MOPS
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Monday Poster Session: MOPS
02 Jun 2025, 16:00 -
18:00
MOPS003
Towards operational reality with laser assisted charge exchange
571
Laser-Assisted Charge Exchange (LACE) is being developed at the Spallation Neutron Source (SNS) as a potential replacement for injection foils, which are not expected to endure in the 10 MW beam power regime. Previous experimental demonstrations have achieved highly efficient charge exchange of H⁻ ions to protons for beam durations of up to microseconds. A refined method, capable of scaling to full millisecond duty cycles, has been experimentally validated and aligns with theoretical models. The current phase of development focuses on optimizing laser and beam parameters for LACE using a newly installed, flexible experimental setup in the High-Energy Beam Transport (HEBT) line at SNS. This setup takes advantage of the upgraded SNS beam energy of 1.3 GeV, offering greater flexibility in selecting laser wavelengths for the experiments. Simultaneously, efforts are underway to design a LACE ring injection system that fits within the spatial constraints of the existing SNS ring injection region. This presentation will provide an update on the progress of these developments.
Paper: MOPS003
DOI: reference for this paper: 10.18429/JACoW-IPAC25-MOPS003
About: Received: 23 May 2025 — Revised: 31 May 2025 — Accepted: 31 May 2025 — Issue date: 06 Jun 2025
MOPS004
Longitudinal hollow electron beam
574
The intra-beam scattering in high charge state intense heavy ion beams is a problem worth considering. With the help of controlling the longitudinal distribution of the ion beam, it may be possible to alleviate the ion beam loss and to improve the ion beam lifetime caused by intra-beam scattering. Unlike the traditional cooling process of direct current electron beams or longitudinal uniform distribution electron beams, a longitudinal hollow electron beam is used to cool heavy ion beams. Ions at the edge of the ion beam will receive stronger cooling, while ions at the center of the ion beam will receive weaker cooling, avoiding overcooling at the center of the ion beam. This paper discusses the generation, measurement, and related issues of longitudinal hollow electron beams. Corresponding solutions and suggestions have been proposed for the problems and challenges that may be encountered in the research. The cooling process of longitudinal hollow electron beams will be simulated and experimentally studied in the further, with the hope of obtaining beneficial effects.
Paper: MOPS004
DOI: reference for this paper: 10.18429/JACoW-IPAC25-MOPS004
About: Received: 09 May 2025 — Revised: 30 May 2025 — Accepted: 02 Jun 2025 — Issue date: 06 Jun 2025
MOPS005
Adiabatic capture in high-intensity, high-power rings
578
Finding the optimal RF voltage ramp to capture coasting beams in high intensity rings has been the subject of ongoing study for many decades. We are motivated to revisit the topic with a view to capturing coasting, stacked beams in a future high intensity, high power FFA. However, the results have general applicability. We compare various voltage laws including linear, bi-linear and iso-adiabatic through simulation and experimentally, making use of the ISIS synchrotron. Making use of longitudinal tomography, we seek to establish the voltage program that minimises the captured beam emittance.
Paper: MOPS005
DOI: reference for this paper: 10.18429/JACoW-IPAC25-MOPS005
About: Received: 28 May 2025 — Revised: 04 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 06 Jun 2025
MOPS006
The Vaccaro stability diagram of scaling FFAs
582
Fixed Field Accelerators (FFAs) are a promising candidate for future high intensity machines such as ISIS-II. It follows that the largely unexplored topic of coherent transverse beam instabilities in these machines is of increasing importance. Transverse instabilities, such as head-tail, can be mitigated in synchrotrons by adjusting the chromaticity appropriately. However, in scaling FFAs, the chromaticity is fixed at zero by design. On the other hand, the relatively strong tune shift with amplitude caused by the nonlinear field of FFA magnets provides a source of Landau damping. Here we evaluate the resulting stability region in the complex tune shift plane comparing an analytical prediction based on the extracted detuning with amplitude with the results from numerical tracking simulations. Hence, the impedance threshold of FFAs can be established.
Paper: MOPS006
DOI: reference for this paper: 10.18429/JACoW-IPAC25-MOPS006
About: Received: 28 May 2025 — Revised: 04 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 06 Jun 2025
MOPS007
Characterisation and mitigation of RF knockout
586
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: 06 Jun 2025
MOPS008
Introduction of key performance indicators for the GSI accelerator facility
590
The GSI Facility consists of several accelerators, offer-ing the distinctive capability to provide different ion beams with varying characteristics to a range of experi-ments simultaneously. In order to facilitate the monitor-ing of machine performance across diverse beam produc-tion chains and experiments, a Key Performance Indica-tor (KPI) metrics has been introduced. The CRYR-ING@ESR team has completed an initial KPI assessment of the ion storage ring and developed procedure to ana-lyse beam diagnostic data offline. Initial analysis has identified lacking information and features in the FAIR Archiving System (FAS) and data structures to support automated tracking of machine performance. This paper will present detailed definitions of KPIs to enable quanti-tative, beam-based accelerator performance measure-ment, an assessment of their implementation and an outline of future developments.
Paper: MOPS008
DOI: reference for this paper: 10.18429/JACoW-IPAC25-MOPS008
About: Received: 27 May 2025 — Revised: 05 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 06 Jun 2025
Study on high current laser ion source with an inner solenoid
Laser ion sources can produce a very high pulsed beam current, but still more than 90% of the beam is lost. In order to further increase the beam current of the laser ion source, this study installed a solenoid in the ion source target chamber and investigated the relationship between the solenoid and the generated beam current.
MOPS011
Improvement on beam-based alignment methods by reliability weighted average technique
593
Accurate determination of magnet centres seen by beams is the key to a successful commissioning of a particle accelerator storage ring. In this paper, several techniques to improve the beam-based alignment for a circular accelerator storage ring are introduced. Firstly, a formula to propagate the uncertainties from linear fitting is given. Secondly, a reliability weighted averaging technique based on uncertainties are applied to mitigate the impact of outliers. Thirdly, studies show that the accuracy and precision of quadrupole centre locations can be refined by using multiple corrector magnets in the process. Finally, to improve the efficiency when using multiple correctors, a monte-carlo technique is utilized. The resulting distributions of all BPM-to-Quad offset residuals derived from simulations are presented.
Paper: MOPS011
DOI: reference for this paper: 10.18429/JACoW-IPAC25-MOPS011
About: Received: 27 May 2025 — Revised: 31 May 2025 — Accepted: 01 Jun 2025 — Issue date: 06 Jun 2025
MOPS014
Development of a 500 MHz high power solid state power amplifier based on GaN transistors
597
The adoption of Solid State Power Amplifier (SSPA) is rapidly increasing in major accelerators worldwide, replacing tube amplifiers such as Klystron and IoT. This study aimed to develop a High-Power RF system for Multipurpose Synchrotron Radiation Accelerators and to design and implement a GaN transistor-based SSPA. Through this research, we verified control performance equivalent to that of a 150 kW SSPA and successfully developed a prototype of a 5 kW RF module. Experimental results confirmed that the GaN transistor-based SSPA provides high efficiency and stable performance in the 500 MHz band, and based on this, we established a performance assurance plan for the 150 kW SSPA. This study demonstrates that GaN devices can effectively replace LDMOS devices with similar performance and competitiveness in the RF applications operating in the 500 MHz frequency range, which has traditionally been dominated by LDMOS. These results have significant implications for enhancing the performance and efficiency of High-Power RF systems and are expected to greatly expand the potential applications of GaN-based SSPA in various scientific and industrial research fields.
Paper: MOPS014
DOI: reference for this paper: 10.18429/JACoW-IPAC25-MOPS014
About: Received: 28 May 2025 — Revised: 03 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 06 Jun 2025
MOPS015
Exploring the null space of the chromaticity response matrix at the Diamond Light Source
601
Many different techniques have been investigated at Diamond for optimising sextupole strengths*. One method not previously studied is to exploit the null space of the chromaticity response matrix. By performing a singular value decomposition (SVD) of the chromaticity response matrix, combinations of sextupole strengths are identified which alter the nonlinear lattice whilst keeping the chromaticity unchanged. Applying these sextupole strength changes opens an avenue to improve the beam lifetime and the injection efficiency at fixed chromaticity, thereby preserving the instability thresholds from collective effects. The results of applying this technique are presented both for beam tracking simulations for the Diamond-II lattice, including machine errors, and for machine-based measurements on the present Diamond synchrotron.
Paper: MOPS015
DOI: reference for this paper: 10.18429/JACoW-IPAC25-MOPS015
About: Received: 28 May 2025 — Revised: 30 May 2025 — Accepted: 01 Jun 2025 — Issue date: 06 Jun 2025
MOPS016
Multi-objective optimisation of the Diamond-II storage ring optics
605
The design performance of the 3.5 GeV Diamond-II low-emittance electron storage ring has been studied as a function of the linear and nonlinear lattice tuning parameters. A Multi-Objective Genetic Algorithm (MOGA) has been implemented to optimise both the beam lifetime and the injection efficiency for off-axis injection. The simulations have been run on 5 machine error seeds, including misalignment and field strength errors, to obtain a solution which is robust against machine imperfections. The results of the optimisation are presented alongside a comparison of the baseline performance.
Paper: MOPS016
DOI: reference for this paper: 10.18429/JACoW-IPAC25-MOPS016
About: Received: 28 May 2025 — Revised: 30 May 2025 — Accepted: 01 Jun 2025 — Issue date: 06 Jun 2025
MOPS017
Further progress with alternative optics for the Diamond-II storage ring upgrade
609
We report the progress made on alternative optics namely low beta and low emittance cases for the DIAMOND-II storage ring upgrade. The results of optimizations of both linear and nonlinear optics as well as impacts of insertion devices on lifetime and dynamic aperture and injection scenarios will be reported.
Paper: MOPS017
DOI: reference for this paper: 10.18429/JACoW-IPAC25-MOPS017
About: Received: 23 May 2025 — Revised: 30 May 2025 — Accepted: 01 Jun 2025 — Issue date: 06 Jun 2025
MOPS018
Demonstrating the feasibility of a double-crystal fixed-target experimental physics setup through the TWOCRYST project in the LHC
613
The TWOCRYST proof-of-principle experiment at the LHC is an initiative to demonstrate the feasibility of a double-crystal setup for fixed-target physics experiments. Such a setup could enable spin precession studies of charmed baryons in the TeV energy range in the HL-LHC era. Major milestones in this project have recently been achieved, including the successful construction and testing of critical components such as the 4~mm and 7~cm long bent silicon crystals required, a new combined fixed-target and crystal goniometer for accurate angular positioning, and two Roman pot stations equipped with advanced tracking detectors. This contribution summarizes the status of the hardware, the results from the first machine development studies to prepare for the measurements with the crystals in 2025, and a detailed plan for the beam tests with the full TWOCRYST setup.
