This paper thoroughly examines detailed numerical simulations based on a realistic lattice model alongside beam measurements, to identify optimisation strategies for the use of transverse feedback in controlling the properties of split beams.
Paper: WEPM046
DOI: reference for this paper: 10.18429/JACoW-IPAC25-WEPM046
About: Received: 02 Jun 2025 — Revised: 02 Jun 2025 — Accepted: 02 Jun 2025 — Issue date: 10 Jul 2025
WEPM048
Demonstrating beam splitting through stable islands formed by the third-order resonance at the CERN Super Proton Synchrotron
2085
In recent years, several new beam manipulation techniques have been proposed that exploit the crossing of nonlinear resonances and the use of stable islands of the transverse phase space. One such manipulation is a novel approach to slow extraction, which combines particle trapping in stable islands with the use of bent crystals to reduce losses on the extraction septum. As a first step towards testing this approach, measurements were performed at the CERN Super Proton Synchrotron (SPS) to demonstrate beam splitting using stable islands of the third-order resonance generated and controlled by sextupole and octupole magnets. The phase-space topology was reconstructed by displacing the beam and observing the turn-by-turn evolution of the signal of the beam position monitors. The beam splitting was achieved by varying both the machine tune and the radial steering of the beam. The measurement results were found to be in excellent agreement with the tracking simulations.
Paper: WEPM048
DOI: reference for this paper: 10.18429/JACoW-IPAC25-WEPM048
About: Received: 19 May 2025 — Revised: 31 May 2025 — Accepted: 01 Jun 2025 — Issue date: 10 Jul 2025
WEPS002
Performance of the diode stack with resistors to suppress beam instability at the J-PARC RCS
2240
The main source of beam instability in the J-PARC 3-GeV RCS is the impedance of the eight installed kickers. This arises because one end of each kicker magnet is shorted while the other end is left open during beam acceleration. The shorted-end configuration provides the benefit of power savings during beam extraction from the RCS. However, it also excites beam instability. To retain the energy-saving benefit while suppressing beam instability, we developed a diode stack with resistors and inserted it at the open ends of four kickers. This configuration effectively suppresses beam instability for smaller-emittance beams, which are delivered to the MR at J-PARC.
Paper: WEPS002
DOI: reference for this paper: 10.18429/JACoW-IPAC25-WEPS002
About: Received: 26 May 2025 — Revised: 31 May 2025 — Accepted: 31 May 2025 — Issue date: 10 Jul 2025
WEPS028
Quadrupole pumping for bunch shortening in the Proton Synchrotron and Super Proton Synchrotron at CERN
2302
Quadrupole pumping is a longitudinal manipulation technique for bunch shortening, which works by modulating the RF voltage at twice the synchrotron frequency to excite bunch length oscillations. These controlled oscillations rotate the bunch in longitudinal phase space, with extraction set for when the bunch is shortest. Higher RF harmonics can also be used to linearise the synchrotron frequency distribution, reducing the formation of tails. Recently, quadrupole pumping has been proposed as a method for achieving ultra short bunches for proton-driven plasma wakefield accelerators such as the AWAKE experiment. In this contribution, we assess the performance of quadrupole pumping for the first time in the Proton Synchrotron (PS) and Super Proton Synchrotron (SPS) at CERN. Using simulations and beam measurements, we compare the effectiveness of this technique (without linearisation) against other bunch-shortening methods, including the unstable phase jump and the non-adiabatic voltage jump.
Paper: WEPS028
DOI: reference for this paper: 10.18429/JACoW-IPAC25-WEPS028
About: Received: 27 May 2025 — Revised: 03 Jun 2025 — Accepted: 03 Jun 2025 — Issue date: 10 Jul 2025
WEPS029
Predicting losses in the SPS using longitudinal tomography during bunch shortening in the PS
2306
The efficient transfer of protons from the Proton Synchrotron (PS) to the Super Proton Synchrotron (SPS) is crucial for beams in the Large Hadron Collider (LHC). A particular challenge at the intensities required for the High-Luminosity LHC is the handover from a 40 MHz to a 200 MHz RF system. This requires a non-adiabatic bunch shortening in the PS triggered by a fast RF voltage jump. However, nonlinearity of the synchrotron frequency distribution causes tails to emerge during rotation, resulting in uncaptured beam in the SPS. The uncaptured particles lost at the start of acceleration in the SPS, and the additional flat bottom losses, can currently only be evaluated with the beam intensity and loss monitors. In this work, detailed studies of the bunch rotation in the PS were carried out both in simulations and in measurements. A tomography-based tool was developed to predict uncaptured losses in the SPS from bunch profile measurements in the PS during bunch shortening. This tool enables detailed monitoring of the PS-to-SPS transfer of LHC-type beams by identifying potential losses due to uncaptured beam, before injection into the SPS.
