operation
MOYB2
Novel undulators: the long and winding road to brightness
1
Storage rings and free electron lasers use undulators to produce high-brilliant X-ray photon beams. In order to increase brilliance and photon energy tunability it is necessary to enhance the undulator magnetic peak field on axis by reducing its period without decreasing the electron beam stay clear. Undulator technologies aiming to reach this goal are presented.
Paper: MOYB2
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOYB2
About: Received: 14 May 2024 — Revised: 23 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
MOCD2
Multi-mode cavity design and characterization
18
We present the design and initial characterization of a multi-mode cavity, a novel electromagnetic structure with potential benefits such as compactness, efficiency, and cost reduction. The 2nd Harmonic mode was chosen to linearize the fundamental mode for use as an accelerating and bunching cavity. The reduction in the number of cavities required to bunch and accelerate promises cost and space savings over conventional approaches. Superfish and COMSOL simulations were used to optimize the cavity's geometry with the goal of balancing various design parameters, such as quality factor (Q-factor), harmonic modes, and mode coupling. A 3D-printed copper-plated cavity was used to validate code predictions. The cavity's multi-mode nature positions it for use with other harmonic modes with small deviations in design. For example, a 3rd Harmonic can be used to decrease energy spread by widening the peak of the fundamental. This research lays the foundation for further exploration of the cavity's applications and optimization for specific use cases, with potential implications for a wide range of accelerator fields.
Paper: MOCD2
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOCD2
About: Received: 15 May 2024 — Revised: 22 May 2024 — Accepted: 22 May 2024 — Issue date: 01 Jul 2024
MOPC03
Crossing angle implementation for luminosity maximization in a narrow vertex region in RHIC operation
36
The Relativistic Heavy Ion Collider (RHIC) was designed for head-on collisions in the Interaction Regions. However, RHIC operation in recent years necessitated crossing angles to limit collisions to a narrow longitudinal vertex region, which created operating conditions with a large Piwinski angle (LPA). The angles were implemented by adjusting the shunt currents of four dipoles, the D0 and DX magnets, near the IP. The longitudinal bunch profile often deviates from Gaussian due to the utilization of high-order RF cavities, adding complexity to calculating luminosity reduction with crossing angle. This paper introduces two methods for implementing crossing angles, discusses resultant aperture concerns, conducts numerical calculations of luminosity reduction, and compares these findings with experimental observations.
Paper: MOPC03
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPC03
About: Received: 15 May 2024 — Revised: 21 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
MOPC07
RHIC Au-Au operation at 100 GeV in Run 23
48
The Relativistic Heavy Ion Collider (RHIC) Run 23 program consisted of collisions of 100 GeV gold beams at two collision points for the first time since 2016; the sPHENIX collaboration used the beam to commission their new detector systems while STAR took physics data. Completion of sPHENIX construction pushed the start of the run to May, forcing the collider complex to operate over the summer months and incurring lower than normal availability due to heat and power dip related problems. Issues with dynamic pressure rise during acceleration through transition resulted in a slower ramp up of intensity compared to prior years. Finally, a failure of a warm-to-cold current lead interface in the valve box for the Main Magnet power supply forced the run to end. This paper will discuss the progress made by each experiment and the failure mode, repair and mitigation efforts in preparation for Run 24.
Paper: MOPC07
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPC07
About: Received: 15 May 2024 — Revised: 23 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
MOPC10
Dust-induced beam losses in the Large Hadron Collider
59
Since the start of the Large Hadron Collider (LHC), dust-induced beam loss events resulted in more than hundred premature beam aborts and more than ten dipole quenches during proton physics operation. The events are presumably caused by micrometer-sized dust grains, which are attracted by the proton beams and consequently give rise to beam losses due to inelastic proton-nucleus collisions. Besides the events which trigger dumps or quenches, a large number of smaller dust events has been detected by the beam loss monitors every year. Although these events are not detrimental for physics operation, they are still carefully scrutinized as they give a better understanding about the correlation with beam parameters, about the long-term evolution of event rates, and about possible correlations with shutdown activities and the installation of new equipment. In this contribution, we present a summary of observations from the first three runs of the LHC.
Paper: MOPC10
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPC10
About: Received: 14 May 2024 — Revised: 24 May 2024 — Accepted: 24 May 2024 — Issue date: 01 Jul 2024
MOPC11
Correlating start-of-ramp losses with beam observables at blat-bottom in the LHC
63
Power limitations are expected at injection energy for the main Radio Frequency (RF) system due to the doubled bunch intensity in the High Luminosity (HL-) Large Hadron Collider (LHC) era. One way to overcome these power limitations is to reduce the capture voltage. The smaller RF bucket, however, leads to increased beam losses at the start of the ramp. In practice, these beam losses, which contain both capture and flat-bottom losses, can trigger beam dumps if any of the Beam Loss Monitor (BLM) thresholds are reached. In this contribution, the correlation between start-of-ramp beam loss and beam observables before the ramp is investigated by analysing Beam Current Transformer (BCT) measurements from physics fills. Estimates of how the maximum ratio to BLM dump threshold scales with longitudinal losses are also made. The aim is to make predictions for operation at higher bunch intensities on the basis of these correlations in view of the intensity ramp up for the HL-LHC era.
Paper: MOPC11
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPC11
About: Received: 14 May 2024 — Revised: 19 May 2024 — Accepted: 19 May 2024 — Issue date: 01 Jul 2024
MOPC12
LHC optics commissioning in 2023 and 2024
67
The LHC machine configuration was changed in 2023 compared to previous years, requiring a new set of optics configurations to be measured and corrected. A telescopic optics was deployed in energy the ramp for the first time, which gave rise to a beta-beating of up to 25%. This was corrected using a global correction approach which reduced the beta-beat down to 10%. A change in the phase advance at injection was also applied to mitigate the negative effect of the main octupoles used to stabilize the beam. These measurements and corrections, coupled with the results from the 2024 commissioning, will be presented in this paper
Paper: MOPC12
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPC12
About: Received: 10 May 2024 — Revised: 23 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
MOPC17
Operation of the LHC during the 2023 proton run
87
In 2023 the LHC restarted after the yearly winter shutdown with a new machine configuration optimized for intensities of up to 1.8e+11 protons per bunch. In the first two months of the 2023 run the bunch intensities were pushed up to 1.6e+11 protons per bunch until a severe vacuum degradation, caused by a damaged RF bridge, occurred close to the ATLAS experiment. Following repair, the decision was taken to stop the intensity increase. After a period of smooth operation, a leak developed between the cold mass and insulation vacuum of a low-beta quadrupole, leading to an abrupt stop of the LHC. Thanks to a rapid intervention, the leak could be repaired without warning up large parts of the machine, and the LHC was ready for beam again early September. Special runs at very large beta* were completed in the remaining time before switching to Lead ion operation. The performance achievements and limitations as well as the issues that were encountered over the year will be discussed in this paper.
Paper: MOPC17
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPC17
About: Received: 12 May 2024 — Revised: 23 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
MOPC19
Numerical methods for emittance computation from luminosity
95
The beam transverse emittances play a critical role in high-energy colliders. Various measurement techniques are employed to measure them. In particular, the so-called luminosity emittance scans (or Van der Meer scans) are used in order to evaluate the convoluted beam emittances. This method assumes different emittances in the two planes but identical emittances in the two beams. In this paper, we propose an approach to remove this constraint. After having presented the new measurement protocol, we will discuss its potential and limits, including the statistical measurement error of the luminosity value as obtained from numerical studies.
Paper: MOPC19
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPC19
About: Received: 15 May 2024 — Revised: 17 May 2024 — Accepted: 17 May 2024 — Issue date: 01 Jul 2024
MOPC20
LHC 2023 ion optics commissioning
99
In 2023, about 2 months of the LHC operation were devoted to the Heavy Ions physics, after more than 5 years since the last ion run. In this paper, the results of the 2023 Ion optics commissioning are reported. Local corrections in Interaction Point (IP) 1 and 5 were reused from the regular proton commissioning, but the optics measurement showed the need for new local corrections in IP2. We observed that an energy trim of the level of 10e-4 helped to reduce the optics errors at top energy. The dedicated measurements during the energy ramp revealed a larger than expected beta-beat, which is consistent with an energy mismatch. Furthermore, global corrections were performed to reach a β-beating of about 5% for the collision optics.
Paper: MOPC20
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPC20
About: Received: 13 May 2024 — Revised: 22 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
MOPC21
Feasibility study of the Alice fixed-target experiment with HL-LHC lead ion beams based on crystal-assisted beam Halo splitting
103
The Large Hadron Collider (LHC) at the European Organization for Nuclear Research (CERN) is the world's largest and most powerful particle accelerator, colliding beams of protons and lead ions at energies up to 7 ZTeV. ALICE is one of the detector experiments optimized for heavy-ion collisions. A fixed-target experiment in ALICE is considered to collide a portion of the beam halo, split using a bent crystal, with an internal target placed a few meters upstream of the detector. For proton beams, we have already demonstrated that such a setup provides satisfactory performance in terms of particle flux on target and that it can be safely operated in parallel to regular beam-beam collisions. On the other hand, in the case of lead ion beams, a beam halo is populated with nuclei of many species that may differ in charge, mass and magnetic rigidity, making such a scenario more challenging to operate. This paper summarizes our first considerations of the feasibility of a fixed-target layout at ALICE to be operated with lead ion beams in the LHC.
Paper: MOPC21
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPC21
About: Received: 15 May 2024 — Revised: 20 May 2024 — Accepted: 20 May 2024 — Issue date: 01 Jul 2024
MOPC25
Enhancing beam intensity in RHIC EBIS beamline via GPTune machine learning-driven optimization
118
The utilization of machine learning techniques in accelerator research has yielded remarkable advancements in optimization strategies. This paper presents a pioneering study employing a machine learning algorithm, GPTune, to optimize beam intensity by adjusting parameters within the EBIS injection and extraction beam lines. Demonstrating significant enhancements, our research showcases a remarkable 22% and 70% improvements in beam intensity at two different measurement locations.
Paper: MOPC25
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPC25
About: Received: 08 May 2024 — Revised: 21 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
MOPC35
Design and test of a S band TW buncher for the injector linac of HEPS
140
The bunching system of injector Linac in High Energy Photon Source (HEPS) includes two sub-harmonic bunchers, a pre-buncher and a traveling wave S band buncher. The buncher is a 6-cell constant impedance traveling wave structure operating in 2π/3 mode at 2998.8 MHz. In this paper, the design and test of the traveling wave buncher are presented. First, the characteristic parameters are optimized in CST. Then the buncher is precisely tuned and cold tested with a vector network analyzer after fabrication. Finally, the high power test was finished before installation in Linac. The buncher can operate stably with input power of 10 MW after a week of conditioning. So far the buncher has been applied successfully in Linac of HEPS.
Paper: MOPC35
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPC35
About: Received: 15 May 2024 — Revised: 17 May 2024 — Accepted: 18 May 2024 — Issue date: 01 Jul 2024
MOPC37
Mechanical analysis and design for the LCLS-II-HE soft X-Ray undulator reconfiguration
142
As a part of the High Energy upgrade to the Linac Coherent Light Source II at SLAC, LBNL is responsible for the update of the undulators of the Soft X-Ray (SXR) line. In order to span the required photon energy range, the SXR undulators require longer magnetic period. This increased magnetic period leads to higher magnetic force, requiring updates to certain elements of the design. In contrast, many elements can safely remain unchanged. This presentation details the updates and analyses performed to support the adaptation to HE-SXR, as well as pre-production undulator results.
Paper: MOPC37
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPC37
About: Received: 15 May 2024 — Revised: 24 May 2024 — Accepted: 24 May 2024 — Issue date: 01 Jul 2024
MOPC55
Commissioning results of third C75 cryomodule for CEBAF
188
The program to upgrade CEBAF cryomodules has been implemented to enhance the energy gain of refurbished cryomodules up to 75 MeV. This strategy involves reusing the waveguide end-groups from original CEBAF cavities produced in the 1990s, and existing five elliptical cell cavities are replaced with a new optimized cell shape cavity constructed from large-grain, ingot Nb material. Following fabrication, each cavity undergoes centrifugal barrel polishing and electropolishing and then is tested at 2.07 K. Eight cavities are then assembled into "cavity pairs" and tested at 2.07 K before integration into the cryomodule. This paper presents the outcomes of the cavity qualification for the third C75 module, providing a detailed account of the assessment in both a vertical cryostat and the commissioning results of the cryomodule. Furthermore, efforts have been made to address performance limitations arising from field emission and multipacting.
Paper: MOPC55
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPC55
About: Received: 14 May 2024 — Revised: 19 May 2024 — Accepted: 19 May 2024 — Issue date: 01 Jul 2024
MOPC63
New high power linear accelerator ABC and platform
208
At Varex Imaging Corporation, we have started a transition to our in-house supply of Accelerator Beam Centerlines (ABC), replacing Varian as a supplier. As part of this program we are considering changing design of our K-15, the only standard production unit capable of delivering Bremsstrahlung at 12000 R/min@1m by striking a copper target with high energy electron beam at 15 MeV. We plan on changing the RF source from frequency of 2856 MHz, used by Varian to 2998 MHz, establishing one common frequency for all our S-Band linear accelerator supply. We may be using a two-section design of the new 15 MeV ABC and yet various designs are being investigated, including, but not limited to two collinear standing wave (SW) sections and a patented combination of SW and Traveling Wave (TW) Sections with reverse feed. We have analyzed both concepts and present the preliminary analysis results. The platform can be used for running guides at various energy levels from 2 to 20 MeV, continuously changing energy or doing that selectively, various combinations of energy levels will be possible, also, upgrading the platform to higher average beam power levels. Indeed, operating at high average beam power above 1-2 kW level may require new advanced target development, and in case of e-beam applications, a scan horn will be required for extracting e-beam from vacuum to air.
Paper: MOPC63
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPC63
About: Received: 07 May 2024 — Revised: 17 May 2024 — Accepted: 17 May 2024 — Issue date: 01 Jul 2024
MOPG04
Challenges and mitigation measures for synchrotron radiation on the FCC-ee arcs
292
In a high-energy circular electron-positron collider like the Future Circular Collider (FCC-ee) at CERN, synchrotron radiation (SR) presents a significant challenge due to the radiation load on collider magnets and equipment in the tunnel like cables, optical fibers, and electronics. The efficiency of the anticipated photon absorbers in the vacuum chambers depends on the operational beam energy, ranging from 45.6 GeV to 182.5 GeV. Radiation load studies using FLUKA are conducted for the four operation modes to assess the SR impact on various systems and equipment. Particularly at higher energies (120 GeV and 182.5 GeV), the radiation levels in the tunnel environment would likely not be sustainable. The objective is to implement a mitigation strategy that enables the placement of essential components, such as electronics, power converters, and beam instrumentation, in the tunnel, while enduring both instantaneous and long-term radiation effects over multiple years.
Paper: MOPG04
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPG04
About: Received: 07 May 2024 — Revised: 17 May 2024 — Accepted: 17 May 2024 — Issue date: 01 Jul 2024
MOPG05
Low-alpha operation of the IOTA storage ring
296
Operation with ultra-low momentum-compaction factor (alpha) is a desirable capability for many storage rings and synchrotron radiation sources. For example, low-alpha lattices are commonly used to produce picosecond bunches for the generation of coherent THz radiation and are the basis of a number of conceptual designs for EUV generation via steady-state microbunching (SSMB). Achieving ultra-low alpha requires not only a high-level of stability in the linear optics but also flexible control of higher-order compaction terms. Operation with lower momentum-compaction lattices has recently been investigated at the IOTA storage ring at Fermilab. Experimental results from some initial feasibility studies will be discussed in the context of ensuring an improved understanding of the IOTA optics for future research programs.
Paper: MOPG05
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPG05
About: Received: 24 May 2024 — Revised: 28 May 2024 — Accepted: 28 May 2024 — Issue date: 01 Jul 2024
MOPG07
Dispersion orbit detection by orbit harmonic analysis and potential applications
304
Electron storage rings in synchrotron light sources are typically composed of 𝑁 identical sectors that repeat over the ring. Transverse plane betatron frequencies are not an integer harmonic of the beam revolution frequency to avoid that accelerator imperfection effects are turn-by-turn amplified causing beam losses. Consequently, orbit variations induced by ring parameters not affecting beam energy, do not show periodicity equal to 𝑁, while variations affecting energy do generate dispersion orbits with 𝑁 periodicity. In the relativistic case, the beam energy in a ring is set by its closed orbit length (defined by the RF frequency) jointly with the field in bend magnets. Ring thermal expansion/compression causes energy variations and periodic dispersion orbits. In the frequency domain, the real-time amplitude of these orbits can be determined from their 𝑁 spectral line magnitude and phase. This info can be used in orbit feedbacks to adjust the RF to remove orbit dispersion components avoiding conflict with the corrector magnet action. Initial measurements performed at the Advanced Light Source in Berkeley to validate the technique are presented. Additional application possibilities are also discussed.