Paper: MOPS018
DOI: reference for this paper: 10.18429/JACoW-IPAC25-MOPS018
About: Received: 19 May 2025 — Revised: 03 Jun 2025 — Accepted: 04 Jun 2025 — Issue date: 06 Jun 2025
MOPS019
Simulated beam performance of the TWOCRYST proof of principle experiment at the LHC
617
TWOCRYST is a machine test designed to demonstrate the feasibility of an in-vacuum fixed-target experiment for the first direct measurement of the magnetic and electric dipole moments of short-lived charm baryons. This setup exploits crystal channeling using two bent crystals. The first one is similar to the existing crystals used in the LHC for beam collimation, deflecting the beam halo particles from the proton beam onto a target. The second one - a 7 cm silicon crystal - induces spin precession in the secondary particles produced in the target. 2D detectors in movable Roman pots will track the distribution of these channeled particles. A new silicon pixel detector and a fiber tracker (formerly used by the LHC ATLAS-ALFA experiment) are planned for installation in the LHC along with the two crystals in early 2025. Xsuite simulations have been performed to reproduce the multi-turn beam dynamics of the channeled beam halo and the particle distribution expected at the detectors. The LHC configurations required for the planned measurements have also been simulated, with the results used to specify the required detector performance in preparation for benchmarking against real data.
Paper: MOPS019
DOI: reference for this paper: 10.18429/JACoW-IPAC25-MOPS019
About: Received: 20 May 2025 — Revised: 30 May 2025 — Accepted: 30 May 2025 — Issue date: 06 Jun 2025
MOPS020
The TWOCRYST fibre tracker: A detector to characterize precession crystals at the LHC
621
A fixed-target experiment using two bent crystals is proposed to study the magnetic and electric dipole moments of short-lived charm baryons with unprecedented precision in the LHC. This will be achieved exploiting crystal channeling into a first crystal to extract the beam halo and then into a 7 cm long silicon crystal capable of inducing a measurable spin precession to the particles of interest. TWOCRYST is a proof-of-principle machine test scheduled for 2025, to test this setup and address the feasibility of the final experiment under LHC beam conditions. One main goal is the study of the channeling efficiency in this long crystal at TeV energies, requiring a 2D detector in movable Roman pots. The TWOCRYST Fibre Tracker, coming from the LHC's ATLAS-ALFA experiment, is a high-precision tracking detector with ten layers of crossing scintillating fibers coupled to multi-anode photomultipliers, and read out using compact front-end electronics. Intense refurbishment work was required on to adapt the detector to the purposes of TWOCRYST. This contribution summarizes the tracker specifications as derived from beam dynamics simulations and the results of tests prior to its installation.
Paper: MOPS020
DOI: reference for this paper: 10.18429/JACoW-IPAC25-MOPS020
About: Received: 20 May 2025 — Revised: 30 May 2025 — Accepted: 30 May 2025 — Issue date: 06 Jun 2025
Status and performance of LumiBelle2 in the 2025 beam operation of SuperKEKB
LumiBelle2 is a fast luminosity monitor used for beam parameter tuning and feedback at the interaction point of SuperKEKB. It uses sCVD diamond detectors placed in both the electron and positron rings to measure the rates of single bremsstrahlung events. Luminosity signals are provided both for averaging all bunches and for each bunch crossing at 1 Hz. The averaged luminosity signal over all bunches is also provided at 1 kHz as input to a dithering feedback system used to maintain optimum overlap between the colliding beams in the horizontal plane. In 2025, new LGAD sensors will be tried as potential alternative to the sCVD diamond sensors. This paper will describe the overall status and performance of LumiBelle2 in the Autumn 2024 and Winter 2025 SuperKEK operation, as well as report on the tests with the new LGAD sensors.
MOPS022
Investigation on injection-related beam loss at SuperKEKB
625
The current achieved highest luminosity at SuperKEKB is only one-tenth of the design value, and beam injection is one of the most serious issues in achieving the target luminosity. Recent operations in both the HER and LER rings have shown insufficient injection efficiencies and detector backgrounds. The achieved injection efficiency falls short of the required level, sometimes leading to difficulties in injecting the beam at high current values. Following each injection, significant signals from particle losses are detected in several Belle II detector components, particularly the vertex detector, resulting in saturating the data acquisition with a dead time exceeding 10ms. The complexity of the injection, and critical factors like injected beam quality, beam lifetime, dynamic aperture, machine errors, nonlinearity, as well as the collimation system, makes the optimization challenging. Detailed injection simulations are essential to understand the issues of the injection and guide adjustments to maximize the injection efficiency and mitigate the injection background. This paper presents the findings of HER injection simulations and their experimental validation.
Paper: MOPS022
DOI: reference for this paper: 10.18429/JACoW-IPAC25-MOPS022
About: Received: 28 May 2025 — Revised: 02 Jun 2025 — Accepted: 06 Jun 2025 — Issue date: 06 Jun 2025
MOPS023
Design of the front-end complex for a muon cooling demonstrator at CERN
629
The muon collider has great potential for enabling high-luminosity multi-TeV lepton-antilepton collisions provided low-emittance, high-intensity muon beams can be produced. Ionization cooling is the proposed technique to achieve the required muon beam emittance. The International Muon Collider Collaboration aims to demonstrate the integration and reliable operation of a 6D ionization cooling system, including RF acceleration in strong magnetic fields. This study focuses on the design of the muon production and transport systems for a Muon Cooling Demonstrator facility in the CERN TT7 tunnel. A new implementation based on the CTF3 building is also presented, offering improved layout flexibility and beam intensity. FLUKA simulations are used to optimize the target and magnetic horn geometries to maximize pion production and capture, assuming a 14 GeV proton beam from the Proton Synchrotron (PS). The transport line, designed to deliver 190 – 210 MeV/c muons into the cooling channel, consists of a short pion decay section, followed by a momentum-selecting chicane and a matching section. The chicane integrates collimation and phase-rotation systems for transverse and longitudinal tuning of the muon beam. Beam optics for the transport lattice are designed in MAD-X, with tracking studies performed using BDSIM.
Paper: MOPS023
DOI: reference for this paper: 10.18429/JACoW-IPAC25-MOPS023
About: Received: 28 May 2025 — Revised: 04 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 06 Jun 2025
MOPS024
Implementation and simulation of a rectilinear cooling channel in BDSIM
633
Muon colliders offer high-luminosity, multi-TeV collisions without significant synchrotron radiation but require further exploration of muon production, acceleration, cooling, and storage techniques. A proposed 6D cooling demonstrator aims to extend the MICE experiment's validation of transverse ionization cooling to also reduce longitudinal emittance, using bunched muon beams and incorporating RF cavities for reacceleration. The cooling lattice includes solenoids for tight focusing, dipoles for beam dispersion, and wedge absorbers for differential energy loss. This paper presents a complete implementation of cooling channels for BDSIM, a Geant4-based accelerator simulation tool, using appropriate analytic field models to account for fringe-field-dominated magnets. Components have been tested individually and validated against other tracking codes such as G4BeamLine. A tracking study leveraging this implementation is presented, simulating and optimizing a rectilinear cooling channel for the 6D cooling demonstrator. The analysis incorporates beam parameters from existing proton drivers, using outputs from targetry and capture system designs.
Paper: MOPS024
DOI: reference for this paper: 10.18429/JACoW-IPAC25-MOPS024
About: Received: 25 May 2025 — Revised: 02 Jun 2025 — Accepted: 04 Jun 2025 — Issue date: 06 Jun 2025
MOPS025
Simulation studies and design updates for the nuSTORM facility
637
The neutrinos from Stored Muons (nuSTORM) experiment aims to create neutrino beams through muon decay in a storage ring, targeting %-level precision in flux determination. With access to two neutrino flavors, it enables precise measurement of $\nu$-A cross sections and exhibits sensitivity to Beyond Standard Model (BSM) physics. With muons in the 1-6 GeV/c momentum range, it covers neutrino energy regimes relevant to experiments like DUNE and T2HK. Additionally, nuSTORM serves as a step towards a muon collider, a proof of concept for storage rings, and a testbed for beam monitoring and magnet technologies. The lattice structure consists of a pion transport line and a racetrack storage ring based on a hybrid FFA design, with conventional FODO cells in the production straight combined with FFA cells in the return straight and arcs. This paper provides an update on the nuSTORM design and simulation efforts. It covers horn and lattice optimizations for producing and storing low-energy muons, describes tracking studies of the lattice to guide event normalization and presents the latest simulated neutrino fluxes.
Paper: MOPS025
DOI: reference for this paper: 10.18429/JACoW-IPAC25-MOPS025
About: Received: 28 May 2025 — Revised: 03 Jun 2025 — Accepted: 04 Jun 2025 — Issue date: 06 Jun 2025
The correction of beam trajectory for low energy injector
High-brightness and high-average current electron sources with excellent beam quality hold significant potential for applications in fields such as ultrafast electron diffraction (UED), free-electron lasers (FELs), and energy recovery linacs (ERLs). However, when the electron beam is initially generated, it typically exhibits large energy spread, beam size, and relatively low energy. During beam transport, it is highly susceptible to stray magnetic fields, which can lead to angular and positional deviations as the beam passes through magnets or microwave acceleration structures, ultimately degrading beam quality. This article focuses on the recent progress in low-energy beam commissioning of the SHINE injector.
MOPS027
Preliminary results from the CLEAR nonlinear plasma lens experiment
641
Plasma lensing provides compact focusing of electron beams, since they offer strong focusing fields (kT/m) in both planes simultaneously. This becomes particularly important for highly diverging beams with a large energy spread such as those typically originating from plasma accelerators. The lens presented here is a nonlinear active plasma lens, with a controlled focusing-strength variation purposely introduced in one transverse direction. This lens is a key element of a larger transport lattice, core of the ERC project SPARTA, which aims to provide a solution for achromatic transport between plasma-accelerator stages. We report on preliminary experimental results from the CLEAR facility at CERN, which aims to probe the magnetic field structure of the lens using an electron beam, in search of the desired nonlinearity, together with 2D plasma simulation results.
Paper: MOPS027
DOI: reference for this paper: 10.18429/JACoW-IPAC25-MOPS027
About: Received: 27 May 2025 — Revised: 04 Jun 2025 — Accepted: 04 Jun 2025 — Issue date: 06 Jun 2025
MOPS028
Preparing the future SPS fixed target beams for the SHiP experiment
645
A new high-intensity Beam Dump Facility (BDF), hosting the SHiP (Search of Hidden Particles) experiment, is set to begin operation in CERN’s North Area (NA) in Run 4. To meet its physics goals, SHiP aims at accumulating 4$\times$10$^{19}$ protons on target per year, which will require approximately 10$^6$ high intensity cycles from the SPS with $4.2\times10^{13}$ p$^+$ per cycle (as operationally used during the CNGS era) over a $1$ s spill length. To reduce the future supercycle load and thus minimize the impact on the other physics facilities (especially at the CERN PS complex delivering the beam to the SPS), a strategy involving higher intensity per spill but a smaller number of spills for SHiP was proposed. In this context, a series of studies have been initiated to explore the intensity limits of the North Area beams in the SPS. This contribution presents the initial results on the correction of the intensity dependent tune shift induced by the beam coupling impedance and the transverse optimizations required for operating at higher intensities.