Paper: WEPS029
DOI: reference for this paper: 10.18429/JACoW-IPAC25-WEPS029
About: Received: 27 May 2025 — Revised: 01 Jun 2025 — Accepted: 02 Jun 2025 — Issue date: 10 Jul 2025
THPB053
Compiling a life cycle inventory of a large accelerator facility: The ISIS-II neutron and muon source life cycle assessment
2620
The ISIS-II Neutron and Muon Source, the proposed successor to the ISIS Neutron and Muon Source at the Rutherford Appleton Laboratory, UK, presents a unique opportunity to integrate environmental sustainability practises from its inception. A Life Cycle Assessment (LCA) was performed during the early feasibility and design stage to evaluate the potential environmental impacts across construction, operation, and decommissioning phases, and to identify opportunities for impact reduction. With many accelerator components, elements and systems still in early optioneering stages, numerous assumptions were required to model the facility. This work explores these assumptions and the use of a simplified LCA framework, focusing on bulk material selection, future operational resource management, and strategies for managing non-radioactive and radioactive materials at decommissioning. Updated results of the LCA and identified strategies to minimize and mitigate negative environmental impacts are presented, emphasizing the role of LCAs in embedding sustainability into decision-making for large-scale scientific facilities.
Paper: THPB053
DOI: reference for this paper: 10.18429/JACoW-IPAC25-THPB053
About: Received: 28 May 2025 — Revised: 31 May 2025 — Accepted: 04 Jun 2025 — Issue date: 10 Jul 2025
THPB057
A novel approach to qualify the straightness of electrostatic septa for the SPS slow extraction
2626
The quality of slow extraction from the SPS (Super Proton Synchrotron) to the North Area is critically influenced by the straightness tolerance of the electrostatic septum. Past observations have identified a degradation of the anode body straightness, resulting in an increased beam loss during ex- traction. A new metrology bench including optical sensors has been developed to cope with the tolerance requirements while also allowing process automation. Two distinct mea- surement procedures are currently employed: one for the anode noses and another for the individual wire metrology. A control system was developed to automate the metrology and analysis process, allowing operator and time-independent measurements and increasing process accuracy. The find- ings from these investigations provide accurate information in case corrective machining of the anode body is required. The metrology method and the described nose scan approach will further reduce beam loss during the slow extraction pro- cess.
Paper: THPB057
DOI: reference for this paper: 10.18429/JACoW-IPAC25-THPB057
About: Received: 28 May 2025 — Revised: 05 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 10 Jul 2025
THPB058
Status of the low-Z SPS slow extraction electrostatic septum development
2630
The impact of high-flux protons on beam loss during slow extraction from the SPS to the North Area has been discussed, and improvements have been proposed focusing on reducing activation, lifetime reduction, and anode body distortion. The conducted studies shall demonstrate the feasibility of replacing the stainless-steel tank, flanges, and anode body with low-Z materials. A reduced-length prototype was fabricated to demonstrate mechanical, electrical, and vacuum performance. The paper presents the vacuum vessel development from the reduced-length prototype to the full-length setup, including numerical analysis. Prototype qualification tests, including vacuum performance, leak-tightness, high-voltage feedthrough performance, and deformation during evacuation, will be discussed to confirm that the tank remains within predicted non-linear buckling limits.
Paper: THPB058
DOI: reference for this paper: 10.18429/JACoW-IPAC25-THPB058
About: Received: 28 May 2025 — Revised: 30 May 2025 — Accepted: 31 May 2025 — Issue date: 10 Jul 2025
THPB096
Utilization of renewable energies for sustainable accelerator operation at KIT
2670
The Karlsruhe Institute of Technology operates the accelerator test facility Karlsruhe Research Accelerator, which also provides synchrotron radiation at 2.5 GeV. Roughly one third of the wall-plug power is used for cooling. Optimizing the infrastructure for cooling has a huge impact on the overall sustainability. To reduce the environmental impact a thermal well system was installed. It reduces the base heat load by eliminating one of three 500 kW cooling units. This paper describes the challenges, such as iron-manganese rich groundwater, and their solution for our 1 MW passive cooling system. The average energy consumption of 28 kW for the thermal well infrastructure is compensated by a new 540 kWp solar power plant. This paper elaborates on the commissioning of the wells and shows the first results of this overall sustainable cooling concept.