Paper: MOPG07
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPG07
About: Received: 14 May 2024 — Revised: 20 May 2024 — Accepted: 20 May 2024 — Issue date: 01 Jul 2024
MOPG16
FLASH status – FEL user facility between two upgrade shutdowns
335
FLASH, the XUV and soft X-ray free-electron laser user facility at DESY, is in the transitional period between two substantial upgrade shutdowns within the FLASH2020+ upgrade project. FLASH consists of a common part FLASH0 (injector & superconducting linac), two FEL beamlines (FLASH1/2) and an experimental beamline FLASH3, accommodating the plasma wakefield experiment FLASHForward. The first (2021/22) shutdown was aimed at upgrading FLASH0 and install an APPLE-III undulator in the otherwise unchanged beamline FLASH2, enhancing the third harmonic at flexible output polarization. The next (2024/25) shutdown will focus on the complete exchange of the FLASH1 beamline to allow for externally seeded operation in the range from 60 nm down to 4 nm at 1 MHz bunch repetition rate (600 μs trains at 10 Hz train repetition rate). We report on the operation between the two shutdowns which was, to a large extend, dedicated to FEL operation for users and on the commissioning of the new features implemented in the last shutdown.
Paper: MOPG16
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPG16
About: Received: 15 May 2024 — Revised: 18 May 2024 — Accepted: 19 May 2024 — Issue date: 01 Jul 2024
MOPG18
Integrating sustainable computational strategies in light source accelerator upgrades
343
The operation of light source accelerators is a complex process that involves a combination of empirical and theoretical physics, simulations, and data-intensive methodologies. For example, the FLASH1 beamline at DESY is upgrading to an external seeding FEL light source*. We utilize special diagnostics, machine learning algorithms, and comprehensive simulations to achieve this. To optimize resources, we constantly look to improve our approach, allowing us to robustly control the accelerator and meet the desired stability of our users. Machine learning and GPU-based algorithms have become crucial, enabling us to employ advanced optimization techniques and possibly AI. However, in many cases, it is imperative to establish a robust mechanism for simulations involving large particle numbers to ensure that future upgrades and experiments can effectively and sustainably leverage these computational strategies.
Paper: MOPG18
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPG18
About: Received: 20 May 2024 — Revised: 27 May 2024 — Accepted: 27 May 2024 — Issue date: 01 Jul 2024
MOPG20
VUV diagnostics for oscillator FEL operation from 200 nm to 155 nm
347
Powered by a storage ring with energies ranging from 240 MeV to 1.2 GeV, the Duke Free-Electron Laser (FEL) has demonstrated operation across a broad wavelength spectrum from infrared (IR) to vacuum ultraviolet (VUV): 1100 nm to 170 nm. This FEL serves as a photon source for the High Intensity Gamma-ray Source (HIGS), producing polarized, near-monochromatic, and high-flux Compton gamma-ray beams in an extensive energy range from 1 MeV to 120 MeV, with the highest flux recorded at 3.5e+10 ph/s (total) around 10 MeV. To generate high-energy gamma-ray beams above 80 MeV, the FEL must operate in the VUV region from 195 nm to 155 nm. This work describes the development and operation of VUV beam diagnostics within a nitrogen-purged enclosure, with increased difficulty as the wavelength shortens towards 155 nm. We will discuss the challenges encountered and the solutions found for VUV beam diagnostics, leading to the successful FEL lasing in the VUV region.
Paper: MOPG20
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPG20
About: Received: 15 May 2024 — Revised: 20 May 2024 — Accepted: 20 May 2024 — Issue date: 01 Jul 2024
MOPG23
Characterization of FEL mirrors with long ROCs
350
FEL oscillators typically employ a two-mirror cavity with spherical mirrors. For storage ring FELs, a long, nearly concentric FEL cavity is utilized to achieve a reasonably small Rayleigh range, optimizing the FEL gain. A challenge for the Duke storage ring, with a 53.73 m long cavity, is the characterization of FEL mirrors with a long radius of curvature (ROC). The Duke FEL serves as the laser drive for the High Intensity Gamma-ray Source (HIGS). As we extend the energy coverage of the gamma-ray beam from 1 to 120 MeV, the FEL operation wavelength has expanded from infrared to VUV (1 micron to 170 nm). To optimize Compton gamma-ray production, the optimal value for the mirror's ROC needs to vary from 27.5 m to about 28.5 m. Measuring long mirror ROCs (> 10 m) with tight tolerances remains a challenge. We have developed two different techniques, one based on light diffraction and the other on geometric imaging, to measure the long ROCs. In this work, we present both techniques and compare their strengths and weaknesses when applied to measure mirror substrates with low reflectivity and FEL mirrors with high reflectivity.
Paper: MOPG23
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPG23
About: Received: 16 May 2024 — Revised: 21 May 2024 — Accepted: 22 May 2024 — Issue date: 01 Jul 2024
MOPG24
High level software for operating an EEHG FEL
354
Reliable operation of a seeded Free Electron Laser requires the simultaneous control of several electron-beam, laser and accelerator parameters. With EEHG the complexity increases due to the second seed laser and the strong dependence of EEHG bunching to seeding parameters. With the recent upgrade of the FEL-1 line, FERMI is the first FEL facility to be operated in EEHG mode for users. This required a major work for developing software tools that could be used to easily set the FEL at the desired wavelength. We report here on the recent software developments at FERMI for the operations of the new FEL-1. An important prerequisite for EEHG is to determine both the electron beam energy spread and seed laser induced energy modulation. This is done by using HGHG time dependent bunching equations to match experimental parameters scans. With these data, optimal EEHG settings of the machine parameters are then calculated to reach the desired FEL wavelength. The requested parameters are then sent to interface tools that accurately control laser, undulator, chicane and electron beam.
Paper: MOPG24
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPG24
About: Received: 14 May 2024 — Revised: 21 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
MOPG40
Start-to-end simulation of second hard X-ray beamline at the PAL-XFEL and plans of R&D activities on high-brightness XFEL generation
384
A second hard X-ray beamline (HX2) at the PAL-XFEL (Pohang Accelerator Laboratory, X-ray Free Electron Laser) has been proposed to meet the increased demands of XFEL science. A photon energy ranging between 1.5 to 10 keV was determined to cover low photon energy with enhanced FEL pulse energy of about 3.0 mJ, and to cover mostly used range between 8 to 10 keV simultaneously. Accordingly, baseline design of the electron beamline was completed using MAD-X code. Here, to avoid physical overlap of the beamline elements, a dog-leg transport line is installed. In addition to first-order optics design, complete start-to-end simulation is performed to understand the evolution of the 6D electron beam phase space and to optimize the beam parameters such as energy chirp, energy spread, and emittance at the entrance of the undulator. In this study, we will show the start-to-end simulation by using Impact-T for injector section and ELEGANT for the remaining sections from linac modules to the end of the HX2 undulator line. Particularly, we will discuss whether coherent synchrotron radiation effects along the dog-leg section is suppressed so that the beam phase space distortion is minimized. Plus, we will introduce planned R&D activities such as AI/ML-based injector operation (virtual machine) and various studies on the XFEL modes such as multi-bunch operation, enhanced SASE (ESASE), and THz FEL.
Paper: MOPG40
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPG40
About: Received: 15 May 2024 — Revised: 20 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
MOPG67
Compact high average power THz source driven by thermionic RF gun
412
This work presents the design of a compact high-efficiency terahertz source, a collaborative effort between UCLA and RadiaBeam Technologies. The system, driven by a thermionic RF gun, features prebunching elements including alpha-magnet and electromagnetic chicane to effectively compress the long beam generated from the gun. By sending such beam into tapering enhanced waveguide oscillator, we can achieve high efficiency energy extraction in different regimes. This work focuses on the beam dynamics in the beamline prior injection into the undulator. A brief mention of the simulation results for radiation generation is also presented.
Paper: MOPG67
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPG67
About: Received: 15 May 2024 — Revised: 20 May 2024 — Accepted: 20 May 2024 — Issue date: 01 Jul 2024
MOPR02
A compact electron accelerator for muon production
452
The muon is a unique particle. It is an elementary particle similar to the electron, but with a mass approximately 200 times greater. Because of their high penetrating power, muons can also be used for imaging such as non-destructive inspection and muon tomography for interior surveys of large structures. Muons derived exclusively from cosmic rays have heretofore been used for these applications, but the low rate and restricted angular range of cosmic rays restricts their usefulness.In this article, a compact and portable muon source based on super-conducting electron accelerator technology is considered. The addition of a muon accelerator provides a variable energy, portable muon source.
Paper: MOPR02
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPR02
About: Received: 15 May 2024 — Revised: 23 May 2024 — Accepted: 24 May 2024 — Issue date: 01 Jul 2024
MOPR05
Design of prototype magnet for FETS-FFA
464
Capable of achieving a high repetition rate with strong focusing, Fixed Field Alternating gradient (FFA) accelerators have the potential to be used for pulsed high intensity operations. With no pulsed high intensity FFA ever built so far, a prototype machine called FETS-FFA has been proposed to study the FFA option for the next generation spallation neutron source (ISIS-II). One of the essential components of this machine will be the main magnets which must satisfy the following conditions: zero chromaticity during acceleration, flexibility in operating tune point to test dynamics for high beam intensity and a large dynamic aperture to avoid uncontrolled loss. The chosen lattice design utilizes spiral magnets to provide edge focusing to focus in the vertical direction while also introducing a reverse bending magnet to better control the vertical tune. A three-dimensional study is being carried out in OPERA 3D software to investigate the parameters of the magnets to achieve the required field. The details on the design will be presented in this paper.
Paper: MOPR05
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPR05
About: Received: 15 May 2024 — Revised: 20 May 2024 — Accepted: 20 May 2024 — Issue date: 01 Jul 2024
MOPR13
High-efficiency traveling-wave accelerating structure with ceramic insertion
482
In a radiofrequency accelerating structure with ceramic insertion, high shunt impedance (162 megaohm/m) and high group velocity (3.1% of the speed of light) are achieved simultaneously. The ceramic insertion is in the form of a cylinder, sandwiched between copper endplates with the beam aperture opened at the center. We report our theoretical study on this novel type of traveling wave accelerating structure that operates with a 2pi/3-mode at 5.7 GHz. The high shunt impedance is realized by the low-loss, highly reflective ceramic insertion confining the accelerating mode at the center. The high group velocity, or fast filling time of the radiofrequency wave, is made possible by the side coupling slots designed with large dimensions. As a result, this novel traveling wave accelerating structure enhances the power efficiency significantly, by two means. The high shunt impedance allows providing a greater accelerating gradient with a given amount of radiofrequency power. The fast filling time allows an earlier start of the beam acceleration within each radiofrequency power pulse, thus leading to a higher duty factor of the accelerator beam production. This type of the structure design allows using metallic iris features, which minimizes the electric field magnitude witnessed by the ceramic component. We also discuss the scheme of using periodic permanent magnets to focus an electron beam in the accelerating structure. The unique radiofrequency coupler design is also addressed.
Paper: MOPR13
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPR13
About: Received: 14 May 2024 — Revised: 16 May 2024 — Accepted: 16 May 2024 — Issue date: 01 Jul 2024
MOPR26
Test of a metamaterial structure for structure-based wakefield acceleration
515
Metamaterial accelerators driven by nanosecond-long RF pulses show promise to mitigate RF breakdown. Recent high-power tests at the Argonne Wakefield Accelerator (AWA) with an X-band metamaterial structure have demonstrated to achieve a gradient of 190 MV/m, while we also observed a new acceleration regime, the breakdown-insensitive acceleration regime (BIAR), where the RF breakdown may not interrupt acceleration of a main beam. Statistical analysis between different breakdown types reveals that the characteristics of the BIAR breakdown are beneficial to high-gradient acceleration at short pulse lengths.
Paper: MOPR26
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPR26
About: Received: 15 May 2024 — Revised: 23 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
MOPR32
High gradient operation of cryogenic C-band RF photogun at UCLA
527
Future electron accelerator applications such as x-ray free electron lasers and ultrafast electron diffraction are dependent on significantly increasing beam brightness. We have designed and produced a new CrYogenic Brightness-Optimized Radiofrequency Gun (CYBORG) for use in a new beamline at UCLA to study the brightness improvements achievable in this novel low temperature high gradient accelerating environment. We are currently in the process of commissioning the photogun for operation with peak cathode fields in excess of 120 MV/m. We report here on the status of conditioning the photogun and report on dark current measurements and maximum field achieved thus far.
Paper: MOPR32
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPR32
About: Received: 15 May 2024 — Revised: 24 May 2024 — Accepted: 24 May 2024 — Issue date: 01 Jul 2024
MOPR39
Investigation of plasma stability of the prototype plasma lens for positron matching
538
The quest for novel technologies in the ever-evolving landscape of scientific exploration has led to the investigation of plasma lensing as a potential solution for optical matching devices for all kinds of positron sources. This research becomes increasingly significant as the need for higher data output demands innovative concepts to increase positron yield and therefore luminosity. Instabilities were observed during the first test trials. This poster presents the results of high-temporal resolution imaging to analyse the discharge instabilities. Furthermore, the results show not expected but interesting insights and challenges. Overcoming these challenges is pivotal for a future application of plasma lenses as an integral part of high-performance positron sources.
Paper: MOPR39
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPR39
About: Received: 15 May 2024 — Revised: 11 Jun 2024 — Accepted: 11 Jun 2024 — Issue date: 01 Jul 2024
MOPR70
Development of inductive high temperature oven (HTO) at the facility for Rare Isotope Beams
602
Many of ion beams generated by the Electron Cyclotron Resonance Ion Source (ECRIS) originate from solid-state materials and undergo a conversion process to transition from a solid to a gaseous state before being introduced into the plasma. Established techniques for thermal evaporation encompass ovens and others. The primary objective is to advance oven technology targeting increased reliability, durability, efficiency, and an expanded temperature range. At the Facility for Rare Isotope Beams (FRIB), a specialized inductive High Temperature Oven (HTO) has been developed to ensure the consistent and reliable production of metallic ion beams. ANSYS simulations have been carried out to maximize the temperature inside the oven and to help select the materials used with the oven based on the analysis on the heat distribution. Off-line tests have shown that the oven operates durably at temperatures close to 2000°C, and on-line tests already demonstrated beam intensity as high as 52 eµA of 238U35+ and 60 eµA of 238U33+. This paper presents and discusses the design features, ANSYS simulations, off-line and on-line test results of the HTO.
Paper: MOPR70
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPR70
About: Received: 14 May 2024 — Revised: 17 May 2024 — Accepted: 17 May 2024 — Issue date: 01 Jul 2024
MOPR78
PHOtocathode Epitaxy and Beam Experiments laboratory at Cornell: current status and future work
630
High-efficiency alkali antimonide photocathodes degrade with little oxidation, making them hard to characterize and test outside their growth chamber. In this proceeding, we report on the design and performance of the PHOtocathode Epitaxy and Beam Experiments (PHOEBE) laboratory at Cornell University, where the growth, characterization, and testing of alkali photocathodes in vacuum has been successfully integrated. The growth of photocathodes is characterized in-situ by measuring the QE and by looking at the photocathode’s reflection high energy electron diffraction (RHEED) pattern. Once the desired photocathode is obtained, it is moved to a storage chamber to collect spectral response data, after which it is moved to the cryogenic emittancediagnostic beamline via a vacuum suitcase. A rapid cathode exchange system in the diagnostic beam can efficiently transfer alkali-antimonide photocathodes to beamline operation with little QE loss. Using this beamline, the mean transverse energy of the photocathode can be measured at various photoexcitation wavelengths in the visible spectrum and sample temperatures within 20 - 300 K.
Paper: MOPR78
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPR78
About: Received: 16 May 2024 — Revised: 17 May 2024 — Accepted: 17 May 2024 — Issue date: 01 Jul 2024
MOPR80
Alternative negative electron affinity activation studies at HERACLES
638
A new growth chamber at the High ElectRon Average Current for Lifetime ExperimentS (HERACLES) beamline at Cornell has been installed enabling Negative Electron Affinity (NEA) activations of GaAs using Cs-Sb-O and Cs-Te-O recipes. These activation recipes have been shown to be more robust against vacuum poisoning when measured at low voltages and currents. In this proceeding we present charge lifetime measurements of these recipes when operated in a high voltage, high current electron gun.
Paper: MOPR80
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPR80
About: Received: 16 May 2024 — Revised: 21 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
MOPR81
An overview of spin-polarized photocathode research at Cornell University
642
The development of a robust spin-polarized electron source capable of sustaining mA scale average beam currents in a photoinjector is critical for many future accelerator facilities such as the International Linear Collider (ILC). In this proceeding we overview the several efforts being carried out at Cornell towards this end, including: high current (>1 mA) gun tests of robust activation recipes of GaAs at the HERACLES beamline, the development and demonstration of GaN as a robust spin polarized source and Density Functional Theory (DFT) ab initio studies of alkali-antimonide photocathodes as potential spin polarized electron sources.
Paper: MOPR81
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPR81
About: Received: 20 May 2024 — Revised: 23 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
MOPR82
Chemical robustness enhancement of negative electron affinity photocathodes through cesium-iodide deposition
646
Photocathodes at Negative Electron Affinity (NEA), like GaAs and GaN, allow for efficient production of spin-polarized electrons. When activated to NEA with cesium and an oxidant, they are characterized by an extreme sensitivity to chemical poisoning, resulting in a short operational lifetime. In this work, we demonstrate that deposition of a cesium iodide (CsI) layer can be used to enhance the dark lifetime of both GaN and GaAs photocathodes activated with cesium. The mechanism behind this improvement is investigated using X-ray Photoelectron Spectroscopy (XPS) and Atomic Force Microscopy (AFM) techniques.