Paper: MOPS028
DOI: reference for this paper: 10.18429/JACoW-IPAC25-MOPS028
About: Received: 26 May 2025 — Revised: 30 May 2025 — Accepted: 31 May 2025 — Issue date: 06 Jun 2025
MOPS029
High Luminosity LHC collimation system performance for different optics configurations
649
The High Luminosity Large Hadron Collider (HL-LHC) presents significant collimation challenges due to its high stored beam energy. An effective collimation system is critical for ensuring stable operation, protecting the superconducting magnets and minimizing background to the experiments. This paper examines the current baseline collimation configuration and potential changes to the collimation insertion optics to improve the performance in various areas, for both proton and heavy ion beam operation. The study encompasses on- and off-momentum beam loss simulations across various stages of the operational cycle. Collimation performance is assessed based on leakage to superconducting magnets, as well as losses on the tertiary collimators, to probe this source of induced background to the experimental detectors.
Paper: MOPS029
DOI: reference for this paper: 10.18429/JACoW-IPAC25-MOPS029
About: Received: 28 May 2025 — Revised: 31 May 2025 — Accepted: 01 Jun 2025 — Issue date: 06 Jun 2025
MOPS030
Xcoll-BDSIM coupling for beam collimation
653
Xsuite is a comprehensive simulation toolkit for accelerator physics, with Xcoll serving as the dedicated module for collimation studies. These studies involve tracking particles through an accelerator and simulating their interactions with matter, taking into account non-linear elements and large betatron and off-momentum deviations. Particle-matter interactions can be modeled using an internal scattering model, Everest, or coupled to external codes. This paper presents the integration of Xcoll with the Geant4 libraries by utilizing the Beam Delivery Simulation (BDSIM) code. This coupling enables efficient tracking of diverse particle species through materials, along with realistic simulations of energy deposition and secondary particle production. The implementation is designed to be flexible, supporting the inclusion of detailed collimator geometries, beam-gas interactions, and crystal channeling effects.
Paper: MOPS030
DOI: reference for this paper: 10.18429/JACoW-IPAC25-MOPS030
About: Received: 28 May 2025 — Revised: 31 May 2025 — Accepted: 02 Jun 2025 — Issue date: 06 Jun 2025
MOPS031
Preliminary results of crystal channelling optimisation in the LHC using reinforcement learning
657
The Large Hadron Collider (LHC) can operate with high intensity proton and heavy ion beams, both of which require a collimation system to ensure an efficient operation and to protect against damage to sensitive equipment along the ring. The crystal collimation scheme using bent silicon crystals as primary collimators was therefore introduced to improve the collimation efficiency for heavy ion-beams. The first operational deployment of crystal-assisted collimation was achieved in the 2023 Pb run. This demonstrated the required performance gain to safely handle high intensity ion beams, but undesired crystal rotation led to the loss of optimal performance during physics fills. The cause of this is thought to be mechanical deformation of the goniometer due to heating related to beam impedance effects. Hence, a conventional numerical optimiser was deployed to monitor and compensate for crystal angular errors based on a set of beam-loss monitors. The problem at hand, allows for the use of machine learning techniques to ensure continuous optimal channelling, minimising convergence time and eventually the optimization of crystals in multiple planes in parallel.
Paper: MOPS031
DOI: reference for this paper: 10.18429/JACoW-IPAC25-MOPS031
About: Received: 24 May 2025 — Revised: 03 Jun 2025 — Accepted: 03 Jun 2025 — Issue date: 06 Jun 2025
MOPS032
Operational deployment of automatic angular alignment for LHC collimators
661
The Large Hadron Collider (LHC) features a collimation system that protects the machine against beam losses that may induce the loss of superconductivity in some exposed lattice magnets. Thus, optimal cleaning performance must be ensured at all times. The collimation system encompasses more than 100 collimators whose settings are organised in a well-defined transverse multi-stage hierarchy. A collimator alignment toolset has been developed over the years to automate the alignment of the system during beam commissioning. During alignment, the collimator jaws used to be kept parallel to the central beam orbit. However, further tightening of the collimation hierarchy to improve the β* reach is only possible if the collimator jaw angles are precisely adjusted to compensate for any mechanical or orbit tilts. Advanced alignment procedures have therefore been developed to compensate for these effects. The first operational deployment of jaw angle has been achieved in the 2024 run. The commissioning results leading to this milestone are reported in this paper, together with the optimisation of parallel jaw alignment and an overview of the operational architecture.
Paper: MOPS032
DOI: reference for this paper: 10.18429/JACoW-IPAC25-MOPS032
About: Received: 23 May 2025 — Revised: 01 Jun 2025 — Accepted: 03 Jun 2025 — Issue date: 06 Jun 2025
MOPS034
Increasing single-bunch intensity limit at ESRF-EBS with high coupling
665
Synchrotron radiation light sources normally operate at a low coupling between the transverse planes in order to achieve flat beams and produce high peak brilliance. Instead, operating at a high coupling has other advantages such as smaller emittance degradation due to intra-beam scattering, improved Touschek lifetime, and lower sensitivity to vibrations of the photon beam. Moreover, it has been suggested that a high coupling may enable achieving higher bunch currents thanks to sharing of the beam-induced wakefields between the transverse planes. We were able to take advantage of this effect to substantially increase the TMCI threshold at zero chromaticity and nearly double the single bunch current limit at high chromaticity at ESRF-EBS.
Paper: MOPS034
DOI: reference for this paper: 10.18429/JACoW-IPAC25-MOPS034
About: Received: 14 May 2025 — Revised: 04 Jun 2025 — Accepted: 04 Jun 2025 — Issue date: 06 Jun 2025
MOPS035
Space charge limit for light sources
668
With the adoption of multi-bend achromat lattices and the aim for diffraction limit, the state-of-the-art light sources are approaching a point where their emittance becomes so small that the effects of space charge can no longer be ignored. Space charge produces a significant betatron tune spread that affects many aspects of beam dynamics: single particle dynamics to collective beam stability. But most importantly, space charge imposes a fundamental limit to the ultimate beam brightness that can be achieved in a synchrotron light source. We demonstrate that the only way to increase the beam brightness and therefore the photon brilliance further is to opt for a higher beam energy.
Paper: MOPS035
DOI: reference for this paper: 10.18429/JACoW-IPAC25-MOPS035
About: Received: 06 May 2025 — Revised: 29 May 2025 — Accepted: 29 May 2025 — Issue date: 06 Jun 2025
MOPS036
Development of a pulsed magnet measurement bench using the stretched wire method
672
In the scope of the renewal of its injection systems, the ESRF-EBS has decided to implement a new scheme using Non-Linear Kickers (NLK) magnets. These pulsed octupole like magnets are extremely sensitive to any misalignment of the conductors carrying the currents resulting in a degraded magnetic field quality. It is then important to characterize precisely the transverse magnetic fields of these magnets to avoid any perturbation during the injection process. A new method to measure pulsed magnetic field is being developed at the ESRF-EBS readapting the classical method of the stretch wire bench for permanent magnet. This paper presents the advancement of this project and the first results.
Paper: MOPS036
DOI: reference for this paper: 10.18429/JACoW-IPAC25-MOPS036
About: Received: 27 May 2025 — Revised: 02 Jun 2025 — Accepted: 03 Jun 2025 — Issue date: 06 Jun 2025
MOPS038
Simulations of bunch length reduction techniques in the SLS booster
676
Modern injection schemes for light sources seek to explore the full 6D phase space in order to find creative ways of top-up injection with minimal perturbation to the stored beam. The longitudinal injection scheme is considered for the SLS 2.0 storage ring and, hence, the longitudinal profile of the injected beam becomes highly relevant for the injection efficiency. We simulate possible ways of reducing the bunch length in the SLS booster synchrotron. The feasibility of increasing the total RF voltage by installing additional or different RF cavities is considered. Furthermore, we simulate the impact of pulsed- or oscillating RF voltages and phases in order to compress the beam longitudinally at the expense of an increased energy spread.
Paper: MOPS038
DOI: reference for this paper: 10.18429/JACoW-IPAC25-MOPS038
About: Received: 28 May 2025 — Revised: 04 Jun 2025 — Accepted: 04 Jun 2025 — Issue date: 06 Jun 2025
MOPS039
Direct MOGA optimization of touschek lifetime and dynamic aperture using fast touschek tracking
680
A large momentum acceptance (MA) in 4th generation storage ring light sources is paramount to obtaining a long Touschek lifetime. However, the calculation of MA typically requires computationally expensive tracking simulations thereby complicating, or even disabling, the direct optimization of Touschek lifetime using numerical optimization algorithms. Our recent development of Fast Touschek Tracking allows obtaining the MA two orders of magnitude faster than standard MA tracking, thereby enabling direct optimization of Touschek lifetime. We present an example of a Multi-Objective Genetic Algorithm (MOGA) optimization of both on-energy dynamic aperture and direct Touschek lifetime using Fast Touschek Tracking for a 4th generation storage ring.
Paper: MOPS039
DOI: reference for this paper: 10.18429/JACoW-IPAC25-MOPS039
About: Received: 28 May 2025 — Revised: 03 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 06 Jun 2025
MOPS040
Start to end commissioning simulations for SOLEIL II storage ring
684
This paper presents comprehensive start-to-end commissioning simulations for the SOLEIL II storage ring upgrade, demonstrating the feasibility of achieving an ultra-low emittance of 84 pm-rad at 2.75 GeV. We detail a multi-step correction strategy addressing challenges posed by the dense magnet arrangement and limited number of BPMs and correctors. Our simulations encompass first turn trajectory correction, beam-based alignment (BBA), and Linear Optics from Closed Orbit (LOCO) techniques. Results demonstrate the robustness of the correction scheme in the presence of realistic errors, showing successful recovery of design emittance, suitable dynamic aperture, and expected beam lifetime. This work provides insights into an efficient commissioning strategy for SOLEIL II, supporting rapid commissioning and full performance restoration for user operations.