Paper: THPB096
DOI: reference for this paper: 10.18429/JACoW-IPAC25-THPB096
About: Received: 28 May 2025 — Revised: 01 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 10 Jul 2025
THPM001
Magnetic field control in the MedAustron synchrotron
2687
MedAustron, a synchrotron-based ion therapy centre in Austria, is focused on enhancing cancer treatment performance. A key improvement opportunity lies in the regulation of the main ring bending dipoles, which currently require time-consuming procedures to ensure reproducibility and reliability of the associated magnetic fields (B-Fields). Other therapy centres globally address this through a traditional B-train or similar systems to regulate on the B-Field and mitigate parasitic effects. In contrast to that, we propose a novel approach utilising a single Hall probe measurement inside a reference magnet, fused with a magnet model to provide real-time, high accuracy estimates of the integral B-Field for regulation. This technique, combined with a tailored controller, is evaluated under typical therapy cycling conditions. The system's performance is demonstrated through metrological analysis and beam property comparisons. Most importantly, the results show the possibility of significant improvements in treatment time reduction. Ultimately, the already achievable beam position accuracy, and spill structure in the treatment rooms, enable the start of commissioning in 2025.
Paper: THPM001
DOI: reference for this paper: 10.18429/JACoW-IPAC25-THPM001
About: Received: 28 May 2025 — Revised: 03 Jun 2025 — Accepted: 04 Jun 2025 — Issue date: 10 Jul 2025
THPM009
Model-based optimisation for automated multi-turn extraction tuning at the CERN Proton Synchrotron
2703
Multi-Turn Extraction (MTE) is a resonance-based technique employed in the CERN Proton Synchrotron (PS) to split the beam in horizontal phase space before extraction to the Super Proton Synchrotron (SPS). The splitting efficiency is evaluated based on the uniformity of intensities across the beamlets, requiring fine-tuning of multiple parameters. In this paper, we investigate the influence of key parameters on MTE efficiency to improve the understanding of their impact on the process. Using a Gaussian Process model and various visualization techniques, we assess the sensitivity of the MTE efficiency to horizontal tune, transverse feedback gain, excitation frequency, beam intensity and magnetic hysteresis. Results from experiments and simulations indicate a complex, non-convex relationship between MTE performance and the parameters listed above. Additionally, external factors such as thermal fluctuations may contribute to performance variability. Our findings highlight the need for a model-based controller to counteract parameter drift, thereby ensuring consistent MTE beam quality during operation. We propose a solution supported by experimental results.
Paper: THPM009
DOI: reference for this paper: 10.18429/JACoW-IPAC25-THPM009
About: Received: 26 May 2025 — Revised: 30 May 2025 — Accepted: 01 Jun 2025 — Issue date: 10 Jul 2025
THPM046
Stand-alone operation of the dual-core cryogenic current comparator for FAIR
2785
The Cryogenic Current Comparator (CCC) is a superconducting device for measurement of low intensity beams with magnetic fields in the range of fT. It uses a Superconducting Quantum Interference Device (SQUID) as an ultrasensitive magnetometer and an elaborated superconducting shield for its protection from external magnetic fields. The system is operated in a helium bath cryostat, which has to fulfill many requirements, such as being non-magnetic, pressure/temperature stable (mK), vibration dampening, UHV fit, bakable, compact and accessible for maintenance and repair. First operation of a CCC as beam current monitor was achieved in the 90s at GSI. The idea has been updated for measurement of slow extracted beams and exotic ions at FAIR, and since 2014 there has been steady optimization by an international collaboration of expert institutes. Looking at noise figures and current resolution as well as practical applicability and costs, a Dual-Core CCC (DCCC) has turned out as best candidate for FAIR. In parallel to detector development the cryostat has been investigated and improved. It has recently achieved stand-alone operation, which is a main requirement for FAIR.