Paper: MOPR82
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPR82
About: Received: 17 May 2024 — Revised: 21 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
MOPR83
Design and construction of the photocathode vacuum suitcase for CARIE test facility
650
This poster will discuss the design of the photocathode vacuum suitcase that we currently design and construct for the Cathodes And Radiofrequency Interactions in Extremes (CARIE) test stand. The CARIE test stand is built to test behavior of the high quantum efficiency photocathodes at strong fields. The semiconductor photocathodes must be grown and delivered to the photoinjector under ultra-high-vacuum (UHV) conditions in order to maintain their properties. This is typically done using portable UHV vacuum systems called vacuum suitcases. We will discuss the vacuum and photocathode handling design of the CARIE vacuum suitcase and the status of the suitcase construction and testing.
Paper: MOPR83
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPR83
About: Received: 15 May 2024 — Revised: 17 May 2024 — Accepted: 17 May 2024 — Issue date: 01 Jul 2024
MOPS02
Modeling interference of two first-order resonances with two Siberian snakes using machine learning
682
The model of spin depolarization invoking isolated resonances hinges on a closed-form solution of energy ramping with the Single Resonance Model by Froissart and Stora. However, for non-resonant orbital tunes, resonant depolarization by single resonance crossing is impossible in the SRM while using a pair of Siberian Snakes since the amplitude-dependent spin tune is then fixed to one-half. Polarization loss in RHIC demonstrates that the isolated resonances model is not a good approximation of polarization dynamics with two Siberian Snakes. We therefore extend the model in which a pair of resonances in close proximity push the amplitude-dependent spin tune away from one-half in the presence of Siberian Snakes, allowing the crossing of higher-order spin resonances associated with depolarization. We present results from applying Machine Learning methods that establish spin transport models with two overlapping resonances from tracking data.
Paper: MOPS02
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPS02
About: Received: 15 May 2024 — Revised: 19 May 2024 — Accepted: 19 May 2024 — Issue date: 01 Jul 2024
MOPS06
Simulations and experiments for dynamic aperture studies in the LHC ion operation
698
Dynamic Aperture (DA) studies, based on single-particle tracking simulations including important non-linear fields such as beam-beam effects, have played a crucial role in guiding the operation of the Large Hadron Collider (LHC) in proton-proton collisions. The correspondence between DA computed through simulations and the actual beam lifetime during operation has been established for proton beams through dedicated experiments at the LHC. However, such an approach has not yet been applied to the Pb ion operation of the accelerator, as the simulation tools have not been rigorously benchmarked against experimental data yet. The present paper presents the simulation studies and experimental tests performed to establish the correlation between DA and beam lifetime for ions. The main focus lies on exploring the beam-beam limit when the crossing angle is significantly reduced in all LHC experiments as compared to the nominal configuration. This approach opens the possibility to operate with reduced crossing angles or reduced $\beta^*$ within the beam-beam limit, potentially leading to an enhanced performance of the accelerator with ions.
Paper: MOPS06
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPS06
About: Received: 15 May 2024 — Revised: 21 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
MOPS07
Classification of potentials for self consistent symplectic space charge
702
A general theory of symplectic tracking under the influence of space charge force is not yet available, even if some specific solution was proposed [1, 2]. In this paper we will first review how the pull-back of the Lie transform can be used to self-transport the beam distribution and its associated electromagnetic potential under the effect of the space-charge. We will then classify the functions suitable for an iterative algorithm with the Lie transform. Those functions will be used to describe the electromagnetic potential of the space charge.
Paper: MOPS07
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPS07
About: Received: 14 May 2024 — Revised: 20 May 2024 — Accepted: 20 May 2024 — Issue date: 01 Jul 2024
MOPS10
Koopman operator method for nonlinear dynamics analysis using symplectic neural networks
713
Data driven methods have proved to be a useful tool for analyzing Hamiltonian systems. The symplectic condition is a strong constraint on Hamiltonian systems and it is therefore useful to implement this constraint into neural networks to ensure the accuracy of long term predictions about the system. One such method is the use of SympNets*, linear, activation, and gradient layers that guarantee the symplectic condition is met without the use of symplectic integration or extra gradient calculations. Data driven methods are also useful for calculating Koopman operators which aim to simplify nonlinear dynamical systems into linear ones. By using SympNets, one can ensure that the transformation described by the Koopman operator is symplectic, reversible, and more easily trained.
Paper: MOPS10
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPS10
About: Received: 15 May 2024 — Revised: 23 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
MOPS16
Optimizing the sextupole configuration for simultaneous correction of third order resonances at the recycler ring
736
For the Recycler Ring at Fermilab, space charge tune shifts of almost 0.1 will have to be dealt with under the Proton Improvement Plan (PIP-II) framework. This will lead to the excitation of third order resonances. The minimization of Resonance Driving Terms (RDTs) allows to mitigate the harmful effect of these betatron resonances. Past work has shown that previously-installed sextupoles can compensate the RDTs of individual third order resonance lines, thus reducing particle losses in these operational regimes. Nevertheless, trying to compensate multiple resonances of the same order simultaneously with these existing sextupoles is limited due to current constraints in the magnets. The following study showcases the procedure to install additional sextupoles in order to aid the compensation of multiple resonances. This includes the optimization of the new sextupoles' locations in order to cancel out multiple RDTs while minimizing the currents needed. This is followed by a verification of their effectiveness by means of the RDT response matrix.
Paper: MOPS16
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPS16
About: Received: 16 May 2024 — Revised: 21 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
MOPS17
Resonance compensation at the CERN PS booster aided by Bayesian optimization and BOBYQA
740
The CERN Proton Synchrotron Booster (PSB) operation involves the crossing of multiple resonance lines in the tune diagram. Loss maps from dynamic tune scans are a helpful way to visualize and quantify the strength of such resonances. Sextupole and octupole correctors can be used in order to partially or fully compensate multiple resonance lines, i.e., third and fourth order lines. The following work explores the application of advanced optimization algorithms such as Bayesian Optimization and Bound Optimization By Quadratic Approximation (BOBYQA) in order to compensate these resonance lines with available correctors.
Paper: MOPS17
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPS17
About: Received: 15 May 2024 — Revised: 21 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
MOPS19
Tracking study of the bimodal RF cavity for storage ring light source
748
Beam lengthening is an effective and commonly used method to improving the beamlife of storage rings. Based on the previously proposed design of a room temperature conducting bimodal RF cavity, we conducted relevant dynamic simulations. Tracking study on a simulated storage ring lattice with the beam energy of 2 GeV and the synchronous radiation energy of 357 KeV, the results show that, the bimodal RF cavity which contains an accelerating field and a third harmonic field can effectively lengthen beam length, the beam lengthening effect similar to the double RF system which consists of main RF cavity and third harmonic cavity.
Paper: MOPS19
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPS19
About: Received: 15 May 2024 — Revised: 20 May 2024 — Accepted: 20 May 2024 — Issue date: 01 Jul 2024
MOPS59
Fast-ramping alpha magnet for interleaved operation at ANL APS
856
RadiaBeam is designing and manufacturing a fast-ramping alpha magnet is developed for interleaved operation at the Argonne Advanced Photon Source (APS). This interleaving operation requires the alpha magnet to stably complete a 5 s long cycle with a 100 ms ramp-up, 1000 ms nominal field output and a 100 ms ramp-down. A laminated yoke is used to minimize eddy currents, ensure fast field response times and reduce core-loss during operation. The magnetic and mechanical design demonstrating the performance of this 2.75 T/m maximum field gradient alpha magnet within a 10 cm x 14 cm good field region will be presented along with the current fabrication status.
Paper: MOPS59
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPS59
About: Received: 15 May 2024 — Revised: 28 May 2024 — Accepted: 28 May 2024 — Issue date: 01 Jul 2024
MOPS65
Enhancing CERN-SPS slow extraction efficiency: meta Bayesian optimisation in crystal shadowing
870
The Super Proton Synchrotron at CERN serves the fixed-target experiments of the North Area, providing protons and ions via slow extraction, and employs the crystal shadowing technique to significantly minimize losses. Over the past three operational years, the use of a crystal, positioned upstream of the electrostatic septum to shadow its blade, has allowed to achieve a 25% reduction in losses. Additionally, a novel non-local shadowing technique, utilizing a different crystal location, has successfully halved these losses. While using a single crystal in this location resulted in a temporary 50% reduction in slow extraction losses at nominal intensity, this effect was not sustainable beyond a few hours. This limitation is primarily attributed to the magnetic non-reproducibility and hysteresis inherent to the SPS main dipoles and quadrupoles. In this paper, we introduce the application of the Rank-Weighted Gaussian Process Ensemble to the setup of shadowing. We demonstrate its superior efficiency and effectiveness in comparison to traditional Bayesian optimization and other numerical methods, particularly in managing the complex dynamics of local and non-local shadowing.
Paper: MOPS65
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPS65
About: Received: 08 May 2024 — Revised: 22 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
MOPS68
Automated optimization of accelerator settings at GSI
882
The complexity of the GSI/FAIR accelerator facility demands a high level of automation in order to maximize time for physics experiments. Accelerator laboratories world-wide are exploring a large variety of techniques to achieve this, from classical optimization to reinforcement learning. This paper reports on the first results of using Geoff at GSI for automatic optimization of various beam manipulations. Geoff (Generic Optimization Framework & Frontend) is an open-source framework that harmonizes access to the above automation techniques and simplifies the transition towards and between them. It is maintained as part of the EURO-LABS project in cooperation between CERN and GSI. In dedicated beam experiments, the beam loss of the multi-turn injection into the SIS18 synchrotron has been reduced from 40% to 10% in about 15 minutes, where manual adjustment can take up to 2 hours. Geoff has also been used successfully at the GSI Fragment Separator (FRS) for beam steering. Further experimental activities include closed orbit correction for specific broken-symmetry high-transition-energy SIS18 optics with Bayesian optimization in comparison to traditional SVD-based correction.
Paper: MOPS68
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-MOPS68
About: Received: 06 May 2024 — Revised: 21 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
TUAD2
Correcting asymmetry of closed-orbit distortion in J-PARC main ring by reducing current ripples of main magnet power supplies
931
The main ring (MR) of the Japan proton accelerator research complex (J-PARC) delivers the high-intensity proton beams to the T2K long-baseline neutrino experiment. To observe charge-conjugation and parity-transformation violation in the lepton sector with high accuracy, the upgrade of the MR toward the beam power of 1.3 MW is mandatory. The magnet power supply system of MR was upgraded for this purpose during the long-term shutdown period in FY2021. However, the asymmetry of the closed-orbit distortion (COD) was observed after the upgrade. The cause of the asymmetry was attributed to the large ripples of the excitation currents for the bending magnets. The measures to reduce the ripples were applied to six identical power supplies for the bending magnets, and then the asymmetry was successfully corrected. This result suggests the tune region of the stable beam operation is expected to be improved since the effect of the non-structure resonance should be suppressed. This presentation reports the scheme of the ripple reduction for the excitation currents of the bending magnets and the measurement results of the COD in the MR.
Paper: TUAD2
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUAD2
About: Received: 14 May 2024 — Revised: 24 May 2024 — Accepted: 24 May 2024 — Issue date: 01 Jul 2024
TUAN1
Beam loss and beam emittance minimization at J-PARC RCS for simultaneous operation to the MLF and MR
939
The 3-GeV RCS (Rapid Cycling Synchrotron) at J-PARC (Japan Proton Accelerator Research Complex) simultaneously delivers high-intensity proton beam to the muon and neutron production targets at the MLF (Material and Life Science Experimental Facility) as well as to the MR (Main Ring). Beam loss mitigation is highly essential not only to keep the machine activation lower for maintaining a stable operation with high availability, but also to ensure a high-quality beam having a lower beam emittance and minimum beam halos. We have performed systematic numerical simulations and beam studies and implemented several measures, such as resonance corrections, optimization of the longitudinal and transverse paintings and also optimization of the betatron tune. We have obtained significant beam loss mitigation as well as beam emittance improvement for the beam delivered to both MLF and the MR. Recently, a transverse painting area of 50π mm·mrad has been increased to 100π mm·mrad implemented for the MR beam. This gives a half reduction of the average foil hitting of the circulating beam. As a result, not only the uncontrolled foil scattering beam losses but also the beam loss at the collimator have been reduced to half. Such improvements in the RCS have also been well recognized at both MLF and the MR by reducing the beam losses at the beam transport as well as each facility. The RCS has been continued a sustainable operation with record high of nearly 99% availability.
Paper: TUAN1
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUAN1
About: Received: 15 May 2024 — Revised: 18 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
TUBD2
Analysis of the performance in the 2023 LHC Pb-Pb run
955
In 2023, the Pb-Pb run in the Large Hadron Collider (LHC) took place during the last five weeks of operation at a record beam energy of 6.8 Z TeV. It marked the first heavy-ion run of Run 3, following a two-day test that took place in 2022 to verify some key machine and beam upgrades. The 2023 run profited for the first time of higher beam intensities than the previous runs and of machine upgrades that enable higher peak luminosities in the ion-dedicated ALICE experiment. This paper addresses two important performance aspects: firstly, it compares the achieved operational efficiency for the different filling schemes employed during the run, and secondly, it quantifies the main factors contributing to performance loss.
Paper: TUBD2
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUBD2
About: Received: 07 May 2024 — Revised: 21 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
TUPC02
Design of a two-cell C-band accelerator cavity with higher-order mode damping
989
Higher-order mode (HOM) damping is essential for building large-scale facility linear accelerators, such as a linear collider, because of the need to reduce the wakefield strength inside the accelerating structure. We designed a C-band accelerator cavity with distributed coupling and thin HOM-damping waveguides oriented in the radial direction. It was proposed that nickel-chrome (NiCr) coating deposited on the surface of the thin waveguides will be used to increase the surface resistivity and to damp the HOMs. Recently, we designed a two-cell cavity to conduct a concise high power test that will help us understand the fabrication challenges for the cavity with NiCr HOM absorbers, and examine the performance of the NiCr coating under high-power conditioning. This presentation will report the detailed electromagnetic and engineering design of the cavity, the theoretical prediction of the cavity high-gradient performance, the status of fabrication, and plans for high-gradient testing.
Paper: TUPC02
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPC02
About: Received: 14 May 2024 — Revised: 20 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
TUPC08
A review of the 2023 antiproton physics run in the CERN antimatter factory
1010
Despite a shorter-than-scheduled physics run due to a hardware problem, the AD/ELENA antiproton complex delivered record beam intensities to the experiments during the 2023 run. This paper reviews the performance of both the CERN Antiproton Decelerator (AD) and the Extra Low ENergy Antiproton (ELENA) decelerator and their associated transfer lines. It presents the main improvements that allowed these record beam intensities to be delivered to the experiments. Emphasis is put on the optimization of the injection line, progress made on the stochastic and electron cooling performance, increased deceleration efficiency and stability, and the software tools used. Remaining issues and potential future improvements for the coming run will also be presented.
Paper: TUPC08
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPC08
About: Received: 07 May 2024 — Revised: 18 May 2024 — Accepted: 18 May 2024 — Issue date: 01 Jul 2024
TUPC09
Flattening the field during injection in the Fermilab booster using dipole corrector magnets
1014
The FNAL Booster is a fast cycling 15 Hz resonant circuit synchrotron accelerating proton beam from 400 MeV to 8 GeV. The linac pulse injected into the Booster is ~32 μsec long and fills the ring by multi-turn charge-exchange injection. As part of the PIP-II project, the Booster injection energy and repetition rate will be increased to 800 MeV and 20 Hz respectively. Due to much reduced average current in the new superconducting PIP-II linac, the injection time will increase to 550 μs. A shorter machine cycle coupled to a longer injection time make flattening the injection porch B-field during injection important requirement for successful PIP-II operation. We aim to achieve: (1) flattening of the net bending during injection using dipole correctors, and (2) using a new system based on an Altera FPGA board, reduction of the cycle-to-cycle bending field variation caused by current jitter in the Gradient Magnet Power Supply (GMPS). While the flat injection scheme is essential to future PIP-II operations, it should also noticeably improve efficiency for present HEP operations.
Paper: TUPC09
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPC09
About: Received: 22 May 2024 — Revised: 23 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
TUPC10
RF system upgrade for 1.3 MW operation of J-PARC main ring
1017
The J-PARC Main Ring accelerates proton beam from 3 GeV to 30 GeV and delivers it to T2K neutrino experiment with fast extraction and hadron experiments with slow extraction. In the last two years the beam power to the neutrino experiment was increased from 500 kW to 750 kW. The T2K detector is scheduled to be replaced by the new Hyper-K detector; the latter will be able to accept a 1.3 MW proton beam by 2028. To achieve 1.3 MW beam power, J-PARC plans to upgrade the Main Ring by increasing intensity and repetition rate. The Main Ring uses low frequency, high bandwidth RF cavities with Magnetic Alloy cores, powered by two 600 kW tetrode tubes. Under the upgrade plan, the number of RF cavities will be increased to secure the RF voltage and longitudinal acceptance. The anode power supply will be upgraded to provide enough current for both gap voltage and beam loading compensation. The upgraded LLRF system will be optimized to control fundamental and 2nd harmonic RF voltages, suppress coupled bunch instabilities and compensate beam loading effects. Current operational status as well as details of the upgrade plan and related simulation results will be discussed in this paper.