Paper: MOPS040
DOI: reference for this paper: 10.18429/JACoW-IPAC25-MOPS040
About: Received: 27 May 2025 — Revised: 05 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 06 Jun 2025
MOPS041
Status of the beam dynamics studies for the PERLE Energy Recovery Linac
688
PERLE (Powerful Energy Recovery Linac for Experiments) is a three-turn, high power Energy Recovery Linac under construction at IJCLab, France. It emerged from the design of the LHEC and FCC-eh and will serve as a hub for the validation of several technical choices and exploration of a broad range of accelerator phenomena in an unexplored operational power regime (up to 10 MW in its final version). Up to now, the final lattice design and phasing has been finalised. Current studies focus on non-linear effects and longitudinal dynamics. Also, the commissioning scheme is under developpement. We will present the status of the beam dynamics studies of the project, and highligth some of the ongoing studies
Paper: MOPS041
DOI: reference for this paper: 10.18429/JACoW-IPAC25-MOPS041
About: Received: 28 May 2025 — Revised: 03 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 06 Jun 2025
MOPS043
ALBA II accelerator upgrade project status
692
ALBA is working on the upgrade project that shall transform the actual storage ring, in operation since 2012, into a 4th generation light source, in which the soft X-rays part of the spectrum shall be diffraction limited. The project was launched in 2021 with an R&D budget to build prototypes of the more critical components. The storage ring upgrade is based on a MBA lattice which has to comply with several constraints imposed by the decision of maintaining the same circumference (269m), the same number of cells (16), the same beam energy (3GeV), and as many of the source points as possible unperturbed. At present, the lattice optimization, iterating with the technical constraints of space and performance, is ongoing. This paper presents the situation of the project, with the present proposed lattice and equipment design; the status of the prototyping of magnets, pulsed elements. vacuum chambers, buttons BPMs, and girders; the proposed RF system with fundamental and harmonics cavities; and the general context of the upgrade.
Paper: MOPS043
DOI: reference for this paper: 10.18429/JACoW-IPAC25-MOPS043
About: Received: 26 May 2025 — Revised: 03 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 06 Jun 2025
Vertical emittance control with a beam shaker for PETRA IV
As an option to control the vertical emittance a beam shaker will be implemented at the planned upgrade of the synchrotron light source at DESY, Hamburg. We evaluate the electron beam dynamics for a simple sine-wave and a noise band excitation and present the expected equilibrium vertical emittances.
MOPS045
Considerations of a round beam operation at PETRA IV
696
Round beam operation is considered for the planned ultra-low emittance storage ring PETRA IV at DESY, Hamburg. With a natural emittance of 20 pm rad, we evaluate and discuss the advantages and challenges of sharing the emittance between transversal planes. The effect on single and coupled bunch instability thresholds, intra-beam scattering rates and Touschek lifetime of this operation mode are presented.
Paper: MOPS045
DOI: reference for this paper: 10.18429/JACoW-IPAC25-MOPS045
About: Received: 26 May 2025 — Revised: 01 Jun 2025 — Accepted: 02 Jun 2025 — Issue date: 06 Jun 2025
MOPS046
Beam loading for counter-rotating high-intensity beams in the Muon collider
700
Muon colliders promise an efficient path to a multi-TeV energy collider facility. In the greenfield study, the final stage of the acceleration chain is planned as a series of four rapid-cycling synchrotrons (RCS). In each RCS, the RF systems are divided into several sections and shared by the two counter-rotating muon bunches. The accelerator requirements are driven by the need to preserve a maximum number of muons by taking advantage of time dilation. Therefore, maintaining a high accelerating voltage throughout the chain is essential, imposing superconducting RF cavities in the GV range. However, the high bunch intensity of up to $2.7\times 10^{12}$ particles per bunch and the 1.3 GHz TESLA cavity’s small aperture will result in induced voltages in the MV range. In the muon collider, the induced voltage of the counter-rotating beams will additionally impact the cavity voltage. This contribution presents the cavity voltage modulation and its impact on the beam loss and stability in the strong transient beam loading regime.
Paper: MOPS046
DOI: reference for this paper: 10.18429/JACoW-IPAC25-MOPS046
About: Received: 27 May 2025 — Revised: 04 Jun 2025 — Accepted: 04 Jun 2025 — Issue date: 06 Jun 2025
MOPS047
Development of new ion beams at the CERN ion injector complex for future physics programmes
704
In an effort driven by the requests from different physics experiments at CERN, the CERN ion injector complex is looking to expand its capabilities by providing lighter-than-lead ion beams. Argon and xenon were delivered for NA61/SHINE physics in 2015 and 2017, with xenon also reaching the LHC in 2017. Oxygen is foreseen to be collided in the LHC in 2025, with magnesium, boron and krypton beams also being prepared. Before new ion species can be considered operational for experiments, the feasibility of producing and accelerating these beams throughout the accelerator complex has to be assessed. This contribution presents an overview of the performance of the ion complex with recently tested magnesium ion beams, the latest results of the ongoing oxygen beam commissioning, and future plans concerning ion species that still need to be developed.
Paper: MOPS047
DOI: reference for this paper: 10.18429/JACoW-IPAC25-MOPS047
About: Received: 02 Apr 2025 — Revised: 03 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 06 Jun 2025
MOPS048
First options for an ESRF EBS upgrade lattice
708
A new lattice for the EBS is proposed as preliminary candidate for the next generation ESRF storage ring. This new optics would feature lower emittance, matched optics at all ID, transparency conditions for insertions and overall a net gain in brilliance coherence and flux. Due to the reduced dynamic aperture, on-axis injection with a low emittance beam would be a requirement in order to progress with these optics.
Paper: MOPS048
DOI: reference for this paper: 10.18429/JACoW-IPAC25-MOPS048
About: Received: 27 May 2025 — Revised: 04 Jun 2025 — Accepted: 04 Jun 2025 — Issue date: 06 Jun 2025
MOPS049
Beam loss scenarios for the SOLEIL II upgrade
712
SOLEIL II is an ambitious upgrade project that aims to reduce the horizontal emittance of the SOLEIL facility from 4 nm to 84 pm (to be further reduced to 50 pm by running with round beams). The SOLEIL II lattice will utilise a combination of permanent magnets and electro-magnetic corrector magnets. In the case of beam losses, it is of critical importance to localise the losses to certain shielded areas or dedicated collimators in order to prevent the risk of demagnetisation of the permanent magnets. The study and development of different beam loss scenarios will be presented.
Paper: MOPS049
DOI: reference for this paper: 10.18429/JACoW-IPAC25-MOPS049
About: Received: 27 May 2025 — Revised: 30 May 2025 — Accepted: 03 Jun 2025 — Issue date: 06 Jun 2025
MOPS051
Light upgrade of the ESRF booster
716
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: 06 Jun 2025
MOPS052
Overview of ESRF-EBS's four-year operation and strategy for further upgrade
719
The user operation of the Extremely Brilliant Source (EBS) since August 2020 has opened a new era of high energy fourth generation synchrotron radiation light sources. During the following four years of operation, the EBS accelerator has sustained user operation with high availability, reliability, and stability, and has continued to improve beam performance by reducing injection perturbations, increasing bunch/beam currents for different beam delivery modes, and consolidating the storage ring operation with a hot-swap power supply system, newly designed kicker ceramic chambers, etc. Sustainability has always been key to EBS operation and future upgrades. During user operation, measures on the RF system of the storage ring and HQPS operation have been implemented to save power consumption; in the near future, solid-state amplifiers and 4th harmonic RF system projects will ensure the sustainability of machine operation further. In addition, as a strategy for future upgrades of the EBS accelerator complex, injector upgrades are being considered, including the injection with a new linac, which can be further upgraded to inject full-energy beam into the storage ring.
Paper: MOPS052
DOI: reference for this paper: 10.18429/JACoW-IPAC25-MOPS052
About: Received: 29 May 2025 — Revised: 02 Jun 2025 — Accepted: 04 Jun 2025 — Issue date: 06 Jun 2025
MOPS053
Applications of electron energy measurement based on resonant spin depolarization at BESSY II
723
An electron energy measurement based on resonant spin depolarization has been running permanently at BESSY II for several years. This high-precision energy measurement was set up primarily for users of synchrotron radiation for me- teorological applications from the Physikalisch-Technische Bundesanstalt (PTB). Recent investigations have led to a better understanding of the method and the possibility of shortening the measurement time. This allows for new obser- vations and the use of the energy measurement for different applications such as the model-free measurement of the natural chromaticity, the momentum compaction factor or synchrotron sidebands.
Paper: MOPS053
DOI: reference for this paper: 10.18429/JACoW-IPAC25-MOPS053
About: Received: 27 May 2025 — Revised: 31 May 2025 — Accepted: 03 Jun 2025 — Issue date: 06 Jun 2025
MOPS055
Magnet assembly of IVUE32 in-vacuum-APPLE II at BESSY II
727
At HZB / BESSY II the first in-vacuum APPLE II undu-lator is under construction. The design includes three magnet arrays for each of the four magnet rows for an efficient force compensation. The support and drive sys-tem has been delivered. Currently the magnets for the 10-period prototype are fabricated by Vacuumschmelze. Within the project IVUE32 a new soldering technique based on reactive foils has been developed in collabora-tion with Vacuumschmelze. The magnet structure of the IVUE32 undulator will employ the soldering technique aiming for enhanced assembly simplicity. Two new ex-perimental setups for the characterization of soldered subassemblies have been built for obtaining stress-strain curves and for lifetime (fatigue) tests. These instruments will be presented and measurements will be discussed.
Paper: MOPS055
DOI: reference for this paper: 10.18429/JACoW-IPAC25-MOPS055
About: Received: 19 May 2025 — Revised: 04 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 06 Jun 2025
MOPS056
Single electron storage at UVSOR-Ⅲ electron storage ring
731
We have started single electron storage experiments since 2021 at the UVSOR-Ⅲ storage ring with the aim of conducting fundamental research on electromagnetic radiation. At BL1U, which is a beamline dedicated to light source developments, we extracted undulator light in the UV wavelength range into the air and observed its intensity by a photomultiplier tube, as decreasing the electron beam intensity using a beam scraper. When the beam intensity became sufficiently small, we observed step-function-like intensity changes with a good SN ratio, each of which corresponded to a loss of one electron. Based on this technique, we confirmed the single electron storage. After establishing the technique, we conducted some experimental studies on undulator radiation from single electron. We will present the latest results at the conference.
Paper: MOPS056
DOI: reference for this paper: 10.18429/JACoW-IPAC25-MOPS056
About: Received: 28 May 2025 — Revised: 02 Jun 2025 — Accepted: 03 Jun 2025 — Issue date: 06 Jun 2025
Manufacturing, assembly and construction progress of the ALS-U project to create a soft x-ray diffraction limited light source
The ALS-U project, aimed at enhancing the Advanced Light Source’s capabilities, is currently in the manufacturing, assembly, and construction phases. The construction of the accumulator, a crucial component, is nearing completion, with commissioning expected towards next year. ALS-U promises to deliver diffraction-limited performance in the soft x-ray range by significantly reducing the horizontal emittance to approximately 70 pm rad. This achievement will result in a remarkable two orders of magnitude brightness increase for soft x-rays compared to the current ALS. The design incorporates a nine-bend achromat lattice, featuring reverse bending magnets and on-axis swap-out injection utilizing an accumulator ring. This optimized design is specifically tailored to generate intense beams of soft x-rays, which possess spectroscopic contrast, nanometer-scale resolution, and broad temporal sensitivity. This paper provides an overview of the project’s design features and offers an update on the progress made in manufacturing, assembly, and testing.