Paper: THPM046
DOI: reference for this paper: 10.18429/JACoW-IPAC25-THPM046
About: Received: 27 May 2025 — Revised: 03 Jun 2025 — Accepted: 04 Jun 2025 — Issue date: 10 Jul 2025
THPM059
Development of a DAQ system for a High Resolution cavity BPM for the future linear collider
2807
A cavity beam position monitor (cBPM) developed by CEA Saclay was installed at the end of the Accelerator Test Facility (ATF) linac to evaluate the combined performance of the monitor and its associated signal processing system. The setup incorporates a down-conversion architecture inspired by Royal Holloway, University of London (RHUL), and employs a digital down-conversion (DDC) algorithm to extract beam position. This configuration enables highsensitivity measurements of the transverse beam position. Preliminary results confirm successful signal acquisition and a clear position-dependent response, validating the integrated performance of the cBPM, analogue electronics, and digital processing chain. The results underscore the necessity of reliable local oscillator (LO) phase-locking to ensure precise position determination.
Paper: THPM059
DOI: reference for this paper: 10.18429/JACoW-IPAC25-THPM059
About: Received: 28 May 2025 — Revised: 02 Jun 2025 — Accepted: 03 Jun 2025 — Issue date: 10 Jul 2025
THPM071
Synchronous phase measurement and study at the Taiwan Photon Source
2835
A bunch-by-bunch synchrotron phase detector system has been implemented to investigate the synchronous phase behavior of the storage ring at the Taiwan Photon Source. This detector employs I/Q demodulation to cal-culate the beam phase on a bunch-by-bunch basis. The acquired data is integrated into the accelerator control system, visualized through a graphical user interface, and made available for further analysis. Independent component analysis (ICA) is employed to identify under-lying sources. For a trapezoid-like filling pattern, transi-ent beam loading effects are clearly observed in the flat-top region, whereas significant phase variations occur along the sloped edges of the pattern. During the beam decay period, an in-phase synchrotron phase oscillation at 7 kHz is observed, which originates from the rotation frequency of the radio-frequency transmitter. During injection, three distinct modes are identified through ICA decomposition. Among them, the amplitude of the syn-chronous oscillation mode shows a strong dependence on the injected bucket address.
Paper: THPM071
DOI: reference for this paper: 10.18429/JACoW-IPAC25-THPM071
About: Received: 20 Apr 2025 — Revised: 30 May 2025 — Accepted: 31 May 2025 — Issue date: 10 Jul 2025
THPM113
Trajectory steering for DC beams at the CERN SPS using reinforcement learning based on intensity measurements
2928
The slow extracted beams at the CERN Super Proton Synchrotron (SPS) are transported over several 100 m long transfer lines to three targets in the CERN North Area Experimental Hall. The experiments need intensity fluctuations to be entirely eliminated over the roughly 5 s particle spill, requiring full debunching of the extracted beams. In this environment, secondary emission monitors (SEMs) have to replace the conventional beam position monitoring systems that rely on RF structure, with the intensity difference on split secondary emission foils used to indicate the beam position. Traditional trajectory correction algorithms however fail when the beam ends up on a single foil. This paper summarises successful first tests with reinforcement learning (RL) to learn to correct the trajectory based on foil intensity measurements. The RL agents were trained in simulation and then successfully transferred to the real accelerator environment. Results of the application of the trained RL agents for the alignment of moveable split foils in front of the targets will also be presented.
Paper: THPM113
DOI: reference for this paper: 10.18429/JACoW-IPAC25-THPM113
About: Received: 26 May 2025 — Revised: 02 Jun 2025 — Accepted: 04 Jun 2025 — Issue date: 10 Jul 2025
THPM120
Application of large language models for the extraction of information from particle accelerator technical documentation
2935
The large set of technical documentation of legacy accelerator systems, coupled with the retirement of experienced personnel, underscores the urgent need for efficient methods to preserve and transfer specialized knowledge. This paper explores the application of large language models (LLMs), to automate and enhance the extraction of information from particle accelerator technical documents. By exploiting LLMs, we aim to address the challenges of knowledge retention, enabling the retrieval of domain expertise embedded in legacy documentation. We present initial results of adapting LLMs to this specialized domain. Our evaluation demonstrates the effectiveness of LLMs in extracting, summarizing, and organizing knowledge, significantly reducing the risk of losing valuable insights as personnel retire. Furthermore, we discuss the limitations of current LLMs, such as interpretability and handling of rare domain-specific terms, and propose strategies for improvement. This work highlights the potential of LLMs to play a pivotal role in preserving institutional knowledge and ensuring continuity in highly specialized fields.
Paper: THPM120
DOI: reference for this paper: 10.18429/JACoW-IPAC25-THPM120
About: Received: 21 May 2025 — Revised: 04 Jun 2025 — Accepted: 04 Jun 2025 — Issue date: 10 Jul 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: 10 Jul 2025