Paper: TUPC10
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPC10
About: Received: 20 May 2024 — Revised: 22 May 2024 — Accepted: 22 May 2024 — Issue date: 01 Jul 2024
TUPC19
High-current DC gun for low energy RHIC cooler project
1047
Electron cooling of ion beams employing RF-accelerated electron bunches was successfully used for the RHIC physics program in 2020 and 2021. Electron cooler LEReC uses a high-voltage photoemission electron gun with stringent requirements for beam current, beam quality, and stability. The electron gun has a photocathode with a high-power fiber laser, and a novel cathode production, transport, and exchange system. It has been demonstrated that the high-voltage photoemission gun can continually produce a high-current electron beam with a beam quality suitable for electron cooling. We describe the operational experience with the LEReC dc photoemission gun in RHIC and discuss the important aspects needed to achieve the required beam current, beam quality, and stability. We also present recent gun tests in which stable operation at 50 mA CW beam current was established, as well as future plans.
Paper: TUPC19
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPC19
About: Received: 08 May 2024 — Revised: 21 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
TUPC36
Initial operational experience of an LHC injection kicker magnet upgraded for HL-LHC
1080
The intensity of the HL-LHC beam will be twice that of LHC. Hence, an upgrade of the LHC injection kickers (MKIs) is necessary for HL-LHC to avoid excessive beam induced heating of the MKIs. In addition, any newly installed MKI magnet would limit HL-LHC operation for a few hundred hours due to dynamic vacuum activity. Extensive studies have been carried out to identify solutions to address these problems and they have been implemented in an upgraded LHC injection kicker magnet (MKI Cool): the MKI Cool was installed in the LHC during the 2022-23 Year End Technical Stop. Magnet heating has been reduced by redistributing a significant portion of the beam induced power deposition from the ferrite yoke to a ferrite loaded RF Damper, which is not at pulsed high voltage, and by water cooling of the damper. Furthermore, a surface coating, to mitigate dynamic vacuum activity, has been applied. This paper discusses the upgrades, presents results from the initial operational experience, and compares the predicted and ‘measured’ beam induced power deposition.
Paper: TUPC36
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPC36
About: Received: 12 May 2024 — Revised: 18 May 2024 — Accepted: 18 May 2024 — Issue date: 01 Jul 2024
TUPC38
SPS injection kicker system: 2023 operational experience and upgrade proposals for high-luminosity LHC
1088
The SPS injection kicker system comprises twelve MKP-S (small aperture) modules and four MKP-L (large aperture) modules. An upgraded MKP-L magnet was installed in the SPS, during December 2022, in view of the higher beam intensity needed in the future for High-Luminosity-LHC. The upgrades have significantly reduced the beam coupling impedance and consequent beam induced heating. The improved performance is due to a new beam screen, consisting of silver fingers painted on an alumina chamber, inserted in each magnet’s aperture. Additionally, a surface coating on the chamber's inner surface reduces its secondary electron yield and hence dynamic vacuum activity. The effectiveness of these upgrades was demonstrated during the 2023 operation. This paper provides an in-depth exploration of the initial year of operational experience with the upgraded MKP-L, giving a comparative analysis of dynamic vacuum and beam induced heating with the MKP-S modules. An alternative approach for upgrading the MKP-S modules, to reduce their temperature, is also proposed.
Paper: TUPC38
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPC38
About: Received: 15 May 2024 — Revised: 20 May 2024 — Accepted: 20 May 2024 — Issue date: 01 Jul 2024
TUPC39
Production and validation of the RF cooling damper for the LHC injection kickers
1092
Fast single-turn injection kicker systems deflect incoming beam onto the orbit of the LHC. The higher intensities of High Luminosity (HL) LHC beams are predicted to cause the ferrite yokes of the LHC injection kicker magnets (MKI), in their current configuration, to heat up to their Curie temperature. Studies to reduce the beam induced heating have been carried out over the past years and resulted in a design featuring a water-cooled RF damper. A significant portion of the beam induced power has been relocated from the yoke to a ferrite in the RF damper. The ferrite damper is cooled via a copper sleeve, brazed to the ferrite, via a set of water pipes. The manufacturing of this RF damper system is challenging since different materials are brazed together to form a complex and fragile assembly, optimized for heat transfer, installed in an ultra-high vacuum environment. This paper outlines fabrication methods and their reproducibility, compares the results of measurements of the thermal interface between the ferrite and copper sleeve, and concludes on the challenges of assuring a production technique that results in a reliable and suitable thermal interface.
Paper: TUPC39
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPC39
About: Received: 15 May 2024 — Revised: 23 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
TUPC47
SoC based time-resolved scaler DAQ and amplifier-discriminator upgrade for laser spectroscopy
1115
The BEam COoler and LAser spectroscopy (BECOLA) is a collinear laser spectroscopy facility at the Facility for Rare Isotope Beams (FRIB) at Michigan State University. Time resolved laser spectroscopy experiments are performed here to study the nuclear structure of radioactive isotopes. The current data acquisition (DAQ) system being used is based on AMD Spartan 6 field programmable gate array (FPGA) and has a time resolution of 8 ns. There was a need to upgrade existing hardware to meet the requirements for higher time resolution of fast ion detectors. A new DAQ system with AMD Zynq System on Chip (SoC) FPGA based time-resolved scaler was designed, developed and fabricated. It achieves a time resolution of 2 ns. The current amplifier-discriminator has an output pulse resolution of 10 ns. To address this constraint and fully leverage the 2 ns time resolution provided by the new SoC FPGA, a new AD with an output pulse resolution of 1 ns was designed. A brief overview of the upgraded DAQ system will be discussed in this paper, including its features, improvements and future updates.
Paper: TUPC47
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPC47
About: Received: 15 May 2024 — Revised: 21 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
TUPC66
Energy deposition and radiation level studies for the FCC-ee experimental insertions
1152
The Future Circular Collider (FCC) study foresees the construction of a 90.7 km underground ring where, as a first stage, a high-luminosity electron-positron collider (FCC-ee) is envisaged, operating at beam energies from 45.6 GeV (Z pole) to 182.5 GeV (ttbar). In the FCC-ee experimental interaction regions, various physical processes give rise to particle showers that can be detrimental to machine components as well as equipment in the tunnel, such as cables and electronics. In this work, we evaluate the impact of the synchrotron radiation (SR) emitted in the magnets and the beamstrahlung (BS) radiation from the interaction point (IP). The Monte Carlo code FLUKA is used to quantify the power deposited in key machine elements, such as the BS dump, as well as the cumulative radiation levels in the tunnel. We also examine the effect of SR absorbers in the vacuum chamber and of external tungsten shielding. The results are presented for the different operation modes, namely Z pole and ttbar.
Paper: TUPC66
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPC66
About: Received: 13 May 2024 — Revised: 22 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
TUPC71
Optics rematching between TT24 and P42 primary beam lines within the HI-ECN3 study project at CERN
1172
The High Intensity ECN3 (HI-ECN3) study project aims to increase the intensity of the proton beam delivered to a new experimental facility housed in the ECN3 underground cavern in CERN’s North Area up to the ~4e+13 ppp (protons per pulse) and up to ~4e+19 POT (protons on target) per year. The increase necessitates upgrades of the primary beam transfer lines coming from SPS directly to the new Target Complex upstream of ECN3. In this work we describe the modifications to the primary beam line optics that allow the transfer of the beam to the HI-ECN3 facility in two scenarios: shared (beam is split between the three existing production targets) and dedicated (beam goes directly to the target serving ECN3). An optimization study is presented to reduce the sensitivity of the beam optics to errors and minimize the effects of the beam’s interaction with material when transiting the existing target area between TT24 and P42, whilst respecting the different constraints needed to share the beam between ECN3 and the rest of the North Area and permit a vertical trajectory bump around the target serving EHN1.
Paper: TUPC71
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPC71
About: Received: 15 May 2024 — Revised: 23 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
TUPC72
Improvements of the SPS slow extraction electrostatic septum
1176
The impact of high-flux protons on the inherent beam loss in the slow extraction from SPS towards the North Area has been recently discussed and potential improvements have been proposed. These solutions are mainly aiming to reduce the high component activation and related reduction of lifetime, as well as observed non straightness in the anode body. Recent studies have allowed to demonstrate feasibility of replacing the currently installed stainless steel tank, flanges, and anode body by lowZ materials. The design iteration and material choice has led to the fabrication of a reduced length prototype, demonstrating mechanical, electrical, as well as the vacuum related performance. The mass reduction of the anode body has been optimized using numerical simulation, considering mechanical and thermal constraints. The paper presents the development of the vacuum vessel, including numerical analysis. The results from the design and prototype tank fabrication will be compared to the existing system. Furthermore, the optimization of the anode body and potential fabrication based on additive manufacturing including 3d optical straightness metrology will be discussed.
Paper: TUPC72
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPC72
About: Received: 15 May 2024 — Revised: 28 May 2024 — Accepted: 29 May 2024 — Issue date: 01 Jul 2024
TUPC75
HL-LHC series collimators: key technical requirements, crucial production challenges and risk mitigation plan
1188
In view of High Luminosity (HL) - Large Hadron Collider (LHC) project, an upgraded collimation system has been developed to accommodate a rise of ten times of the integrated luminosity compared to the LHC. A new series of collimators will be produced and installed in the machine during the Long Shutdown 3 (LS3) to take place during 2026-2028. The updated design incorporates cutting-edge technologies to meet the demanding operating requirements. Multiple production activities are recognized as critical to ensure the quality of the collimators. Comprehensive qualification checks of the production procedures are planned, and functional tests will be conducted to validate the performance of each unit produced.
Paper: TUPC75
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPC75
About: Received: 14 May 2024 — Revised: 24 May 2024 — Accepted: 24 May 2024 — Issue date: 01 Jul 2024
TUPC79
Future upgrades for GANIL
1199
We will present the plans and ideas for the next upgrades as discussed for the GANIL-SPIRAL2 installation in France. Recently, a report "French roadmap for Nuclear, Particle, and Astroparticle physics, along with associated technical developments and applications." were produced. It particularly focused to “The future of GANIL”. This was further enriched through extensive discussions by an international expert committee led by Michel SPIRO. These endeavors aim to push the boundaries of research capabilities at GANIL-SPIRAL2 during the next decades. Since the starting up in 1983, 40 years ago, successful exploitation with stable beams at the cyclotrons of GANIL, the laboratory has continuously evaluated and enhanced its capabilities. The latest evolution was the starting up of the SPIRAL2 facility. Today GANIL, with its state-of-the-art installations, including cyclotrons, a linear accelerator, and experimental areas, presents unique opportunities for cutting-edge research. The next upgrades under discussion are to be presented. Involving increasing beam intensities, exploring new exotic nuclei. Endeavors that aim to push the boundaries of research capabilities at GANIL-SPIRAL2 for the next decades.
Paper: TUPC79
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPC79
About: Received: 15 May 2024 — Revised: 19 May 2024 — Accepted: 19 May 2024 — Issue date: 01 Jul 2024
TUPG01
Dismantle, assembly and installation plans for the ALBA II upgrade
1217
The 3.0 GeV ALBA Synchrotron Light Source, in operation with users since 2012, is looking forward an upgrade aimed at enhancing the brightness and coherence fraction of the delivered X-ray beam. The Storage Ring (SR) will be completely renewed but we plan on keeping the same orbit length and the position of the ID source points. The energy of the electrons will be preserved and the same injector will be used. Major part of the Insertion Devices and Front Ends will be kept; new ones will feed additional long Beamlines (230m-275m), included on the project. The “dark period” is foreseen for 2030-2031. This paper presents the strategic plans being developed to test and assemble the new SR components, the dismantling of the present SR and the seamless installation of the upgraded SR. Emphasizing a cost-effective and time-efficient approach, we have started the planning by focusing on optimizing spaces and equipment movements necessary for the upgrade process.
Paper: TUPG01
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPG01
About: Received: 10 May 2024 — Revised: 20 May 2024 — Accepted: 20 May 2024 — Issue date: 01 Jul 2024
TUPG06
Particle accumulator ring restart and readiness for Advanced Photon Source upgrade commissioning
1228
At the Argonne (ANL) Advanced Photon Source (APS), a 425-MeV Particle Accumulator Ring (PAR) is used to stack 1-nC electron pulses from the linac and inject a single bunch into the booster at a 1-Hz repetition rate. All the APS injectors, including PAR, were shut down in April 2023 at the start of the APS Upgrade Dark Time. In this paper, we report on PAR re-start activities starting in Oct. 2023. The PAR vacuum pressure was unexpectedly high when first powering the fundamental and harmonic radiofrequency (rf) systems, as well as when first injecting the beam, which initially limited both the beam charge and rf gap voltage. These limits were overcome through many weeks of systematic rf and vacuum conditioning. Additional restart activities include commissioning two new kicker chambers with a special low-impedance, eddy-current-suppressing coating, commissioning of the digital low level rf system, and tests with the Injection Extraction Timing and Synchronization (IETS) system. We demonstrated initial APS-U commissioning performance goals: a stable, 5-nC injected bunch charge with a bunch length short enough for injection into the booster.
Paper: TUPG06
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPG06
About: Received: 15 May 2024 — Revised: 21 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
TUPG09
Conceptual design of a future Australian light source
1236
Conceptual design work is under way for a fourth generation light source in Australia.This new light source is being designed as a completely new facility, intended to come into operation around 2037 as the current Third generation Australian Synchrotron reaches its end of life. Previous design work was done to consider a 600 m ring, but on review the decision was made to reduce the circumference to 450 m. This paper will outline the main design considerations, initial lattice design and technology choices currently under consideration.
Paper: TUPG09
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPG09
About: Received: 16 May 2024 — Revised: 22 May 2024 — Accepted: 22 May 2024 — Issue date: 01 Jul 2024
TUPG14
Beam centroid studies at the Canadian Light Source
1243
The Canadian Light Source (CLS) storage ring RF frequency varies on timescales of seconds to days. Over approximately 20 years it has drifted from its design value. We outline and discuss our efforts to identify, disentangle and mitigate the potential sources of variations in the RF frequency on various timescales. These sources include the building temperature regulation, the orbit correction algorithm and the dipole power supply. Further, orbit correction generates an undesirable amount of beam noise through the dispersion correction. We have ongoing efforts to understand and improve orbit correction and remove the noise it propagates into the RF frequency.
Paper: TUPG14
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPG14
About: Received: 14 May 2024 — Revised: 21 May 2024 — Accepted: 22 May 2024 — Issue date: 01 Jul 2024
TUPG25
Operation and developments at the ESRF-EBS light source
1270
The European Synchrotron Radiation Facility - Extremely Brilliant Source (ESRF-EBS) is a facility upgrade allowing its scientific users to take advantage of the first high-energy 4th generation storage ring light source. In December 2018, after 30 years of operation, the beam stopped for a 12-month shutdown to dismantle the old storage ring and to install the new X-ray source. On 25th August 2020, the user program restarted with beam parameters very close to nominal values. Since then beam is back for the users at full operation performance and with an excellent reliability. This paper reports on the present operation performance of the source, highlighting the ongoing and planned developments and the sustainability efforts.
Paper: TUPG25
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPG25
About: Received: 10 May 2024 — Revised: 20 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
TUPG29
Present status and future project of Synchrotron Light Sources at KEK
1286
Two synchrotron radiation sources, the 2.5 GeV Photon Factory Storage Ring (PF ring) and the 6.5 GeV Photon Factory Advanced Ring (PF-AR), have been in stable operation at the High Energy Accelerator Research Organization (KEK) for over 40 years. This paper first describes the current operational status and recent developments at PF. Next, a new concept of hybrid light source (PF-HLS) combining the advantages of a superconducting linac and a low-emittance storage ring is described. In the preliminary design, the energy range is from 2.5 GeV to 5.0 GeV, and the storage ring will be constructed in a green field with a circumference of 750 m. The design baseline for superconducting linac uses the International Linear Collider (ILC) specifications.
Paper: TUPG29
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPG29
About: Received: 15 May 2024 — Revised: 16 May 2024 — Accepted: 16 May 2024 — Issue date: 01 Jul 2024
TUPG35
ALS-U accumulator ring raft and dipole installation
1302
The ALS-U project is an upgrade to the Advanced Light Source (ALS) at the Lawrence Berkeley National Laboratory that aims to deliver diffraction-limited x-ray beams with an increased beam brightness of two orders of magnitude for soft x-rays compared to the current ALS facility. A nine-bend achromat lattice Storage Ring (SR) and a three-bend achromat Accumulator Ring (AR) will be installed in the facility in two phases. The AR is currently being installed in the ALS facility during its regularly planned shutdowns while the SR upgrade will follow during a 12 months shutdown. AR rafts and dipoles are being installed with ground based tooling and overhead crane lifting methods. This paper focuses on the AR installation. In particular we will describe the engineering design, prototyping and testing of the customized ground based installation tooling, which led to a successful installation of the first AR production rafts and dipoles in the ALS tunnel.