Physics design progress of the HALF project
The Hefei Advanced Light Facility (HALF), a soft X-ray and VUV diffraction-limited storage ring light source, started construction in 2023. This paper describes the physics design progress of the HALF storage ring over the past year.
MOPS060
Undulators for BESSY III
734
Helmholtz Zentrum Berlin is engaged in the conceptual design of the BESSY III facility. The BESSY III storage ring will be a fourth generation synchrotron light source with an emittance of about 100 pm rad and an energy of 2.5 GeV. It will be equipped with advanced undulators to provide users with tailor-made light. So far cryogenic permanent magnet undulators, hybrid planar undulators and a variety of APPLE II undulators - conventional (in-air) and in-vacuum are planned to meet user requirements in terms of spectral range, flux and polarisation. In this paper we give an overview of the planned undulators, discuss some of the design aspects and present their expected performance.
Paper: MOPS060
DOI: reference for this paper: 10.18429/JACoW-IPAC25-MOPS060
About: Received: 25 May 2025 — Revised: 01 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 06 Jun 2025
MOPS061
MAX 4U: an upgrade of the MAX IV 3 GeV ring
738
The MAX IV 3 GeV storage ring in Lund, Sweden, was the first implementation of a multibend achromat (MBA) lattice fourth-generation light source. Since it started delivery of light in 2016, three succeeding MBA-based rings and variants have come on-line: ESRF-EBS, Sirius and APS-U. Several others are being planned, designed, built or commissioned. All of these capitalize on the MBA concept and expand it to push the brightness and coherence performance even further. In order to continue to offer the Swedish and international scientific communities competitive tools beyond the end of this decade, MAX IV Laboratory launched in 2024 the conceptual design of MAX 4U , an upgrade of its 3 GeV storage ring aiming at an emittance below 100 pmrad. This performance boost is to be achieved through a minimum-interference upgrade in which localized interventions in selected subsystems and components are carefully chosen to provide the maximum performance increase with minimum cost and, equally important, minimum dark time for the MAX IV user community. This contribution describes the accelerator physics and engineering aspects of the MAX 4U conceptual design and presents the latest developments.
Paper: MOPS061
DOI: reference for this paper: 10.18429/JACoW-IPAC25-MOPS061
About: Received: 21 May 2025 — Revised: 03 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 06 Jun 2025
Science at the RIXS beamline at MAX IV Laboratory
Here I will showcase the advanced precision instrumentations involved at the Veritas beamline dedicated to high resolution soft X-ray resonant inelastic X-ray scattering (RIXS) experiments. Following this, I will unveil the unique science cases one can attempt here.
MOPS063
10 years operation of the Solaris storage ring
742
The SOLARIS storage ring, Poland’s first synchrotron light source, has marked a decade of successful operation, contributing significantly to scientific research and technological advancement. Commissioned in 2015 and inspired by the innovative design of Sweden’s MAX IV Laboratory, SOLARIS exemplifies the effectiveness of international collaboration in cutting-edge accelerator technologies. Over the past 10 years, the facility has maintained high performance and reliability (97% availability), delivering high-quality photon beams to researchers in diverse fields. Continuous improvements in the accelerator systems, such as enhanced beam stability due to SOFB and FOFB implementation, and optimised maintenance schedules, have enabled SOLARIS to meet the growing demands of the scientific community. A key focus has been the development of new beamlines and experimental stations, broadening the scope of available research capabilities. Looking ahead, SOLARIS aims to further expand its infrastructure (linac upgrade, top-up injection) and enhance beamline performance, ensuring its continued role as a hub for innovation and scientific excellence.
Paper: MOPS063
DOI: reference for this paper: 10.18429/JACoW-IPAC25-MOPS063
About: Received: 28 May 2025 — Revised: 30 May 2025 — Accepted: 31 May 2025 — Issue date: 06 Jun 2025
X-ray beam position monitor with pixelated GaAs detectors for high-power synchrotron radiation beams
A novel soft X-ray BPM (sXBPM) for high-power beams of synchrotron undulator radiation has been developed through a joint effort by BNL/NSLS-II and Stony Brook University. In this approach, custom-made multi-pixel GaAs detector arrays are positioned in the outer portions of the X-ray beam, with beam position inferred from the pixel photocurrents. The first R&D device was installed in the 23-ID canted undulator beamline of NSLS-II, about 27 m downstream of the canted EPU source, and ahead of any beamline elements (i.e. in white beam). The device has demonstrated sub-micron positional resolution without interfering with user experiments, including the most sensitive ones exploiting the beam's coherent properties. Beyond positional measurements, the sXBPM effectively monitors the beam's cross-sectional shapes at the detector array locations. Due to movable detectors, the sXBPM can also capture complete 2D cross-sections of the X-ray beam when beam interception is permitted. This paper reviews the sXBPM design and highlights the latest experimental results, demonstrating why this approach is well-suited for XBPMs in future light sources with highly coherent X-ray beams.
MOPS065
Physics-driven specifications for the EIC ESR magnet power supply ripple
746
To avoid unacceptable proton emittance growth via beam-beam interaction, the EIC electron storage ring (ESR) requires very stringent tolerances for beam position and size stability at the interaction point. These tolerances imply tight specifications for several accelerator systems, including magnet power supplies (PS). While the magnetic field ripple requirements are most stringent at the betatron frequency and harmonics, the main PS challenges occur below ~1 kHz, where the ripple attenuation due to the vacuum chamber is insufficient. In the original ESR dipole powering scheme with ~20 families, the dipole PS current ripple specifications were found to be near or beyond the state-of-the-art. A recently adopted scheme with a single ESR main dipole PS relaxes these requirements to ~10 parts per million (ppm) rms, which is achievable. Additionally, the vacuum chambers of non-standard cross-sections required at some dipoles must be modified to match the field penetration time constant to that of the standard vacuum chamber. The paper presents the physics reasoning and simulations behind the latest PS ripple specifications, ranging from 5 to 100 ppm rms, depending on the magnet type.
Paper: MOPS065
DOI: reference for this paper: 10.18429/JACoW-IPAC25-MOPS065
About: Received: 28 May 2025 — Revised: 01 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 06 Jun 2025
MOPS066
A Dipole Scheme for the Electron Storage Ring at the Future Electron-Ion Collider
750
The Electron-Ion Collider, which is currently being designed for construction at Brookhaven National Laboratory, will collide polarized electron beams (5-18 GeV) with polarized hadron beams (41-275 GeV) at luminosities up to 10^34 cm−2 s−1. The electron storage ring will contain about 750 dipoles. These dipoles must fulfill not only complex geometric constraints but also requirements set by spin polarization. 576 dipoles will be located in the arcs and arranged as super-bend triplets, which provide reverse bending at 5 GeV to increase the emittance and damping decrement. The rest will be situated in the interaction region and insertion regions around the ring. Tight orbit tolerances driven by beam-beam effects at the interaction point result in very tight field-ripple requirements. While these could be mitigated by powering all dipoles in series, due to the super-bend configuration the dipoles do not all scale similarly with energy. A novel scheme has been developed using variable-turn coil designs and trim coils to achieve the required fields across the energy range. This contribution presents the unique dipole layout developed for the electron storage ring.
Paper: MOPS066
DOI: reference for this paper: 10.18429/JACoW-IPAC25-MOPS066
About: Received: 28 May 2025 — Revised: 05 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 06 Jun 2025
Beam loss study for Hefei Advanced Light Facility
The Hefei Advanced Light Facility (HALF) which is a green-field diffraction-limited storage ring has a relatively low beam lifetime and very low beam emittance. So it is important to study the beam loss for the HALF storage ring to protect the insertion devices and optimize the radiation shielding. In this paper, a simulation for beam loss from two main mechanisms, beam dump and Touschek scattering, are presented. And the collimation scheme is also briefly introduced.
MOPS069
The Elettra 2.0 project status
754
After 31 years of serving the user community with excellent results, on July 2nd 2025 the removal of the Italian third generation synchrotron light source Elettra (www.elettra.eu) will start to be replaced by Elettra 2.0 a fourth-generation one. The project is in full development and, being a diffraction limited light source, Elettra 2.0 will provide ultra-high brilliance and coherence to the experiments while at the same time the machine is designed to provide very short pulses for time resolved experiments. The project status and its possibilities will be presented and discussed
Paper: MOPS069
DOI: reference for this paper: 10.18429/JACoW-IPAC25-MOPS069
About: Received: 24 Apr 2025 — Revised: 30 May 2025 — Accepted: 30 May 2025 — Issue date: 06 Jun 2025
MOPS074
The Novosibirsk fourth-generation light source SKIF development status
758
SKIF (Russian acronym for Siberian Circular Photon Source) – fourth-generation light source under construction in Novosibirsk. Natural emittance (at zero beam current and absent betatron coupling) of the SKIF is 72 pm at 3 GeV beam energy and 476 m circumference. Only two families of sextupoles provide horizontal and vertical dynamic apertures of 12 mm and 3.5 mm, respectively, and energy acceptance more than 5%. The flexibility of the lattice allows the beta functions to be changed in center of straight sections in a wide range from 0.5 m to 16 m, which opens up additional experimental possibilities for users. The paper presents status of development the SKIF project.
Paper: MOPS074
DOI: reference for this paper: 10.18429/JACoW-IPAC25-MOPS074
About: Received: 01 Jun 2025 — Revised: 02 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 06 Jun 2025
Analysis and compensation of the insertion devices effect in the HALF storage ring
The Hefei Advanced Light Facility (HALF) is a diffraction-limited storage ring light source with a beam energy of 2.2 GeV. There are 13 insertion devices (IDs) will be installed in the storage ring, which have severe impacts on the low-energy beam. Especially for the long-period EPU, the non-linear effect can significantly reduce the dynamic aperture of the storage ring. In this paper, the IDs effects are analyzed in detail with kick-map models for the HALF storage ring. Each ID is compensated using a local quadrupole feedforward method. For some EPUs with significant impacts, additional compensation is provided through the shimming of current strips. The analysis and compensation results will be presented in this paper.
MOPS076
Coupling of codes for modeling high-energy-density conditions in fourth generation light sources
760
As previously described*, high-intensity beams of ultra-bright light sources present new machine protection concerns by creating high-energy-density (HED) conditions in beam-intercepting components. Simulating these HED conditions required us to develop a method for coupling three codes for particle dynamics (elegant), particle-matter interaction (MARS/FLUKA), and hydrodynamics (FLASH). This paper discusses the recent advancements made toward this effort including the use of phase and temperature dependent thermal properties such as thermal conductivity and specific heat, transition from MARS to FLUKA, and improved liquid phase dynamics. For benchmarking purposes we compare simulation results with experimental data collected during the final run of the Advanced Photon Source (APS) ring as well as observations of collimator surface damage following the first user run of the upgraded machine. This methodology is also used to make predictions of collimator damage in future APS-Upgrade (APS-U) runs and to examine locations where synchrotron radiation may lead to HED conditions.
Paper: MOPS076
DOI: reference for this paper: 10.18429/JACoW-IPAC25-MOPS076
About: Received: 30 May 2025 — Revised: 02 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 06 Jun 2025
MOPS079
Operational deployment of high brightness LHC beams in the SPS
764
Following the LHC Injector Upgrade programme (LIU) there has been a gradual ramp-up of the intensity of LHC beams in the CERN Super Proton Synchrotron (SPS). This was initially hampered by vacuum issues in several critical components, such as RF cavities and kicker magnets, requiring extensive scrubbing campaigns to condition these components. This paper reviews the current status of the high brightness LHC beams in the SPS, including commissioning evolution, aspects related to beam stability and beam optimization and the current brightness reach. An assessment of the operational readiness of these beams for the High Luminosity LHC era is also given.
Paper: MOPS079
DOI: reference for this paper: 10.18429/JACoW-IPAC25-MOPS079
About: Received: 26 May 2025 — Revised: 04 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 06 Jun 2025
Design, fabrication, and magnetic measurement of a prototype pulsed septum magnet for the Korea-4GSR project
We have designed three types of septa—thin septum, thick septum, and DC septum—for the Korea-4GSR project, a 4 GeV diffraction-limited storage ring incorporating a 200 MeV LINAC and booster synchrotron. The thin septum is an in-vacuum pulsed septum magnet, the thick septum is an out-vacuum pulsed septum magnet, and the DC septum is an out-vacuum DC magnet. This presentation focuses specifically on the prototype design, fabrication, and measurement of the thick septum. The thick septum is designed with a maximum length of 1.25 m, a peak magnetic field strength of 0.56 T, and a minimum orbit distance of 18.6 mm. For prototyping, the length was reduced to 0.6 m while maintaining the same magnetic field strength and orbit distance, enabling the evaluation of manufacturability and magnetic field measurement techniques. We present the results of the design, fabrication, and magnetic field measurements of the prototype thick septum.
MOPS082
Simulation of the ion profile monitors in the Brookhaven AGS
768
Ion profile monitors (IPMs) provide a non-destructive means of measuring the transverse beam size of a passing ion beam in a particle accelerator. The Alternating Gradient Synchrotron (AGS) at Brookhaven National Lab is equipped with two types of IPMs: ion-collecting and electron-collecting. While ion-collecting IPMs are susceptible to significant distortions in the measured beam size due to the space charge of the passing beam, electron-collecting IPMs are much less affected. However, in the AGS, electron-collecting IPMs can only be operated periodically to preserve sensor lifespan, leaving ion IPMs as the sole source of consistent, real-time beam size feedback during operation. In this work, WarpX simulations of IPM operation are used to characterize the measured beam size as a function of beam parameters and IPM operating conditions. These simulations are then compared against experimental data collected from both ion and electron IPMs in the AGS. The findings aim to refine correction factors, enabling more accurate beam size estimations from ion IPM measurements, ultimately improving beam diagnostics and operational efficiency.
Paper: MOPS082
DOI: reference for this paper: 10.18429/JACoW-IPAC25-MOPS082
About: Received: 28 May 2025 — Revised: 02 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 06 Jun 2025
MOPS083
Tune domain behavior of single magnet lattices
771
Single-sextupole and single-octupole lattices ``exhibit .. all the typical properties of more complicated mappings and dynamical issues'', including horizontal resonances of all orders $N$ with island tunes $Q_I$. In general both island tune response spectra and tune modulation drive spectra have multiple lines. Stable motion in transverse phase space is compromised when a pair of drive and response lines align. This vulnerability is illustrated by realistic examples from the Relativistic Heavy Ion Collider.
Paper: MOPS083
DOI: reference for this paper: 10.18429/JACoW-IPAC25-MOPS083
About: Received: 11 May 2025 — Revised: 31 May 2025 — Accepted: 03 Jun 2025 — Issue date: 06 Jun 2025
Status of the storage ring and magnets of the SILA project
SILA (Synchrotron Laser) is a project of the National Research Center Kurchatov Institute (NRC KI) planned for the period 2022-2033. It is aimed at creating a 4th generation synchrotron radiation source and a free electron laser. The storage ring is divided into 40 periods, the perimeter (SR) is 1103 m, the electron energy is 6 GeV, the horizontal emittance is 70 pm∙rad. The free electron laser is divided into 4 branches, the fourth branch is 2-4 GeV, the first - third 6 GeV. Magnets with high field quality requirements were developed for the project: dipoles on permanent magnets: dipole with longitudinal gradient and small dipole, quadrupoles with medium (50 T/m) and high gradient (90 T/m), combined dipole-quadrupole magnets, sextupoles and octupoles. This report will present the status of magnet production, their characteristics obtained during measurements and calculations of dynamics taking into account the field maps of real magnets.
MOPS089
The Korea-4GSR storage ring lattice design
775
We present the lattice design features and performance evaluation of the Korea-4GSR storage ring. This greenfield ring has a 4 GeV beam energy, an 800 m circumference, and 28 cells. A natural emittance of 62 pm is achieved through the implementation of four longitudinal-gradient bends and six reverse bends within the hybrid multi-bend achromat unit cell. The ring includes two high-beta straights, designed to be nearly transparent to the normal straights. Sextupole and octupole magnet strengths have been optimized to suppress major detuning parameters, enabling the ring to achieve a large dynamic aperture and momentum aperture. Commissioning simulations were performed to investigate the optics correction strategy for each commissioning stage and to estimate the performance of the ring under error conditions.
Paper: MOPS089
DOI: reference for this paper: 10.18429/JACoW-IPAC25-MOPS089
About: Received: 23 May 2025 — Revised: 01 Jun 2025 — Accepted: 04 Jun 2025 — Issue date: 06 Jun 2025
Beam dynamic analysis of an electron microtron using General Particle Tracer
Beam Dynamic Analysis of An Electron Microtron Using General Particle Tracer.
MOPS092
Progress on beam dynamics studies for the ISRS isochronous ring spectrometer
779
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: 06 Jun 2025
Reconstruction of the beamlines of the 1.7 MV tandem accelerator to address the users' demands
The KOMAC (Korea Multi-purpose Accelerator Complex)of the KAERI (Korea Atomic Energy Research Institute) has been operating 1.7 MV and 3 MV Tandem accelerators for many years. Recently, in the fields of cultural heritage research and semiconductor device development, there have been strong demands from users for precise composition analysis and large-area & uniform irradiation of proton beam using a 1.7 MV Tandem accelerator. In order to satisfy the needs of these special and important users, the entire beamlines are being rearranged and beamline characterizations are being performed. The external beam PIXE (Proton-Induced X-ray Emission) beamline is being constructed for precise element composition analysis of cultural heritage samples, and for large-area silicon wafer uniform irradiation, the beamline, which was previously capable of uniform irradiation of proton beams up to 6 inch wafers, will be improved to 8 inches. This presentation focuses on the construction of the external beam PIXE beamline for cultural heritage analysis and the results of element composition analysis experiments on cultural heritage samples.
MOPS095
Plan for the KOMAC proton linac upgrade to 200 MeV
783
A 100-MeV proton linac has been operated for over 10 years at KOMAC and used for proton beam services. We are planning to upgrade the linac energy to 200-MeV. By increasing the linac beam energy, we expect the machine to be capable of serving wider application fields including space radiation tests of semiconductor devices and material tests by using high-energy neutrons generated by bombarding a proton beam to a solid target. For the energy upgrade, we consider the SDTL structure for the 200-MeV section. The structure of SDTL is relatively simple so we may reduce the risk and time of development. In addition, we can avoid complex cryogenic systems by choosing a normal conducting approach. For the beamline, two separate target rooms (one for proton, and the other for proton and neutron irradiation) are under design. Details of the planning activity for the KOMAC linac upgrade will be reported in this presentation.
Paper: MOPS095
DOI: reference for this paper: 10.18429/JACoW-IPAC25-MOPS095
About: Received: 28 May 2025 — Revised: 05 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 06 Jun 2025
A FLASH-RT experimental platform and technology research progress
Compared with conventional radiation therapy, the toxic response of FLASH-RT dose rate is significantly reduced and the irradiation time is significantly shortened, and these advantages make FLASH-RT a hot spot in the current radiotherapy field. This paper investigates the development status of FLASH-RT at home and abroad, summarizes the challenges to achieve its clinicalization, and introduces a high-power linear accelerator converted into a Flash-RT experimental platform, with a brief introduction of its overall layout and the pulse modulator, microwave power source and microwave transmission system, control power cabinet, and circulating water cooling system. On the basis of the existing accelerator, the dosimetry is carried out by the detector, and the results show that the average dose rate reaches 60 Gy/s, which meets the requirement of the FLASH effect on the dose rate, and verifies the feasibility of generating the flash effect by this linear accelerator system.
Design and optimization of water-cooling scheme for a 162.5 MHz three-gap rebuncher cavity
To realize the matching of RFQ and DTL, it is expected to place a three-gap rebuncher cavity with a frequency of 162.5 MHz in the MEBT section. The dynamics design parameters of the cavity have been determined, so this paper mainly focuses on the RF design and multi-physics field analysis of the cavity. Modeled in CST, the normal temperature CH-type structure is selected, in order to increase the Q value and reduce the power consumption of the cavity, the parameters such as the radius of the stems, the outer radius of the drift tube, and the length of the drift tube at both ends can be reasonably optimized. Determine the RF parameters and then carry out multi-physics analysis, the most important of which is how to reasonably arrange the water cooling layout so as to reduce the temperature rise of the cavity, in this paper, the water pipe in the end plates finally adopts the 'L' type distribution. After simulation, the deformation and frequency shift of the cavity are within the acceptable range.