Paper: TUPG35
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPG35
About: Received: 15 May 2024 — Revised: 20 May 2024 — Accepted: 20 May 2024 — Issue date: 01 Jul 2024
TUPG36
Beam-based girder alignment to reduce corrector strengths: conceptual simulations for PETRA IV
1305
DESY is planning to upgrade PETRA III to a 4th generation light source. The magnetic lattice components are pre-installed and aligned on long girders before being installed in the tunnel. These long girders and the misalignment of the magnets pose a challenge for the PETRA IV lattice, including the storage of the beam in the ring. Commissioning simulations have been performed which showed that relatively high corrector strengths are required for the orbit correction system. A simulation study was performed to demonstrate the possibility of beam-based girder alignment correction to relax the corrector strengths during machine operation. The simulation results are presented and then discussed for later implementation.
Paper: TUPG36
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPG36
About: Received: 15 May 2024 — Revised: 17 May 2024 — Accepted: 17 May 2024 — Issue date: 01 Jul 2024
TUPG37
Status of the Advanced Light Source
1309
The LBNL Advanced Light Source, a pioneering third-generation soft x-ray synchrotron radiation source operating at 1.89 GeV with a 2~nm beam emittance, stands as one of the earliest facilities in its class, continually evolving to maintain its status at the forefront of soft x-ray sources. This paper reviews the most significant advancements in the accelerator's hardware and software infrastructures and presents the machine operational statistics over the last 15 years.
Paper: TUPG37
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPG37
About: Received: 12 May 2024 — Revised: 19 May 2024 — Accepted: 20 May 2024 — Issue date: 01 Jul 2024
TUPG39
Improve the injection with high energy for CAMD light source
1317
With Insertion devices adapted to Center of Advanced Microstructures and Devices (CAMD) light source. Injection has more difficulties at low energy. We have proposed some upgrade to the facility, but we would like to look for other choices. In the paper, we will mention the CAMD operation status, discuss raising electron energy method for injection, and simulate the transfer line. The practical upgrade will be proposed. The injection lattice at high electron energy will be available. The kicker parameter will be given.
Paper: TUPG39
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPG39
About: Received: 14 May 2024 — Revised: 20 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
TUPG40
Status of beam commissioning at NanoTerasu
1320
NanoTerasu is a new 3 GeV compact soft X-ray (SX) light source having a circumference of 349 m constructed in Japan. The lattice structure is a type of multi-bend achromat with design emittance values of 1.14 nm·rad and 10 pm·rad, respectively. A target stored current is set to 400 mA to provide a high coherence and highly brilliant light from extreme ultraviolet to SX range. The injector LINAC commissioning was started in April 2023. After first 10 days, the beam energy successfully reached 3 GeV with the designed emittance. The 3 GeV C-band full-energy injector LINAC enables the extension to the SX free electron laser in the future. The storage ring beam commissioning was started on June 8th. We achieved the off-axis beam injection just adjusting beam injection trajectory from the beginning of the beam commissioning. As a result of the precise alignment of the magnets, the injected beam turned around 300 turns without the supply of RF power and the adjustment of the steering magnets on the first day of the commissioning. The stored current was reached 300 mA with top-up beam injection in November. The user operation will be started in April 2024. The creation of COD and tune correction tables for the insertion device is also in progress including non-linear magnetic field correction. We try to start the user operation with designed 400 mA top-up beam injection. The status of beam commissioning will be presented.
Paper: TUPG40
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPG40
About: Received: 12 May 2024 — Revised: 20 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
TUPG41
Study of an upgraded lattice for Taiwan Photon Source
1324
In pursuit of maximizing the performance of the Taiwan Photon Source (TPS), we conducted a feasibility study aimed at reassessing and optimizing the lattice configuration within the existing tunnel infrastructure. One of our main objective is to minimize displacement of source points for insertion devices (IDs) while augmenting overall beam performance. To achieve this, we propose an upgraded lattice design based on the multi-bend achromatic (MBA) scheme, featuring 5 bending achromat (5BA) in each arc. This report discusses the challenges encountered and presents preliminary results regarding the implementation of this 5BA lattice design.
Paper: TUPG41
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPG41
About: Received: 13 May 2024 — Revised: 16 May 2024 — Accepted: 16 May 2024 — Issue date: 01 Jul 2024
TUPG46
Error analysis and commissioning simulations for the SSRF-U lattice
1342
SSRF-U, a 3.0 GeV diffraction limited storage ring lattice with emittance of 53.2 pm∙rad, is an alternative to SSRF for future upgrades. A large number of high-field intensity and multi-function magnets are used in this compact lattice, which greatly increases the error sensitivity to the beam. To quickly complete beam commissioning and achieve stable operation in the future, error analysis and commissioning simulations were studied during the design phase. In this paper, we present commissioning simulations for the SSRF-U and analyze the lattice error acceptance depending on the simulation results at each stage.
Paper: TUPG46
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPG46
About: Received: 14 May 2024 — Revised: 20 May 2024 — Accepted: 20 May 2024 — Issue date: 01 Jul 2024
TUPG48
Operational status of synchrotron SOLEIL
1350
The synchrotron SOLEIL is the French third-generation 2.75 GeV synchrotron light source, a research laboratory at the forefront of experimental techniques for the analysis of matter down to the atomic level, and a service platform open to all scientific and industrial communities. We present the performance of the accelerators, which deliver extremely stable photon beams to 29 beamlines. We report on last year's overall performance figures and the operation of the brand-new cooling station. As the optimization of the energy and carbon footprint becomes more and more prevalent in France and Europe, actions for a more sustainable operation are given. Several incidents are also presented, together with the lessons learned to avoid recurrence. Major research and development activities related to component obsolescence and the SOLEIL II project will also be presented.
Paper: TUPG48
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPG48
About: Received: 20 May 2024 — Revised: 21 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
TUPG55
Force-neutral adjustable phase undulator
1372
A Force-Neutral Adjustable Phase Undulator (FNAPU) has been constructed at the Advanced Photon Source. The FNAPU is a 2.4-meter-long planar hybrid permanent magnet undulator with a 27-mm period length and a fixed gap of 8.5 mm. It consists of two magnetic assemblies with matching periods: one featuring an undulator magnetic structure and the other a simpler magnet structure to compensate the force of the undulator. The magnetic field measurement results of the undulator will be presented.
Paper: TUPG55
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPG55
About: Received: 13 May 2024 — Revised: 16 May 2024 — Accepted: 17 May 2024 — Issue date: 01 Jul 2024
TUPG58
Magnetic characterization and phase error tuning of a 1.5 m long NbTi SCU at the Advanced Photon Source
1383
Prior to assembly into the operational cryostat each superconducting undulator (SCU) at the Advanced Photon Source undergoes testing in a LHe bath cryostat where coil training and magnetic measurements are performed. If necessary, the baseline magnetic measurements are used for phase error tuning which is achieved by adjusting the magnetic gap of the SCU at prescribed locations. An optimization routine using a genetic algorithm is used to determine the magnitude of the gap change. Once complete, the SCUs are incorporated into the production cryostat and magnetic measurements of the final assembly are performed. Details of the process during phase error tuning and LHe bath testing of a 1.5 m-long SCU magnet are presented.
Paper: TUPG58
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPG58
About: Received: 15 May 2024 — Revised: 18 May 2024 — Accepted: 19 May 2024 — Issue date: 01 Jul 2024
TUPG61
New insertion device control system for the APS upgrade
1394
New Hybrid Permanent Magnet Undulators (HPMUs) have been designed and manufactured using servo motors for precise and reliable gap motion control for the Advanced Photon Source Upgrade (APS-U) project. Meanwhile, existing HPMUs equipped with legacy stepper motors are systematically replaced with servo motors. In parallel with mechanical modifications of the undulators, a comprehensive upgrade has been implemented for the control of the devices. This upgrade includes integration of standardized industrial components for replacement of motor controllers and motor drives using the Kollmorgen Programmable Controller Multi-axis Master (PCMM) controllers and the AKD2G series servo drives. Soft Input Output Controllers (IOCs) are developed and deployed to replace the legacy VME-based IOCs for both single-period undulators and Revolver undulators. In this paper, we will present the architecture of the new insertion device control system, including control mechanisms, interlock protocols, and tools for diagnostics and troubleshooting.
Paper: TUPG61
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPG61
About: Received: 15 May 2024 — Revised: 18 May 2024 — Accepted: 18 May 2024 — Issue date: 01 Jul 2024
TUPG64
Integrated Hall probe and stretched wire measurement system for an in-vacuum undulator
1398
Taiwan Photon Source (TPS) is a 3 GeV synchrotron light source at the National Synchrotron Radiation Research Center (NSRRC) in Taiwan. Several in-vacuum undulators are expected to be installed before the end of 2024. Before installation in the storage ring, an in-vacuum undulator's magnetic field has been measured at operational gaps. In order to assess the performance of the in-vacuum undulator, we integrated two measurement methods in the vacuum chamber: one is the SAFALI (Self Aligned Field Analyzer with Laser Instrumentation) system to measure the magnetic field, and the other is the stretched wire system to measure the magnetic field integral. In this work, we designed a stretched wire measurement system integrated with the SAFALI system inside the vacuum chamber. This measurement system was applied to the in-vacuum undulator with a period of 22mm and a magnetic length of 2 m.
Paper: TUPG64
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPG64
About: Received: 08 May 2024 — Revised: 19 May 2024 — Accepted: 20 May 2024 — Issue date: 01 Jul 2024
TUPG65
Multiphysics design of a high heat-load superconducting undulator
1402
RadiaBeam is developing and manufacturing a 15-mm period, 1.15 T high temperature superconductor undulator using Magnesium Diboride (MgB2) wire to operate in a temperature range of 10 K - 15 K. This temperature range can be achieved by a cryocooler, a simpler and less expensive cryogenic solution compared to a liquid helium approach. As the supported current density, and ultimately the quench behavior of MgB2 wire, is a combined problem of magnetic field, tensile stress, tensile strain and temperature, a multiphysics approach is required. We will present the details of this multiphysics design addressing the magnetic, mechanical and thermal engineering challenges, along with the devices anticipated performance characteristics.
Paper: TUPG65
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPG65
About: Received: 15 May 2024 — Revised: 19 May 2024 — Accepted: 19 May 2024 — Issue date: 01 Jul 2024
TUPR01
RF power station stabilization techniques and measurements at LNF-INFN
1417
In the framework of EuPRAXIA@SPARC_LAB project, we are studying possible solutions to upgrade and measure the amplitude and phase stability of the RF accelerating fields generated by a klystron. These studies concern the C- and X- band klystrons installed in the LNF infrastructures. In particular, we will present our work on a fast phase feedback around the C-band power station (50 MW klystron and solid state modulator) installed at SPARC_LAB. We are trying to push the timing jitter below the standard limit of such systems (few tens of fs RMS). A second topic is the study of the jitter of the X-band power station (50 MW klystron and solid state modulator) installed in the TEX facility. Precise measurements on amplitude and phase of this system will be reported at different positions both upstream (LLRF and pre-amp) and downstream (waveguides and prototype structure) the klystron.
Paper: TUPR01
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPR01
About: Received: 09 May 2024 — Revised: 20 May 2024 — Accepted: 20 May 2024 — Issue date: 01 Jul 2024
TUPR02
Advancements in X-band technology at the TEX facility at INFN-LNF
1421
In anticipation of the Eupraxia@SPARC_LAB project at the INFN Frascati National Laboratories, an intensive testing and validation activity for the X-band RF system has commenced at the TEX test facility. The Eupraxia@SPARC_LAB project entails the development of a Free-Electron Laser (FEL) radiation source with a 1 GeV Linac based on plasma acceleration and an X-band radiofrequency (RF) booster. The booster is composed of 16 high-gradient accelerating structures working at 11.994GHz. All radiofrequency components comprising the basic module of the booster, from the power source to the structure, must undergo testing at nominal parameters and power levels to verify their reliability. For this reason, since 2021, several experimental runs have been conducted to test various components in X-band technology at the TEX facility. This paper presents the results obtained thus far from the different experimental runs, and it also outlines the future upgrade of the facility, which will enhance testing capabilities and the future prospects of the facility itself.
Paper: TUPR02
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPR02
About: Received: 15 May 2024 — Revised: 21 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
TUPR04
Preserving restoring and conditioning the RF cavities of the storage ring for the Advanced Photon Source upgrade
1425
The Advanced Photons Source (APS) storage ring (SR) underwent an upgrade to the multi-bend achromat (MBA) lattice recently. As part of the upgrade, four out of the sixteen Radio Frequency (RF) cavities were removed from the storage ring. The remaining twelve cavities were left in place during the entire upgrade process and restored to full operating power to support beam commissioning once the installation activities were completed. This paper provides details on the planning and preparations made to preserve the cavity integrity during the installation period, challenges faced while restoring the cavities and how the cavity power coupler beta values were determined.
Paper: TUPR04
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPR04
About: Received: 15 May 2024 — Revised: 24 May 2024 — Accepted: 24 May 2024 — Issue date: 01 Jul 2024
TUPR07
Development of a spill-structure manipulation cavity and first experiment with beam in SIS18
1432
For several years, significant effort has been spent at GSI to improve the time structure of the spill during slow extraction in SIS18. This led to the requirement to extend the possibilities to experimentally improve the micro-spill structure by partially or fully capturing the beam with an RF of more than 40 MHz. Therefore, a so-called spill-structure manipulation cavity was designed, realized and optimized which allows the mentioned experiments. In this contribution, the design of the cavity and the challenges of its realization are described, and measurement results concerning the first experimental operation in the SIS18 synchrotron are presented.
Paper: TUPR07
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPR07
About: Received: 14 May 2024 — Revised: 22 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
TUPR10
Preliminary results on X-Band structures for the Eupraxia@SPARC_LAB project
1436
The Eupraxia@SPARC_LAB project involves the development of a 1 GeV normal conducting Linac with an S-band injector followed by an X-band booster. To achieve the final energy, the booster consists of 16 traveling wave accelerating structures operating at 11.994 GHz with a minimum working gradient of 60 MV/m. An intensive design activity, prototyping, and testing of these structures is underway at INFN-LNF. This paper comprehensively presents all the work conducted in the design and prototyping, along with preliminary test results obtained from the first RF prototype of the Eupraxia@SPARC_LAB X-band accelerating structure.
Paper: TUPR10
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPR10
About: Received: 15 May 2024 — Revised: 21 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
TUPR12
Conceptual design of an 805 MHz cavity with beryllium windows and distributed coupling
1444
For the future multi-TeV muon collider, ionization cooling is a critical step to achieve the required beam emittance for a proton-driven muon beam. Ionization cooling of intense muon beams requires the operation of high-gradient, normal-conducting RF structures in the presence of strong magnetic fields. The MAP modular cavity study at Fermilab has demonstrated the RF breakdown threshold at 13 MV/m for copper surface and 50 MV/m for beryllium surface in a 3 T solenoid B field. Based on these surface E field limits, we design a new 805 MHz copper cavity with thin curved beryllium windows that can achieve a gradient (without the transit time factor) of ~27 MV/m, which is comparable to the current 6D cooling lattice design. We also explore the distributed coupling for feeding the RF power to multiple cavities in the cooling lattice to accommodate the tight space in the superconducting solenoids. This cavity design study can be applied to the muon collider demonstrator program to experimentally evaluate the 6D muon emittance cooling.
Paper: TUPR12
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPR12
About: Received: 16 May 2024 — Revised: 20 May 2024 — Accepted: 22 May 2024 — Issue date: 01 Jul 2024
TUPR19
Design of an X-band parallel-coupled accelerating structure for future linacs
1454
As compared to conventional travelling-wave (TW) structures, parallel-coupled accelerating structures eliminate the requirement for the coupling between cells, providing greater flexibility in optimizing the shape of cells. Each cell is independently fed by a periodic feeding network for this structure. In this case, it has a significantly short filling time which allows for ultrashort pulse length, thereby increasing the achievable gradient. In this paper, a design of an X-band parallel-coupled TW structure is presented in detail.
Paper: TUPR19
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPR19
About: Received: 14 May 2024 — Revised: 21 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
TUPR22
New design techniques on matching couplers for travelling wave accelerating structures
1464
Numerical optimizations on couplers of the traveling wave accelerating structures usually require lots of calculation resources. This paper proposes a new technique for matching couplers to an accelerating structure in a more efficient way. It combines conventional Kroll method with improved Kyhl method, thereby simplifying the tuning and simulation process. We will present the detailed design of a constant-gradient C-band accelerating structure based on this new method.
Paper: TUPR22
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPR22
About: Received: 14 May 2024 — Revised: 21 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
TUPR24
Solid state amplifier project at the Advanced Photon Source
1470
The Advanced Photon Source at Argonne National Laboratory (ANL) is in the process of acquiring solid state amplifiers (SSA) from R&K Limited to replace four 1MW klystron rf systems that provide rf power to the storage ring cavities. This project is necessary primarily due to klystron obsolescence. Based on present needs for the APS Upgrade, twelve 160kW SS rf amplifier systems will be required to replace the legacy klystrons. Each of the 352-MHz SSA systems consist of a rack-mounted control unit, two 85kW amplifier cabinets, four 48-way coaxial combiners, and a single 4-way waveguide final combiner. The system is designed with particular attention to reliability and redundancy to help ensure high reliability metrics for the APS-U rf system.