Statistical uncertainty studies on various data analysis methods for Stretched Wire Alignment Technology used for the Scorpius Injector
This paper presents statistical uncertainty studies on data analysis methods employed for the alignment of induction voltage adder (IVA) cell magnets in the Scorpius Injector. The Stretched Wire Alignment Technique (SWAT) was utilized to precisely locate and align the magnetic axis of beamline solenoid magnets. A current pulse with duration of approximately 100 µs was propagated through a stretched wire, generating a traveling wave due to the transverse magnetic force acting on the wire. The resulting transverse displacements in both horizontal and vertical directions were measured as a function of time using laser micrometers. By systematically repositioning the wire relative to the mechanical center of the magnet, the true magnetic axis and its offsets from the mechanical center were determined based on the displacement amplitudes or the magnetic field magnitudes inferred from the wire’s motion. Statistical uncertainty analysis of various data analysis methods was conducted to evaluate the reliability of the estimated magnetic axis offsets. The results provide a robust range of offset estimates, ensuring accurate alignment of the IVA cell magnets within the injector system.
Toward the emission of photoelectrons from high field cryogenic radio frequency guns
The intrinsic emittance obtained from radio-frequency (RF) photoinjectors is notably reduced by increasing the launch field at the cathode. Moreover, cryogenic RF guns offer the possibility of producing stronger fields, due to the higher bulk conductivity, while lowering the mean transverse energy (MTE) of near-threshold photo electrons. Such devices thus constitute an ideal tool for driving low emittance electron applications like ultra fast electron diffraction (UED) and free electron lasers (FELs). The CYBORG beamline at UCLA is a stepping stone facility meant to investigate the production of very low MTE photoelectrons in cryogenic RF guns. In this paper we report about the status of the beamline progress. Indeed, after an initial phase dedicated to the study of dark current emission in the high field cryo-RF gun, the facility is heading toward a second phase aimed at producing high brightness photoelectrons. In particular, we discuss the integration of the existing system with the UV laser and a loadlock for cathode exchange as well as the plan for the diagnostics envisioned for the upgraded version of our beamline.
Optimizations for enhancing performance of emittance exchange-based photoinjector
A recent simulation study demonstrated the potential to achieve high 4D-emittance using an emittance exchange (EEX) beamline integrated within a photoinjector. This EEX beamline enabled to achieve the final normalized longitudinal emittance of 0.44 micron, which corresponds to rms bunch length of 7micron and energy spread of 32keV. These results are noteworthy for a 60-MeV photoinjector comprising a gun, linac, and EEX beamline. However, the transverse emittance of approximately 0.6 micron remains a limitation for many applications. To address this, we have conducted computational studies to improve the performance of EEX photoinjector. We present the progress achieved thus far.
Commissioning a 1.5-m linac and its application in UCLA Mithra Laboratory
A 1.5-m linac is being installed at the hybrid gun’s beamline in UCLA Mithra Laboratory for the advanced accelerator research. A preliminary experiment by using a steering magnet showed the electron beam was accelerated from 4 MeV to greater than 30 MeV. A more precise measurement of the beam energy with a new spectrometer magnet is planned in early 2025 as well as the beam emittance. The electro-optic sampling (EOS) experiment is under design for a coarse single-shot bunch length measurement for tuning the beam, while interferometry of the coherent transition radiation (CTR) from a metal foil is ready for the precision measurement of the length for the compressed bunch. For the application of the beam, the generation of coherent cherenkov radiation (CCR) at sub-THz in a hollow dielectric tube is being prepared. The detailed designs and results will be discussed on the spot.
Design and simulation of an electron gun for electron linacs
The electron gun is a crucial component of various vacuum electronic devices, including electron accelerators and electron microscopes. Prior to fabrication, designing and optimizing its geometry is a critical step to ensure optimal performance. In this study, the design and simulation of an electron gun for a linear electron accelerator are presented. The influence of key parameters on the electron gun's performance is analyzed.
Update on the experiment at the Argonne Wakefield Accelerator to actively control the energy chirp of an electron beam with transverse deflecting cavities
A high electron current is often needed in modern electron accelerators. To achieve this, an energy chirp must be imposed on the bunch so the electrons will compress when they pass through a chicane. This energy chirp is usually imposed by accelerating the beam off-crest from the peak fields of RF cavities, which increases the total length and power requirements of the linear accelerator (linac). A novel concept called the Transverse Deflecting Cavity Based Chirper (TCBC)* can be used to impose an energy chirp onto an electron beam, without the need for off-crest acceleration. The TCBC consists of 3 transverse deflecting cavities (TCAVs), which together impose an energy chirp while cancelling out the transverse deflection. An experiment is being developed to demonstrate this concept at the Argonne Wakefield Accelerator (AWA). To run the experiment at AWA, two new TCAVs are under construction, and will arrive at AWA in June 2025. Next the cavities will be cold tested and setup of the experiment will begin. We anticipate running the experiment in late 2025. Here we report on the progress of the experiment and show results from General Particle Tracer** simulations of the beamline.
Dark current in LCLS-II: source characterization and start-to-end modeling
The RF photoinjector in LCLS-II produces several microamperes of dark current via field emission. While the vast majority of this dark current is collimated before reaching the first cryomodule, a small amount (typically less than 1 nA) is transported all the way to the beam switchyard (BSY) dump. In this contribution, we present the results of a start-to-end model of the transport of the dark current through the LCLS-II accelerator, including loss patterns under common machine tuning configurations and evolution of the dark current’s phase space distribution. Understanding the phase space distribution in the BSY will benefit future experiments on the Linac-to-End Station A (LESA) beamline, including searches for dark matter, by enhancing our ability to tune the LESA optics to properly transport the dark current to the experiment.
MOPS115
A muon beam facility at CERN to demonstrate muon ionisation cooling
786
The International Muon Collider Collaboration (IMCC) has been formed following the 2020 European Strategy for Particle Physics Update, with the goal of studying the feasibility of a muon collider at a centre of mass energy of around 10 TeV. One of the most challenging sections of a muon collider is the initial cooling before acceleration, due to the necessity to apply intense magnetic and electric fields to reduce the 6D emittance of the muon beam by 5 orders of magnitude in a very short time, to cope with the limited lifetime of muons (2.2 μs at rest). The IMCC proposes to build a Demonstrator to prove that all the involved technologies (RF, magnets, absorbers, beam instrumentation) can be built at the required specifications, and integrated in order to limit the length of the cooling sections to an acceptable value. Several options are being considered in different laboratories within the collaboration. This paper describes a possible implementation at CERN, in the existing TT7 tunnel.
Paper: MOPS115
DOI: reference for this paper: 10.18429/JACoW-IPAC25-MOPS115
About: Received: 28 May 2025 — Revised: 04 Jun 2025 — Accepted: 04 Jun 2025 — Issue date: 06 Jun 2025
MOPS116
Optics design status for the muon collider rapid cycling synchrotrons
789
The baseline design for the high-energy complex of a muon collider consists of a chain of pulsed synchrotrons spanning an energy range from 63 GeV to the target collision energy of 5 TeV. This chain incorporates both normal and hybrid synchrotrons, featuring a combination of fixed-field superconducting magnets and pulsed normal-conducting magnets. Initial optics designs for the chain of synchrotrons have been completed, with optimization efforts focused on minimizing the aperture dimensions required for dipoles and quadrupoles. Preliminary tracking studies have also been performed to evaluate emittance preservation throughout the acceleration process.
Paper: MOPS116
DOI: reference for this paper: 10.18429/JACoW-IPAC25-MOPS116
About: Received: 02 Jun 2025 — Revised: 02 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 06 Jun 2025
Dynamic aperture correction for Ring Electron Cooler
The Ring Electron Cooler is one option to provide cooling to the Electron Ion Collider’s 275 GeV proton bunches. Using traditional electron cooling this racetrack shaped storage ring uses one straight section to cool the protons and the other one to enhance the radiation damping of the electrons using 2.4 T wigglers. These sections comprise the majority of the ring and are connected by short arcs. Space for sextupoles and octupoles is made in short straight sections between the wigglers. The strong wigglers and limited space for correction magnets create challenges in finding a suitable dynamic aperture correction. In this paper, we outline the challenges present in rings of this type and present a correction scheme that meets the aperture requirements of the design.
The optical stochastic cooling program at Fermilab
Recently, Optical Stochastic Cooling (OSC) became the first demonstrated method for ultra-high-bandwidth stochastic cooling. The initial experiments at Fermilab’s IOTA ring explored the essential physics of the method and demonstrated cooling, heating and manipulation of beams and single particles. Having been validated in practice, with continued development, OSC carries the potential for dramatic advances in the state-of-the-art performance and flexibility for beam cooling and control. The ongoing program at Fermilab is now focused on the development of an OSC system that includes high-gain optical amplification, which promises a two-order-of-magnitude increase in the strength of the OSC force. Here we review the progress and plans for the amplified OSC program. This includes detailed lattice designs and tracking simulations for the various experimental configurations, designs and status for the various hardware systems, and near-term operational plans and use cases.
Development of a high-gain optical amplifier for optical stochastic cooling
Optical stochastic cooling (OSC) is a recently demonstrated state-of-the-art method for beam cooling and control. The strength and utility of OSC can be greatly extended by the inclusion of a high-gain optical amplifier in the system. The amplifier is necessarily a bespoke system whose design and implementation are highly constrained by the OSC physics and system design. In this report, we discuss the unique considerations and performance requirements for the amplifier, review detailed simulations for the integrated system, and report on the current experimental measurements and status.
Design of an isochronous FFAG from 3 to 150 MeV
This study presents the design of an isochronous FFAG accelerator in the energy range of 3 to 150 MeV. A numerical method for solving the isochronous field is introduced, ensuring constant orbital frequencies across the energy range. The dynamic aperture was evaluated, multi-particle simulations were conducted to assess the impact of space charge effects on beam stability at different beam intensities. Preliminary results demonstrate the feasibility of the design.
Simulation of bent crystal collimators in RCS using G4PyORBIT
Bent crystal collimators (BCC) are a promising technology for halo collimation in high-power synchrotrons. To investigate their performance, a BCC module has been integrated into G4PyORBIT, leveraging Geant4's precise modeling of crystal channeling and PyORBIT's beam dynamics simulation capabilities. This study applies the tool to the rapid cycling synchrotron (RCS) at the China Spallation Neutron Source (CSNS). Preliminary results demonstrate the module's ability to simulate beam halo interaction with crystal collimators, evaluate collimation efficiency, and predict beam loss reduction.
MOPS126
Current status of conceptual horizontal splitter design for FFA@CEBAF energy Upgrade
793
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: 06 Jun 2025
Status and perspectives of multi-terawatt long-wave infrared lasers for particle acceleration research
Recent years have seen growing interest within the laser particle acceleration community in laser sources operating at wavelengths substantially longer than the ~1 µm typical of present-day facilities. This renewed focus is fueled by recent advancements in powerful mid- and long-wave infrared (M/LWIR) laser sources. While fundamental advantages, such as the λ2-scaling of ponderomotive potential and the 1/λ2-scaling of critical plasma density, have long been recognized, the emergence of improved laser technologies has made their practical exploitation more accessible and compelling. The backbone of a 5-TW 9.2-µm laser system at BNL ATF is a series of high-pressure CO2 amplifiers, where we have pioneered several novel techniques. These include the use of mixed-isotope active media, a solid-state frequency-conversion-based seed source, and the implementation of chirped-pulse amplification in a gas laser system for the first time. A recent breakthrough in this effort is the development of a reliable bulk-material post-compression scheme, which is now being prepared for full-scale deployment. We report on the current status of our work and discuss the prospects for this field.