Paper: TUPR24
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPR24
About: Received: 09 May 2024 — Revised: 17 May 2024 — Accepted: 17 May 2024 — Issue date: 01 Jul 2024
TUPR25
A power amplifier based on rad-hard gallium nitride FETs for the 10 MHz cavities of the CERN proton synchrotron
1474
The upcoming High-Luminosity Large Hadron Collider (HL-LHC) program requires a beam performance in the CERN Proton Synchrotron (PS) that is at the limits of the current RF systems. Following the discontinuation of the RF tube production of the driver amplifiers a new solid-state design has been developed using radiation-hard amplifier technology. In view that the current system architecture has reached its maximum achievable gain, the goal was to reduce the cavity impedance encountered by high-intensity circulating beams. This reduction is achieved by increasing the fast feedback gain around the 10 MHz cavities. A 400W modular driver amplifier based on GaN technology and its control system have been prototyped and are currently in the testing phase. The FETs have been qualified for radiation in J-PARC and they will undergo additional irradiation time in the PS tunnel at CERN to additionally qualify the amplifier in its entirety. The paper outlines the modeling phase, the challenges encountered during prototyping, and the achieved results.
Paper: TUPR25
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPR25
About: Received: 14 May 2024 — Revised: 22 May 2024 — Accepted: 22 May 2024 — Issue date: 01 Jul 2024
TUPR27
The MESA high power 1.3 GHz CW solid state power amplifier systems
1482
The Mainz Energy recovering Superconducting Accelerator MESA is a multi-turn energy recovery linac with beam energies in the 100 MeV regime currently under construction at Institut für Kernphysik (KPH) of Johannes Gutenberg-Universität Mainz. The main accelerator consists of two superconducting Rossendorf type modules, while the injector MAMBO (MilliAMpere BOoster) relies on normal conducting technology. The high power RF system is relying completely an solid state technology. After some in-depth testing of a 15 kW prototype amplifier in 2017-2019 a modified version of the amplifier modules was developed. In 2020 series production has begun at JEMA France and first amplifiers, a 74 kW, a 56 kW and two 15 kW have been delivered to KPH lately. In this paper we will present the results of the performance measurements of the amplifiers.
Paper: TUPR27
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPR27
About: Received: 13 May 2024 — Revised: 18 May 2024 — Accepted: 18 May 2024 — Issue date: 01 Jul 2024
TUPR32
Operation of TPS 300 kW solid-state amplifier
1492
The National Synchrotron Radiation Research Center (NSRRC) has developed a 300 kW solid-state amplifier. This 300 kW solid-state amplifier RF transmitter has been operating continuously since August 2023, consistently delivering an output of 250 kW RF power during user beam time at 500 mA. This report describes the performance of the solid-state amplifier RF transmitter during this period, module failure rates, and specific instances of malfunction.
Paper: TUPR32
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPR32
About: Received: 13 May 2024 — Revised: 16 May 2024 — Accepted: 16 May 2024 — Issue date: 01 Jul 2024
TUPR40
Development of prototype magnets for the ultralow emittance storage ring ALBA II
1502
The ALBA synchrotron light source is in the process of a significant upgrade, aiming to become a fourth-generation facility by reducing its emittance by at least 20 times. The initial phase of this project involves a comprehensive prototyping program designed to validate various critical technologies, such as magnets, vacuum systems, girders, etc., essential for facilitating the impending upgrade. This paper focuses on the development of the prototype magnets to implement the MBA lattice designed by our Beam Dynamics group. The lattice presents unique challenges, notably a remarkable degree of compactness necessitating magnet-to-magnet distances of just a few centimeters. Additionally, stringent strength requirements are imposed on both the quadrupolar (up to 110 T/m) and the sextupolar (up to 5000 T/m²) magnets. In this paper we will describe the design details of the initial set of resistive-type prototypes, as well as the preliminary efforts to develop alternative designs making use of permanent magnets. This dual-track approach reflects our dedication to both conventional methods and innovative solutions for the upgraded storage ring.
Paper: TUPR40
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPR40
About: Received: 15 May 2024 — Revised: 18 May 2024 — Accepted: 18 May 2024 — Issue date: 01 Jul 2024
TUPR51
Design of permanent dipole magnet in transport line for TPS
1537
To reduce the electric power consumption and advance the magnetic stability, a prototype of BTS dipole magnet in TPS transfer line between booster and storage ring came into sight. An 1 m long, high current dipole will be replaced by a permanent magnet with Sm2Co17. The new permanent dipole magnet will decrease total volume compared with original electric one, and the homogeneity of integral field is promoted as well. With simulation, the assembly deviation was also discussed. This article presents the magnet circuit design status of prototype to upgrade the transport line in TPS.
Paper: TUPR51
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPR51
About: Received: 14 May 2024 — Revised: 16 May 2024 — Accepted: 17 May 2024 — Issue date: 01 Jul 2024
TUPR56
Solder joint cryogenic fatigue of the RHIC 12x150A current leads and mitigation for future operation
1556
A failure of the RHIC powering system occurred at the end of run 23 and led to the discovery of ruptured con-ductors on the 12x150A current leads used to feed cur-rent to the superconducting (SC) magnet circuits. These ruptured conductors are thought to have led to an electri-cal breakdown, first within the solder joint, and then across adjacent conductors of the same current lead assembly. A fatigue experiment has been set up to study the behavior of Sn96Ag4 solder joints under cycling load at cryogenic temperature. Mitigation measures to mini-mize further fatigue cycling have been implemented for the next RHIC run and will be discussed. This paper aims to describe our understanding of the solder joint cracking issue encountered and present the mitigation measures for future RHIC operation.
Paper: TUPR56
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPR56
About: Received: 15 May 2024 — Revised: 20 May 2024 — Accepted: 20 May 2024 — Issue date: 01 Jul 2024
TUPR62
Investigation of reduced baking time on dynamic pressure in a Taiwan photon source front end system
1575
The Taiwan photon source (TPS), a synchrotron accelerator at the National Synchrotron Radiation Research Center in Taiwan, is a third-generation accelerator operating at 3 GeV that was designed to create a high energy photon source. The TPS front-end (FE) systems are located between the storage ring and beamline, which was designed to protect the safety of users as well as control experimental requirements. As the FE vacuum pressure influences the storage ring and beamline vacuum pressures, the FE vacuum systems must maintain a low dynamic pressure. Therefore, at the beginning of FE system construction, each FE vacuum system is baked at 200°C for 24 hours. Next, when the FE systems need to be upgraded or maintained lead to vacuum interventions, it must also be baked for 24 hours to recover a low dynamic pressure. However, the 24 hour baking process requires manpower support on-site owing to facility safety in the TPS tunnel. The maintenance of the FE systems takes two duty days. Therefore, reducing baking time is necessary in the TPS facility. The beam cleaning efficiency after reduced baking time has been described in this paper.
Paper: TUPR62
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPR62
About: Received: 15 May 2024 — Revised: 23 May 2024 — Accepted: 24 May 2024 — Issue date: 01 Jul 2024
TUPR70
Advanced charge selector for stripped heavy ion beams
1582
A new charge selector is currently under development at FRIB to intercept unwanted charge states of higher-power 17 - 20 MeV/u stripped heavy ion beams. The charge selector is located in the first bending segment of the FRIB linac, where high dispersion separates charge states to allow for their selection. The design concept is based on rotating graphite cylinders that act as an intermediate heat transfer medium, efficiently absorbing beam power and radiating it to a water-cooled heat exchanger. The power in the beam spot of up to 5 kW and the rms spot width as small as 0.7 mm present significant design challenges. Beyond thermal stress, the proposed design addresses the effects of radiation damage and implantation of the intercepted ions. The challenges of the engineering design associated with high temperatures, thermal expansion, rotation and linear actuation feedthrough into vacuum, as well as radiation shielding and remote handling, will be discussed. A comprehensive exploration of these challenges aims to contribute to the broader field of beam interception technology.
Paper: TUPR70
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPR70
About: Received: 15 May 2024 — Revised: 23 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
TUPR78
LHC abort gap monitor electronics upgrade
1600
The LHC Abort Gap Monitor (AGM) is part of the LHC machine protection system (MPS) and is designed to measure the particle population in a 3us wide region known as the "abort gap." This region needs to be kept empty to ensure safe beam dumps. The AGM captures the synchrotron light generated in the visible part of the spectra and converts it into an electric signal. This signal is then processed by an acquisition system and can trigger the ‘abort gap cleaning’ process. The current AGM, which has been in operation since 2010, uses an analogue integrator ASIC and a 40 MHz analogue-to-digital (ADC) converter to provide the particle population information. However, this solution is now considered obsolete and is being replaced by a digital signal processing approach. Working directly in the digital domain not only offers more scalability but also better determinism and reliability. This work presents the new technical solution for the acquisition chain, compares the characteristics of both implementations, and showcases recent measurements conducted on the LHC ion beams.
Paper: TUPR78
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPR78
About: Received: 11 May 2024 — Revised: 21 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
TUPR84
Network status for PAL-XFEL
1611
The accelerator network of the Pohang Accelerator Laboratory (PAL) was initially designed and installed in 2015. It consists of three types of networks: a Public Network for external internet access, an Operation Network for accelerator operation and overall control, and a Control Network for device control and monitoring. From a hardware perspective, it comprises 2 firewalls, 1 intrusion prevention system, 4 backbones, 36 office network switches, and 77 switches for gallery and tunnel networks. Each network is physically or logically separated, and the backbone, serving as the main equipment, is configured in a redundant manner to prepare for failures
Paper: TUPR84
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPR84
About: Received: 02 May 2024 — Revised: 18 May 2024 — Accepted: 18 May 2024 — Issue date: 01 Jul 2024
TUPR85
Identifying downtime sources in CEBAF SRF linac systems for improving its reliability
1614
In this work, we will present some recent analysis of the reliability statistics of the CEBAF SRF linac systems. Based on the data collected by the existing Down Time Manager (DTM), the year-to-year downtime evolution trend of linac zones over the six-year period from FY18 to FY23 is established. An in-depth downtime analysis at a resolution beyond the linac zone level was carried out, by introducing an alternative system hierarchy consisting of the SRF linac sub-systems and components. This new paradigm was implemented in a pilot downtime study over the two-month period of CEBAF operation from 9/13/23 to 11/13/23, enabling localization of the responsible sub-systems (SRF, HPRF, LLRF, Beamline vacuum, Cryogenics, etc.) and hardware components (cavity, tuner, RF coupler, etc.) in the CEBAF SRF linac systems. Pinpointing downtime sources at the sub-systems and component levels holds the key to improving the CEBAF SRF systems reliability. It also helps identify areas of SRF technology development needed by future high-power high-reliability CW SRF linacs.
Paper: TUPR85
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPR85
About: Received: 15 May 2024 — Revised: 20 May 2024 — Accepted: 20 May 2024 — Issue date: 01 Jul 2024
TUPS10
Concluding the operation and development of COSY
1653
The operation of the COler SYnchrotron COSY and its further development ended in October 2023. We briefly review the operation of the accelerator facility and continuous development of its sub-systems. Additionally, this work is put in context of the transformation process that COSY operation and the Institute of Nuclear Physics (IKP) of the Research Center Jülich went through starting 2015. Furthermore, the decommissioning strategy along with the possible further use of COSY components are discussed.
Paper: TUPS10
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPS10
About: Received: 20 May 2024 — Revised: 23 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
TUPS14
Tracking error analysis on the power supply currents of J-PARC main ring main magnets
1665
The bending, quadrupole, and sextupole power supplies in the J-PARC Main Ring (MR) have been upgraded ramping up the average beam power for fast extraction (FX) operation for the neutrino oscillation experiment and slow extraction (SX) operation for the experiments in the hadron facility. The repetition cycles have been shortened from 2.48 sec. to 1.36 sec. for the FX operation and will be soon shortened from 5.2 to 4.24 sec. for the SX operation. The current ripples in the power supply generate the electric current errors of the main magnets. A tracking error can also generate the electric current deviation for the main magnets. A rather large tracking error has been observed after the power supply upgrade. An equivalent circuit analysis for the output load has been conducted to examine the cause. The impact on the beam optics for the longitudinal and transverse beam motions will be discussed. A manipulation of the power supply to improve the tracking errors is tried in the equivalent circuit analysis.
Paper: TUPS14
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPS14
About: Received: 16 May 2024 — Revised: 22 May 2024 — Accepted: 22 May 2024 — Issue date: 01 Jul 2024
TUPS16
An overview of the proton storage ring upgrade at LANSCE
1669
The Los Alamos Neutron Science Center (LANSCE) is one of the oldest operating high-average-power accelerators in the United States, having recently celebrated its 50th anniversary of operation. LANSCE is comprised of an 800-MeV linac capable of concurrently accelerating both H+ and H- ions, and can presently provide beam to six separate user stations. The Proton Storage Ring (PSR) at LANSCE acts as a pulse-stacker, providing intense bunches of protons to the Lujan neutron scattering center target. Critical subsystems have become increasingly difficult to maintain due to spare parts availability; more generally, the PSR contributes significantly to our annual maintenance duration due to beam spill and component activation. The proposed LAMP project would extend the operating lifetime and improve the operational characteristics of the PSR via increasing the physical aperture by 50%; modernizing and improving the performance of the RF buncher system, extraction kickers and impedance inserts; and updating the injection line and stripper foil system for reduced injection losses and improved maintainability. This paper provides an overview of the PSR portion of LAMP.
Paper: TUPS16
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPS16
About: Received: 08 May 2024 — Revised: 20 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
TUPS18
An overview of the LAMP front-end upgrade at LANSCE
1677
The Los Alamos Neutron Science Center (LANSCE) is one of the oldest operating high-average-power accelerators in the United States, having recently celebrated its 50th anniversary of operation. LANSCE is comprised of an 800-MeV linac capable of concurrently accelerating both H+ and H- ions, and can presently provide beam to six separate user stations. The LANSCE accelerator operates with much of its original equipment, including the Cockcroft-Walton injectors and drift-tube linac. As part of the proposed LANSCE Modernization Project (LAMP), a refurbishment and upgrade effort would replace the initial portion of the LANSCE accelerator, from ion sources to the end of the 100-MeV drift-tube linac. This paper describes the overall approach taken to establish performance goals, downselect a preferred technology approach, and identify viable pathways towards implementation.
Paper: TUPS18
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPS18
About: Received: 21 May 2024 — Revised: 22 May 2024 — Accepted: 24 May 2024 — Issue date: 01 Jul 2024
TUPS26
Future directions for RF buncher at LANSCE proton storage ring
1687
Los Alamos Neutron Science Center (LANSCE) is designing a Proton Storage Ring (PSR) refurbishment as part of the proposed LAMP project. An important component of this is the ring RF bunching system at h=1 for one circulating bunch. It has operated with high availability since an upgrade was installed in 1999 to raise the gap voltage*. A second RF system at h=2 is planned to improve the bunching factor, reducing the peak beam current at the center of the bunch resulting from space charge forces, helping mitigate effects of electron cloud and leaving an avenue for circulating two bunches in the future. The unique low output impedance RF system for h=1 is based on a cathode follower configuration using push-pull triode vacuum tubes. This feature provides automatic beam loading compensation without active feedback or feedforward systems. The triodes are no longer produced, and suitable replacements are unavailable. The ferrite rings of the h=1 system are also obsolete. Our goals include determining a suitable replacement amplifier configuration that can work on either frequency, and developing a replacement resonator for each harmonic that uses current production ferrite material.
Paper: TUPS26
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPS26
About: Received: 15 May 2024 — Revised: 22 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
TUPS27
Progress towards the completion of the proton power upgrade project
1691
The Proton Power Upgrade project at the Spallation Neutron Source at Oak Ridge National Laboratory will increase the proton beam power capability from 1.4 to 2.8 MW. Upon completion in early 2025, 2 MW of beam power will be available for neutron production at the existing first target station (FTS) with the remaining beam power available for the future second target station (STS). The project has installed seven superconducting radio-frequency (RF) cryomodules and supporting RF power systems to increase the beam energy by 30% to 1.3 GeV, and the beam current will be increased by 50%. The injection and extraction region of the accumulator ring are being upgraded, and a new 2 MW mercury target has been developed along with supporting equipment for high-flow gas injection to mitigate cavitation and fatigue stress. The first four cryomodules and supporting systems were commissioned in 2022-2023 and supported neutron production at 1.05 GeV, 1.7 MW with high reliability. The first-article 2 MW target was operated successfully for approximately 4400 MW-Hours over two run periods. The long outage began in August 2023 for installation of the remaining technical equipment and construction of the Ring-to-Target Beam Transport tunnel stub that will enable connection to the STS without interrupting operation of the FTS. The upgrade is proceeding on-schedule and on-budget, and resumption of neutron production for the user program is planned for July 2024.
Paper: TUPS27
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPS27
About: Received: 30 Apr 2024 — Revised: 20 May 2024 — Accepted: 20 May 2024 — Issue date: 01 Jul 2024
TUPS30
Simulation study on an electron cloud and plasma waves confined in GL2000 device
1702
GL2000 Gabor-lens (GL)[1, 2] is a 2-m long device constructed and successfully operated at Goethe University. The confined electron column is much longer compared to previous constructed lenses and offers unique opportunity for investigation of electron cloud dynamics. Especially, kind of fingertip stopband structures were precisely measured in production diagram (operation function) in the year 2023 [2]. This fully reproducible behavior and dependence on a rest gas pressure left unexplained. For this purpose, a large scale multi-particles simulation PIC(particle-in-cell)-code was written in C++ and implemented on FUCHS-Cluster of the Goethe University. The main objective is to find an optimal operation parameter set for a stable operation of GLs, which is crucial for high energy hadron beam transport and focusing. Further topic will be investigation of possible longitudinal handling of bunched ion beams. The first simulation result will be presented and discussed.
Paper: TUPS30
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPS30
About: Received: 15 May 2024 — Revised: 20 May 2024 — Accepted: 24 May 2024 — Issue date: 01 Jul 2024
TUPS31
Intensity reach in the CERN PSB with the high-current LINAC4 source
1706
The CERN Proton Synchrotron Booster (PSB) was upgraded within the LHC Injectors Upgrade (LIU) project and delivers a large variety of high-intensity beams for fixed target experiments and high-brightness beams for collisions at the LHC. In the context of the Physics Beyond Colliders (PBC) study and of a possible upgrade of the ISOLDE experimental area, intensities up to 1500×1e+10 particles per ring are considered. High-intensity tests have thus been performed during machine development studies in 2023 injecting the nominal or higher beam current from Linac4. In this contribution, the intensity reach and the main performance limitations for the production of high-intensity beams in the PSB are presented. The results are compared to numerical simulations.
Paper: TUPS31
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPS31
About: Received: 13 May 2024 — Revised: 20 May 2024 — Accepted: 20 May 2024 — Issue date: 01 Jul 2024
TUPS34
Superconducting magnet string test for the SIS100 accelerator of FAIR
1718
The SIS100 accelerator, currently under construction in Darmstadt (Germany), consists of six arc and straight sections. Each of the six cryogenic arc sections comprises fourteen regularly repeating optical cells (lattice). Each standard cell includes two dipole magnets and two quadrupole units integrated in a quadrupole doublet module. The SIS100 String Test technically represents one standard cell of the arc section of the SIS100, terminated by and End Cap and a Bypass Line as a representation of the end of the arc section. The purpose of the SIS100 String Test is to validate all technical systems such as cryogenics, vacuum, interlock and quench detection and investigate their collective behavior. A wide spectrum of tests will be performed during cool down, powering at operational conditions and warm up. Additionally, the experience gained during the SIS100 String Test will be crucial for the installation, commissioning and operation of the SIS100. The planning, installation process and first experimental results of the String Test will be presented.
Paper: TUPS34
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPS34
About: Received: 15 May 2024 — Revised: 21 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
TUPS37
Shower simulations for the CERN proton synchrotron internal dump and possible shielding options
1730
During the Long Shutdown 2, the two internal dumps were replaced and successfully integrated into the CERN Proton Synchrotron operation to withstand the intense and bright beams for the High-Luminosity LHC. They function as safety devices, designed to swiftly intersect the beam’s trajectory and effectively stop the beam over multiple turns. A significant challenge arises from their limited energy absorption capacity. Previous studies indicate that at the maximum PS beam energy of 26 GeV, only about 7% of the energy is absorbed by the dumps upon their insertion. This study, employing a combination of the FLUKA and SixTrack simulation code chain, evaluates the absorbed dose in downstream elements in view of the projected increase of beam intensities, according to the LHC injector upgrade parameters, and explores the feasibility and potential benefits of implementing shielding as a mitigation measure.
Paper: TUPS37
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPS37
About: Received: 15 May 2024 — Revised: 17 May 2024 — Accepted: 17 May 2024 — Issue date: 01 Jul 2024
TUPS39
Benchmarking power deposition from fast losses of heavy-ion beams at the onset of LHC Run 3
1738
In 2023, the LHC started its Run 3 operation with 208Pb82+ beams at 6.8 ZTeV, with a substantially higher number of bunches compared to past runs. Several new hardware systems were used operationally for the first time with high-intensity beams, including bent crystal collimators in the betatron cleaning insertion. Crystal-assisted collimation reduces the leakage of secondary ion fragments to the downstream dispersion suppressors, therefore decreasing the risk of quenching superconducting magnets. Nevertheless, one of the limitations encountered during the 2023 run were events with fast beam losses impacting the collimation system, which triggered multiple premature beam aborts on Beam Loss Monitors (BLMs). In this contribution, we present energy deposition simulations for these events, performed with the FLUKA tool, aiming to quantify the quench margin for the fast loss regime (~30 ms). To assess the predictive ability of the model, benchmarks against 2023 measurements are presented. The studies provide an important input for fine-tuning BLM thresholds in future heavy-ion runs, therefore increasing the tolerance to beam losses and hence the LHC availability.
Paper: TUPS39
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPS39
About: Received: 15 May 2024 — Revised: 19 May 2024 — Accepted: 19 May 2024 — Issue date: 01 Jul 2024
TUPS40
A novel two stage collimation unit for Fermilab booster
1742
A new two-stage collimation unit (2SC) for Fermilab Booster will be installed during 2024 summer shutdown. It is a supplementary collimator for existing single stage Booster collimators. Unique operational principles of this new 2SC adapted to Booster conditions are described. Results of beam dynamics simulations on collimation efficiency of the new 2SC are presented. Evaluation of collimator shielding has been performed with MARS code. The analysis on prompt and residual activation was found to meet Fermilab Radiological Control limits. We will also present the results from analysis on shielding as well as residual activation.
Paper: TUPS40
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPS40
About: Received: 15 May 2024 — Revised: 18 May 2024 — Accepted: 18 May 2024 — Issue date: 01 Jul 2024
TUPS41
Crystal collimation for the HL-LHC upgrade using MERLIN++ accelerator physics library
1746
This paper details the implementation and benchmarking of crystal collimation within MERLIN++ accelerator physics library and demonstrates its application in simulating crystal collimation process for the High Luminosity upgrade of LHC at CERN. Crystal collimation is one of the key technologies suggested to enhance the current collimation system according to the requirements of HL-LHC upgrade due to its increased beam energy and luminosity. This paper outlines the proposed methodology for this study which includes implementing the demonstrated physics of particle crystal interaction in MERLIN++, benchmarking it with the existing experimental data for simulating the HL-LHC operational scenarios with the crystals as primary collimators. MERLIN++ has already been efficiently used for multiple LHC collimation studies which highlights its importance , making it an essential simulation tool for comparative analysis with other simulation tools, as relying on a single tool for concluding the HL-LHC collimation system is often insufficient. As collimation systems are fundamental for machine protection , accurately predicting the crystal collimation performance is of utmost importance to know how they will perform in HL-LHC to guarantee that the HL-LHC meets its intended objectives with crystal collimators.
Paper: TUPS41
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPS41
About: Received: 15 May 2024 — Revised: 18 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
TUPS42
Real time crystal collimation monitoring at the CERN Large Hadron Collider
1750
At the CERN Large Hadron Collider (LHC), bent crystals play a crucial role in efficiently redirecting beam halo particles toward secondary collimators used for absorption. This innovative crystal collimation method leverages millimeter-sized crystals to achieve deflection equivalent to a magnetic field of hundreds of Tesla, significantly enhancing the machine’s cleaning performance particularly when running with heavy ion beams. Nevertheless, ensuring the continuous effectiveness of this process requires the optimal channeling angle with respect to the beam to be constantly maintained. The primary goal of this study is to improve the monitoring of crystal collimation by providing a tool that detects any deviations from the optimal channeling orientation. These deviations can arise from both crystal movement and fluctuations in beam dynamics. The ability to adapt and compensate for these changes is crucial for ensuring stable performance of crystal collimation during LHC operation. To achieve this, a feedforward neural network (FNN) was trained using data collected during the 2023 lead ion physics run at the LHC. The results demonstrate the network’s capability to supervise these crystal devices, accurately classifying when the crystal is optimally aligned with respect to the circulating beam. Furthermore, the model provides valuable insights into how to adjust the crystal’s position to restore optimal channeling conditions when required.
Paper: TUPS42
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPS42
About: Received: 10 May 2024 — Revised: 19 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
TUPS43
Optimization of a welding procedure for making critical aluminum welds on the LBNF absorber core block
1754
The LBNF Absorber consists of thirteen 6061-T6 aluminum core blocks. The core blocks are water cooled with de-ionized (DI) water which becomes radioactive during beam operations. The cooling water flows through gun-drilled channels in the core blocks. A weld quality optimization was performed to produce National Aeronautical Standard (NAS) 1514 Class I [1] quality welds on the aluminum core blocks. This was not successful in all cases. An existing Gas Tungsten Arc Welding (GTAW) Welding Procedure Specification (WPS) was fine tuned to minimize, in most cases, and eliminate detectable tungsten inclusions in the welds. All the weld coupons, how-ever passed welding inspection as per the piping code: ASME B31.3 Normal Fluid Service [2]. Tungsten electrode diameter, type, and manufacturer were varied. Some of the samples were pre-heated and others were not. It was observed that larger diameter electrodes, 5/32 in., with pre-heated joints resulted in welds with the least number of tungsten inclusions. It is hypothesized that thinner electrodes breakdown easily and get lodged into the weld pool during the welding process. This breakdown is further enhanced by the large temperature differential be-tween the un-preheated sample and the hot electrode.
Paper: TUPS43
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPS43
About: Received: 30 Apr 2024 — Revised: 22 May 2024 — Accepted: 22 May 2024 — Issue date: 01 Jul 2024
TUPS44
Multiphysics simulations of thermal shock testing of nanofibrous high power targets
1758
Increase of primary beam power for neutrino beam-lines leads to a reduced lifespan for production targets. New concepts for robust targets are emerging from the field of High Power Targetry (HPT); one idea being investigated by the HPT R&D Group at Fermilab is an electrospun nanofiber target. As part of their evaluation, samples with different densities were sent to the HiRadMat facility at CERN for thermal shock tests. The samples with the higher density, irradiated under a high intensity beam pulse, exhibit major damage at the impact site whereas those with the lower density show no apparent damage. The exact cause of this failure was unclear at the time. In this paper, we present the results of multiphysics simulations of the thermal shock experienced by the nanofiber targets that suggest the failure originates from the reduced permeability of the high density sample to air flow. The air present in the porous target expands due to heating from the beam, but is unable to flow freely in the high density sample, resulting in a larger back pressure that blows apart the nanofiber mat. We close with a discussion on how to further validate this hypothesis.
Paper: TUPS44
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPS44
About: Received: 15 May 2024 — Revised: 19 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
TUPS47
Measurements of hysteretic effects and eddy currents on a FeCo magnet for the design of a novel ion gantry
1766
Hadron therapy uses scanning magnets to precisely deliver therapeutic beams, minimizing the damage to healthy tissues and reducing side effects. A collaboration between CNAO, CERN, INFN and MedAustron is developing an innovative gantry design with superconducting magnets and a downstream scanning system. The project features two compact scanning dipoles, each with a central field of 1 T – about three times higher than current magnets used in clinical practice. The heightened magnetic field, together with the large rate of varying currents required for operation during treatments, prompts an investigation into non-linearities, necessitating a careful study of their impact on the performances of the system. This contribution provides insights into the dynamic behavior of a prototype scanning magnet with a FeCo yoke, with measurements of saturation, hysteretic effects, and eddy currents performed at Frascati National Laboratories, elucidating the feasibility of the proposed model. Additionally, in view of clinical implementation, the study explores methods of fast degaussing.
Paper: TUPS47
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPS47
About: Received: 15 May 2024 — Revised: 17 May 2024 — Accepted: 18 May 2024 — Issue date: 01 Jul 2024
TUPS54
Bayesian optimization for beam centroid correction at ISAC
1786
Beam tuning in a post-accelerator facility such as TRIUMF’s ISAC involves a considerable amount of overhead and often leads to tunes which diverge from the theoretical optimum for the system, introducing undesirable effects such as aberrations or chromatic couplings. Bayesian Optimization for Ion Steering (BOIS) has been developed and tested to perform centroid corrective steering, after the transverse optics have been set to theory, in a method which is fully online and easy to deploy. Naïve multi-objective adaptations, scaleBOIS and boundBOIS have been introduced to perform corrective transverse steering with minimal transverse fields . Tests in the low-energy electrostatic transport beamlines at ISAC I performed comparably to human operators. This work holds promise for enhancing the efficiency and reliability of beam delivery via autonomous tuning methods, supporting TRIUMF's scientific mission.
Paper: TUPS54
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPS54
About: Received: 15 May 2024 — Revised: 20 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
TUPS56
Machine learning-based extraction of longitudinal beam parameters in the LHC
1794
Accurate knowledge of beam parameters is essential for optimizing the performance of particle accelerators like the Large Hadron Collider (LHC). An initial machine-learning (ML) model for the reconstruction of the longitudinal distribution has been extended to extract the main parameters of multiple bunches at LHC injection. The extended model utilizes an encoder-decoder architecture to analyze sets of longitudinal profile measurements. Its development was partially driven by the need of a real-time beam energy error estimate, which was not directly available in the past. The derived beam parameters moreover include injection phase error, bunch length and intensity in the LHC, as well as the RF voltages at extraction from the Super Proton Synchrotron (SPS) and at capture in the LHC. In this paper, we compare the results of the ML model with conventional measurements of bunch length and energy error, from the beam quality monitor (BQM) and the orbit acquisition system, respectively. These benchmarks demonstrate the potential of applying the ML model for operational exploitation in LHC.
Paper: TUPS56
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPS56
About: Received: 10 May 2024 — Revised: 22 May 2024 — Accepted: 22 May 2024 — Issue date: 01 Jul 2024
TUPS57
Machine learning enabled model predictive control of the FRIB RFQ
1798
Efficient control of frequency detuning for the radio-frequency quadrupole (RFQ) at the Facility for Rare Isotope Beams (FRIB) is still challenging. The transport delay and the complicated heat transfer process in the cooling water control system convolute the control problem. In this work, a long-short term memory (LSTM)-based Koopman model is proposed to deal with this time-delayed control problem. By learning the time-delayed correlations hidden in the historical data, this model can predict the behavior of RFQ frequency detuning with given control actions. With this model, a model predictive control (MPC) strategy is developed to pursue better control performance.
Paper: TUPS57
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPS57
About: Received: 13 May 2024 — Revised: 17 May 2024 — Accepted: 17 May 2024 — Issue date: 01 Jul 2024
TUPS63
Overview of machine learning based beam size control during user operation at the Advanced Light Source
1816
The Advanced Light Source (ALS) storage ring employs various feedback and feedforward systems to stabilize the circulating electron beam thus ensuring delivery of steady synchrotron radiation to the users. In particular, active correction is essential to compensate for the significant perturbations to the transverse beam size induced by user-controlled tuning of the insertion devices, which occurs continuously during normal operation. Past work at the ALS already offered a proof-of-principle demonstration that Machine Learning (ML) methods could be used successfully for this purpose. Recent work has led to the development of a more robust ML-algorithm capable of continuous retraining and its routine deployment into day-to-day machine operation. In this contribution we focus on technical aspects of gathering the training data and model analysis based on archived data from 2 years of user operation as well as on the model implementation including the interface of an EPICS Input/Output Controller (IOC) into a Phoebus Panel, enabling operator-level supervision of the Beam Size Control (BSC) tool during regular user operation.
Paper: TUPS63
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPS63
About: Received: 17 May 2024 — Revised: 17 May 2024 — Accepted: 17 May 2024 — Issue date: 01 Jul 2024
TUPS68
SRF cavity fault prediction using deep learning at Jefferson Lab
1831
In this study, we present a deep learning-based pipeline for predicting superconducting radio-frequency (SRF) cavity faults in the Continuous Electron Beam Accelerator Facility (CEBAF) at Jefferson Lab. We leverage pre-fault RF signals from C100-type cavities and employ deep learning to predict faults in advance of their onset. We train a binary classifier model to distinguish between stable and impending fault signals, where each cryomodule has a uniquely trained model. Test results show accuracies exceeding 99% in each of the six models for distinguishing between normal signals and pre-fault signals from a class of more slowly developing fault types, such as microphonics-induced faults. We describe results from a proof-of-principle demonstration on a realistic, imbalanced data set and report performance metrics. Encouraging results suggest that future SRF systems could leverage this framework and implement measures to mitigate the onset in more slowly developing fault types.
Paper: TUPS68
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPS68
About: Received: 02 May 2024 — Revised: 18 May 2024 — Accepted: 18 May 2024 — Issue date: 01 Jul 2024
TUPS69
SRF cavity instability detection with machine learning at CEBAF
1835
During the operation of the Continuous Electron Beam Accelerator Facility (CEBAF), one or more unstable superconducting radio-frequency (SRF) cavities often cause beam loss trips while the unstable cavities themselves do not necessarily trip off. The present RF controls for the legacy cavities report at only 1 Hz, which is too slow to detect fast transient instabilities during these trip events. These challenges make the identification of an unstable cavity out of the hundreds installed at CEBAF a difficult and time-consuming task. To tackle these issues, a fast data acquisition system (DAQ) for the legacy SRF cavities has been developed, which records the sample at 5 kHz. A Principal Component Analysis (PCA) approach is being developed to identify anomalous SRF cavity behavior. We will discuss the present status of the DAQ system and PCA model, along with initial performance metrics. Overall, our method offers a practical solution for identifying unstable SRF cavities, contributing to increased beam availability and facility reliability.