MOPS128
User research at Brookhaven Accelerator Facilities Division
797
Brookhaven's Accelerator Facilities Division provides users with access to cutting-edge research tools, including the Accelerator Test Facility (ATF) and the Ultrafast Electron Diffraction (UED) facility. The ATF features an RF photocathode electron LINAC, a femtosecond Ti:Sa laser, and a high-peak-power LWIR laser, all capable of synchronized or independent operation. These tools enable advancements in beam manipulation, accelerator and laser technologies, and the study of low-plasma-density regimes for precise electron seeding into plasma cavities. This supports the development of low-emittance beams for compact laser wakefield accelerators (LWFAs), with applications in science and industry. The UED facility, equipped with an RF electron gun and Ti:Sa laser, facilitates dynamic studies of material structures and other low-energy electron beam research. Starting in 2025, access to these facilities will be available through the BeamNetUS program for academia, industry, and national labs. These unique research opportunities will be presented.
Paper: MOPS128
DOI: reference for this paper: 10.18429/JACoW-IPAC25-MOPS128
About: Received: 30 May 2025 — Revised: 02 Jun 2025 — Accepted: 04 Jun 2025 — Issue date: 06 Jun 2025
MOPS135
Dynamic aperture studies for the EIC electron storage ring
800
The electron-ion collider (EIC), under design at Brookhaven National Laboratory, will consist of two storage rings for collisions of polarized electron and hadron beams. Dynamic aperture (DA) of 10 sigma is required in the electron storage ring (ESR) for the design beam energies from 5 GeV to 18 GeV to ensure an adequate beam lifetime. The DA is limited by chromatic and error effects in a strong optics with a low-beta interaction region. We present results of dynamic aperture studies for the latest ESR lattice (v6.3), which include compensation of non-linear chromaticity, the impact of field imperfections in dipoles, and the effects of dipole orbit.
Paper: MOPS135
DOI: reference for this paper: 10.18429/JACoW-IPAC25-MOPS135
About: Received: 29 May 2025 — Revised: 01 Jun 2025 — Accepted: 04 Jun 2025 — Issue date: 06 Jun 2025
Design update on the EIC electron storage ring
The Electron-Ion Collider (EIC) aims at a luminosity of 10^34 cm^-2 sec^-1. Its Electron Storage Ring (ESR), which will be installed in the existing RHIC tunnel, will store electron beams from 5 to 18 GeV with beam currents up to 2.5 A. The design of the ESR has matured substantially. We will report the design status, including beam dynamics and polarization aspects, value engineering attempts, and latest developments of the injection scheme driven by changes in the injector chain.
MOPS137
EIC 197 MHz crab cavity HOM damping and tolerance analysis
804
Crab cavities, operating at 197 MHz and 394 MHz respectively, will be used to compensate the loss of luminosity due to a 25 mrad crossing angle at the interaction point in the Electron Ion Collider (EIC). Both cavities are of the RF Dipole (RFD) type. To meet the stringent impedance requirements for beam stability and quality, the cavity design must incorporate strong Higher Order Mode (HOM) damping. A special type of HOM coupler has been developed (for both horizontal and vertical HOMs), which consisting of a waveguide stub that couples to the cavity and a waveguide-to-coaxial transition that extracts the HOM power to an external load. This design effectively damps HOMs up to a frequency of 2 GHz. Due to the wide range of frequencies that need to be damped, the damping of some of the HOMs may be sensitive to errors in the cavity and coupler geometry. Therefore, the tolerance of HOM damping with respect to cavity errors needs to be properly addressed in the mechanical design and fabrication process. In this paper, we will present the design of the HOM couplers and the damping tolerance analysis of the 197 MHz cavity.
Paper: MOPS137
DOI: reference for this paper: 10.18429/JACoW-IPAC25-MOPS137
About: Received: 03 Jun 2025 — Revised: 04 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 06 Jun 2025
MOPS138
Simulation of machine-induced background to ALICE in the 2023 LHC ion run
808
During the 2023 ion run at the LHC, where crystal collimation was regularly adopted for the first time, strong background levels were observed at the Inner Tracking System (ITS) of the ALICE detector. Some of the readout chips became saturated, causing losses of angular acceptance. This background was mitigated using a dispersion knob in the beam optics, letting some residual background remain. Considering that the next upgrade of the ALICE ITS foresees a further reduction of the interaction chamber aperture, understanding the mechanisms leading to this background appears critical to envision appropriated mitigation solutions. Preliminary studies showed that this background was related to losses at the upstream tertiary collimator (TCT), impacted by 207Pb82+ ions issued from beam interaction with the crystals of the primary collimation stage. Based on FLUKA simulations, this paper investigates the propagation of the tertiary collimator showers towards the ALICE cavern.
Paper: MOPS138
DOI: reference for this paper: 10.18429/JACoW-IPAC25-MOPS138
About: Received: 27 May 2025 — Revised: 04 Jun 2025 — Accepted: 04 Jun 2025 — Issue date: 06 Jun 2025
MOPS139
Status of VEPP-5 injection complex
812
The VEPP-5 injection complex was put into operation as a source of electronic and positron beams for the VEPP-2000 and VEPP-4M colliders at the end of 2016. To date, an operating energy of 430 MeV and a positron accumulation rate of 3.5 nC/s have been achieved. Options for improving the complex for working with promising installations are being considered. The latest results and prospects of operation are presented.
Paper: MOPS139
DOI: reference for this paper: 10.18429/JACoW-IPAC25-MOPS139
About: Received: 28 May 2025 — Revised: 05 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 06 Jun 2025
MOPS140
Conceptual study of multi-turn injection for SIS100 as a long-term perspective
815
The SIS100 synchrotron, currently under construction as part of the FAIR project, is set to play a pivotal role in advancing high-intensity ion beam research. Reaching the FAIR design intensities for low charge-state heavy ions, e.g. the reference ion U28+ will, however, be challenging due to limitations of the existing SIS18 synchrotron serving as injector to SIS100. In the long-term, the integration of a new linear accelerator capable of delivering high-intensity ion beams at energies up to 200 MeV/u would open the possibility of direct multi-turn injection (MTI) into SIS100, bypassing the SIS18. This paper investigates the MTI process for U28+ beams, aiming to accumulate up to 5x1E11 particles per cycle with high efficiency and minimal particle losses on the electrostatic septum. We present a theoretical analysis of horizontal-plane MTI, outline achievable beam performance, and discuss system requirements. Additionally, the proposed layout and parameters of the MTI equipment are detailed.
Paper: MOPS140
DOI: reference for this paper: 10.18429/JACoW-IPAC25-MOPS140
About: Received: 23 May 2025 — Revised: 05 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 06 Jun 2025
MOPS141
Enhancing beam intensity in SIS18 by a two-plane multi-turn injection approach
819
The existing synchrotron SIS18 will serve as an injector for the FAIR (Facility for Antiproton and Ion Research) complex in booster mode operation. FAIR requires high-intensity beams, placing stringent demands on increasing beam currents in SIS18. Operational experience has shown that significantly increasing beam intensity in SIS18 necessitates both a higher current from UNILAC and improved injection efficiency into SIS18. Currently, injection into the SIS18 synchrotron is performed using conventional multi-turn injection (MTI) in the horizontal plane. To significantly enhance beam intensity in SIS18, we propose implementing a two-plane multi-turn injection scheme. This method aims to boost beam intensity to the desired levels (e.g., uranium beams exceeding 1x1E11 per cycle), even within the current capabilities of UNILAC. This paper discusses how MTI gain can be increased with high efficiency through a two-dimensional technique of painting Lissajous-like patterns in horizontal-vertical space using an inclined electrostatic septum. Simulation examples are presented, illustrating the characteristics of the beam created in SIS18 and the potential effects of space charge forces.
Paper: MOPS141
DOI: reference for this paper: 10.18429/JACoW-IPAC25-MOPS141
About: Received: 25 May 2025 — Revised: 05 Jun 2025 — Accepted: 05 Jun 2025 — Issue date: 06 Jun 2025
Design of the beam transport lines for Super Tau-Charm Facility
The Super Tau-Charm Facility (STCF) is an electron-position collider proposed in China. The injector of STCF provides high quality electron and position beams at an energy up to 2.5 GeV at a repetition rate of 30 Hz. The beam transport system is composed of the electron bypass transport line, the transport lines from positron Linac to Damping Ring and from Damping Ring to positron Linac, and the injection lines from Linac to the collider ring. The low emittance preservation for both beams as well as the complex composition raise challenges for beam dynamics. The design and simulation of the beam transport system is presented in this report.
MOPS143
Feasibility studies for a new transfer line to a muon cooling demonstrator at CERN
823
In the context of ongoing research for a future muon collider, one of the primary challenges is the efficient production and cooling of muons. To address this, a proposal is being explored to construct a demonstrator at CERN for testing a cooling cell. This demonstrator would include a target and focusing system, a chicane around a dump, and a cooling channel. A potential site for this facility is the end of the existing TT7 tunnel, which was used as a neutrino facility in the early 1980s and is presently used for storage of radioactive waste. This paper outlines the initial design studies for the transfer line that will deliver 14 GeV protons from the Proton Synchrotron to the target. The design aims to minimize costs while meeting all geometric and optical requirements. The possibility of operating the line up to 20 GeV is also explored.
Paper: MOPS143
DOI: reference for this paper: 10.18429/JACoW-IPAC25-MOPS143
About: Received: 26 May 2025 — Revised: 02 Jun 2025 — Accepted: 03 Jun 2025 — Issue date: 06 Jun 2025
Design and magnetic field measurement of type c nonlinear magnet
By designing a C-type nonlinear magnet, low emittance beam injection is realized on HALF.
Longitudinal impedance of septum for Hefei Advanced Light Facility
The Hefei Advanced Light Facility (HALF) is a vacuum ultraviolet (VUV) and X-ray diffraction-limited storage ring light source. It has a relatively large dynamic aperture, and an injection scheme with a nonlinear kicker (NLK) was considered for the HALF. This kind of magnet was designed with a small gap shield in the central area to gain a flat magnetic field. A complete prototype has also been produced and the measurement of magnetic field was done. In this paper, an improved structure of the nonlinear kicker is presented based on the previous one. Simulation of the longitudinal impedance has also been done and will be given later.