Paper: TUPS69
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPS69
About: Received: 13 May 2024 — Revised: 16 May 2024 — Accepted: 18 May 2024 — Issue date: 01 Jul 2024
TUPS70
The Data Platform: an independent system for management of heterogeneous, time-series data to enable data science applications
1839
The Data Platform is a fully independent system for management and retrieval of heterogeneous, time-series data required for machine learning and general data science applications deployed at large particle accelerator facilities. It is an independent subsystem within the larger Machine Learning Data Platform (MLDP) which provides full-stack support for such facilities and applications [1]. The Data Platform maintains the heterogeneous data archive along with all associated metadata and post-acquisition user annotations. It also facilitates all interactions between data scientists and the data archive, thus it directly supports all back-end data science use cases. Accelerator facilities include thousands of data sources sampled at high frequencies, so ingestion performance is a key requirement and the current challenge. We describe the operation, architecture, performance, and development status of the Data Platform.
Paper: TUPS70
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPS70
About: Received: 15 May 2024 — Revised: 16 May 2024 — Accepted: 18 May 2024 — Issue date: 01 Jul 2024
TUPS72
Progress on combining digital twins and machine learning-based control for accelerators at SLAC
1846
Advances in high-performance computing have enabled detailed physics simulations, including those with nonlinear collective effects such as space charge, to be deployed online in a control room setting to aid operator intuition and be used directly in automatic tuning. Simultaneously, machine learning (ML) has enabled deployment of detailed models online with sub-second execution time, opened up new avenues for adapting simulation models to more closely match real accelerator behavior, and enabled novel ways to combine detailed physics simulations and ML-based tuning. This contribution will provide an overview of how these tools are being developed and successfully applied at SLAC, with an emphasis on experimental demonstrations. This includes improvements in adaptive calibration methods, novel approaches to simulation (e.g. differentiable physics combined with ML), and the use of system models in ML-based tuning (e.g. Bayesian optimization with system model priors, iterative simulation and ML tuning to aid LCLS-II injector commissioning). Discussion of the software infrastructure required to achieve this and deploy these solutions into regular operation will also be discussed.
Paper: TUPS72
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPS72
About: Received: 22 May 2024 — Revised: 03 Jun 2024 — Accepted: 03 Jun 2024 — Issue date: 01 Jul 2024
TUPS76
Machine learning for data analysis and control of an MeV ultrafast electron diffraction system and a photocathode laser and gun system: updates
1858
An MeV ultrafast electron diffraction (MUED) in-strument system is a unique characterization technique used to study ultrafast processes in a variety of mate-rials by a pump-probe method. Combining this tech-nology with rapid data science and artificial intelli-gence/machine learning (AI/ML) technologies in con-junction with high-performance computing can create a turnkey, automated instrument. AI-based system controls can also provide real-time electron beam optimization or provide virtual diagnostics of the beamline operational parameters. Deep learning can be applied to the MUED diffraction patterns to recover valuable information on subtle lattice variations Such a data-science-enabled MUED facility will open this technique to a wider user base with a wider variation of experience, providing an automated or semi-automated state-of-the-art instrument, with a beamline scientist orchestrating the overall data collection pro-cess. Updates on research and development efforts pri-marily in the realm of initial studies of network con-nection between the ALCF and the Accelerator Test Facility (ATF) at Brookhaven National Laboratory are presented.
Paper: TUPS76
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPS76
About: Received: 15 May 2024 — Revised: 23 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
TUPS85
Recent progress in laser wire-based H⁻ beam diagnostics at the SNS linac
1873
Laser wire has been used for nonintrusive profile and emittance measurements of operational hydrogen ion (H-) beam at the SNS linac. In this talk, we will describe the following recent developments in the laser wire system. 1) An upgraded light source and laser transport line which enables novel measurement capabilities including longitudinal profile measurement and high-energy proton beam extraction over potentially an entire macropulse. 2) A dual-detector emittance measurement scheme that boosted the dynamic range by an order of magnitude. 3) Design and implementation laser-wire-based nonintrusive longitudinal phase space measurement system.
Paper: TUPS85
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-TUPS85
About: Received: 17 May 2024 — Revised: 20 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
WEXN1
Superconducting magnets technology for a European heavy ion gantry
1880
Various initiatives in Europe have been launched to study superconducting magnets for a rotatable gantry suitable to deliver up to 430 MeV/u carbon ions for hadron therapy. Different technologies and layouts are being considered: the baseline solution is developed within the EuroSIG collaboration and consists of a strongly curved cos-$\theta$ dipole based on the classical NbTi superconductor. The HITRIplus and I.FAST projects are dedicated to the study of the novel Canted Cosine Theta (CCT) dipoles based on NbTi and also HTS. Common design targets were set to allow a direct comparison of the different solutions: 4 T central field in an 80 mm bore, a curvature radius of 1.65 m, and a ramp rate of 0.15 – 0.4 T/s. The progress in the construction of four different demonstrator magnets is discussed and a preliminary comparison is proposed.
Paper: WEXN1
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEXN1
About: Received: 20 May 2024 — Revised: 23 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
WEAD3
Echo-enabled harmonic generation at FERMI FEL-1: commissioning and initial user experience
1889
The FERMI free-electron laser (FEL) facility has recently achieved a significant milestone with the successful implementation of the echo-enabled harmonic generation (EEHG) scheme in the FEL-1 amplifier line. This advancement is part of a broader upgrade strategy aiming at expanding the covered spectral range of the facility to the entire water window and beyond. Through this upgrade, the maximum photon energy of FEL-1 has been doubled and spectral quality has been enhanced. The updated FERMI FEL-1 is the first user facility operating in the spectral range 20-10 nm utilizing the EEHG scheme. It will serve also as the ideal test bench for conducting new machine studies in the perspective of future developments. In this contribution, we present the results obtained during the commissioning phase and the first user experiments.
Paper: WEAD3
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEAD3
About: Received: 15 May 2024 — Revised: 20 May 2024 — Accepted: 20 May 2024 — Issue date: 01 Jul 2024
WEYD1
Status and outlook on slow extraction operation at J-PARC main ring
1905
The Main Ring (MR) at J-PARC (Japan Proton Accelerator Research Complex) is a proton synchrotron that accelerates protons from 3 GeV to 30 GeV. One of the two MR's extraction modes is slow extraction using third-order resonance toward the Hadron Experimental Facility, where various particle and nuclear physics experiments are conducted. There are two major points in the slow extraction: beam loss reduction and flat spill structure of the extracted beam. In the beam operation of 2021, we achieved a beam power of 65 kW with a high extraction efficiency of 99.5% and a spill duty factor of 60%, but requirements for further improvements from physics experiments have never stopped. From 2021 to 2022, various devices in the MR were upgraded. The primary purpose of this upgrade was to increase the beam power by shortening the acceleration time and increasing the repetition rate. To achieve this goal, we rebuilt most parts of the main magnet power supplies. The new power supplies are also expected to be significantly improved in the current ripple. Thus the time structure of the slow extracted beam is also expected to be greatly improved. In addition, plans are underway for further reduction of the beam loss through the use of beam diffusers and bent silicon crystals and for improvement of the spill structure by feedback algorithms reconstruction. This talk presents the status of the MR and the prospects of the slow extraction after the MR upgrade.
Paper: WEYD1
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEYD1
About: Received: 20 May 2024 — Revised: 21 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
WEBN3
Availability and luminosity in the Future Circular Electron-Positron Collider (FCC-ee)
1915
The Future Circular Electron-Positron Collider (FCC-ee) is CERN's leading proposal for the next generation of energy-frontier particle accelerators. To reach integrated luminosity goals, it aims to be operational for minimum 80 % of the scheduled 185 physics days each year. For comparison, the Large Hadron Collider (LHC) achieved 77 % in 2016-2018. There are additional challenges in the FCC-ee due to its size, complexity and ambitious technical objectives. Availability is therefore a significant risk to physics deliverables. This paper presents the framework used to analyse availability and luminosity in the FCC-ee. To showcase its capabilities, first, a top-level system deconstruction reveals several key relationships for the Radio Frequency (RF) system. Second, two proposed technologies are simulated to overcome constraints in the Z, W operation cycle. Of these, pre-polarised bunch injection (PPBI) shows tremendous advantage for shielding integrated luminosity from a challenging availability environment.
Paper: WEBN3
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEBN3
About: Received: 14 May 2024 — Revised: 19 May 2024 — Accepted: 19 May 2024 — Issue date: 01 Jul 2024
WEZD1
Status of SuperKEKB and experience with nonlinear collimation
1923
An update on SuperKEKB status will be presented including an overview of performance limitations and experience with nonlinear collimation.
Paper: WEZD1
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEZD1
About: Received: 15 May 2024 — Revised: 17 May 2024 — Accepted: 18 May 2024 — Issue date: 01 Jul 2024
WEZD2
The electron cloud and its impact on LHC and future colliders
1928
The secondary emission of electrons and their interaction with the electromagnetic fields of charged particle beams can lead to the build-up of electron clouds in accelerator beam chambers. The interaction of the electrons with both the beam and the chamber walls leads to detrimental effects, such as transverse instabilities and emittance growth, beam loss, pressure rise and heat load. Such effects are systematically observed in the Large Hadron Collider (LHC) during operation with proton beams with the nominal bunch spacing of 25 ns. Furthermore, the severity of electron cloud effects has increased after each long shutdown period of the machine, due to a degradation of the beam screen surfaces with air-exposure. Consequently, electron cloud is already limiting the total intensity in the collider and is one of the main concerns for the performance of the HL-LHC upgrade. In this contribution, the present understanding of electron cloud in hadron accelerators is reviewed. Measurements and observations at the LHC are presented, the impact on performance is evaluated and mitigation measures are discussed along with lessons for future machines.
Paper: WEZD2
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEZD2
About: Received: 15 May 2024 — Revised: 16 May 2024 — Accepted: 16 May 2024 — Issue date: 01 Jul 2024
WECD1
FCC-ee large-scale project installation planning: challenges & proposals
1934
CERN is contemplating further advancements in the energy frontier through the Future Circular Collider (FCC) study, envisioning a 90.7 km underground accelerator with multiple energy stages over time. Following the European Strategy for Particle Physics recommendation in 2020, CERN initiated a feasibility study to scrutinize all aspects of the FCC project. A crucial component of this study involves developing a timeline from project approval to the beam operation of FCC-ee, the first collider with electron and positron. Since the last planning iteration in 2018, modifications in the machine layout and shaft configuration necessitated a re-evaluation of the planning. This paper focuses on the updated planning for FCC-ee, spanning from civil engineering completion to beam operation. It compiles pertinent elements, including the civil engineering release date, layout data, and human resources regulations and limitations. These elements were analyzed systematically to derive a sector sequence. Employing a bottom-up approach in conjunction with resource constraints, an overarching plan for the FCC-ee machine until the start of operations was formulated.
Paper: WECD1
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WECD1
About: Received: 15 May 2024 — Revised: 20 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
WECN3
The testing experience of the cryomodules for the ESS beam on target phase at 2 MW capability
1949
ESS is completing the installation of the first phase of operation, which will start in fall 2024 on the partial beam dump and proceed with operation on the target in 2025, after receiving the intentional neutron production license from the authorities. All modules for this operation phase, with an energy reach of 870 MeV and a power capability of 2 MW, will be tested by spring 2024. The CM performance, associated statistics and the resulting linac composition is discussed here. Testing activities for the remaining CM for the full ESS 5 MW scope will continue until mid 2026.
Paper: WECN3
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WECN3
About: Received: 16 May 2024 — Revised: 20 May 2024 — Accepted: 20 May 2024 — Issue date: 01 Jul 2024
WEPC05
Quantitative description and correction of longitudinal drifts in the Fermilab linac
1964
The Fermilab Linac accepts the 0.75 MeV H- ions from the front end and accelerates them to 400 MeV for injection into the Booster. Day-to-day drifts of the longitudinal trajectory in the Linac, reconstructed from phase readings of Beam Position Monitors, are at the level of several degrees. They are believed to cause additional losses both in the Linac and Booster, and are addressed by empirically adjusting the phases of Linac cavities. This work explores the option of expressing these drifts in terms of phase shifts in two cavities at the low-energy part of the Linac. Such description allows for a simplified visual representation of the drifts, suggest a clear algorithm for their compensation, and provides a tool for estimating efficiency of such compensation.
Paper: WEPC05
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPC05
About: Received: 22 May 2024 — Revised: 23 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
WEPC13
Status of the RUEDI UK national facility design
1979
RUEDI (Relativistic Ultrafast Electron Diffraction & Imaging) is a proposed facility which will deliver single-shot, time-resolved, imaging with MeV electrons, and ultrafast electron diffraction down to 10 fs timescales. RUEDI is being designed to enable the following science themes: dynamics of chemical change; materials in extreme conditions; quantum materials; energy generation, storage, and conversion; and in vivo biosciences. RUEDI is proposed to be built at STFC’s Daresbury Laboratory in the UK.
Paper: WEPC13
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPC13
About: Received: 15 May 2024 — Revised: 23 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
WEPC14
A new rf design of the two-mode transverse deflecting structure
1983
SSRF (Shanghai Synchrotron Radiation Facili-ty)/SXFEL (Shanghai Soft X-ray FEL) Facility has de-veloped an advanced variable polarization transverse deflecting structure TTDS (two-mode transverse deflect-ing structure) to perform variable polarization based on the design of a dual-mode RF structure. The 15-cell prototype of the TTDS was fabricated at SSRF/SXFEL. Because the two modes operate in the same structure, any geometric change will affect both modes. A new RF design of the regular cell is proposed to improve rf per-formance. The two modes are coupled independently in two pairs of side coupling holes. The work presented in this paper is focused on the new design and the rf param-eters compared with the initial design.
Paper: WEPC14
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPC14
About: Received: 15 May 2024 — Revised: 24 May 2024 — Accepted: 24 May 2024 — Issue date: 01 Jul 2024
WEPC17
Design of a Ku-band side-coupled standing wave 2.5 MeV accelerator
1993
Compact accelerator systems are assuming an increasingly significant role within the domain of radiotherapy. As processing technology continues to mature, X-band accelerators have garnered extensive utilization. This study introduces a design for a side-coupled traveling-wave Ku-band accelerator tube, leveraging established processing methodologies. The envisaged particle output energy stands at 2.5 MeV, with a microwave power source requiring a 300 kW input sourced from a klystron. The microwave design outcomes, derived using ANSYS HFSS, are delineated herein, alongside considerations pertaining to dynamic output and engineering design. Subsequent stages will subject this accelerator tube to processing tests, with the overarching objective of effectively supplanting the natural radiation source Co60 within the realm of radiotherapy.
Paper: WEPC17
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPC17
About: Received: 14 May 2024 — Revised: 23 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
WEPC21
Mass production of 3.9 GHz 9-cell cavities at SHINE
2006
Two 3.9~GHz cryomodules of sixteen cavities are required in the Shanghai high-repetition-rate XFEL and extreme light facility (SHINE) linac. They are placed before the first bunch compressor to linearize energy distribution. A total of twenty-one 3.9~GHz 9-cell cavities including two prototypes were fabricated and tested. The first two prototypes reached a Q0 of 2.9x10^9 at 13.1 MV/m and a maximum accelerating gradient of 20.0 MV/m during the vertical test, with a large margin with respect to the SHINE specification. The first prototype was integrated into a small cryostat and horizontal tested. Batch fabrication of nineteen cavities started after the prototype qualification. The 3.9 GHz cryomodules are under assembling after the vertical tests. Horizontal tests are planned to start from mid of 2024. This paper will introduce the experience of the prototype development and mass production of the 3.9 GHz cavities.
Paper: WEPC21
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPC21
About: Received: 15 May 2024 — Revised: 24 May 2024 — Accepted: 24 May 2024 — Issue date: 01 Jul 2024
WEPC22
Recent studies on high current operation at the compact ERL
2010
The compact ERL (cERL) is operated at mid-energy region around 17 MeV for beam studies on industrial applications since 2017. Toward the future high power FEL source for EUV lithography, high current beam operation was demonstrated at low bunch charge after install of undulators as a first step. It is critical to reduce beam loss not to exceed 20 uSv/h outside the shield wall of the cERL acceleration room, however, it can increase especially at the arc sections, the undulators, and superconducting cavities for decelerating. Therefore, 16 high-speed loss monitors are located along the whole beam line as the machine protection system. Recently, machine learning is applied for beam tuning to reduce all loss monitor signal. In addition, we tried the energy recovery operation while undulator light is amplified at a high bunch charge around 60 pC.
Paper: WEPC22
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPC22
About: Received: 13 May 2024 — Revised: 22 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
WEPC26
APS storage ring waveguide layout study for solid state amplifier upgrade
2026
Currently, radiofrequency (RF) power to the Argonne Advanced Photon Source (APS) storage ring and Booster cavities is provided by several klystrons. APS is in the process of replacing the storage ring klystrons with clusters of 160 kW solid state amplifier (SSA) gradually. It is required to keep most of the existing equipment racks, klystrons and cable trays for smooth operation and transition until the SSA upgrade commissioning. The replaced klystrons may be kept for future RF power backup to the sectors waiting for SSA upgrade. The following post challenges to the waveguide installation: confined space of the waveguide lines removal and installation, finding space for additional new equipment racks, SSA racks, power combiners, AC power distribution, water cooling systems and new cable trays. The goal of this study is to generate a new waveguide layout design with enough space clearance for installation, operation, repairing of SSA plus AC distribution, water cooling system and all safety requirements. This work presents the study of waveguide lines layout modification for storage ring cavities and the result of this study will be a guideline of waveguide construction for APS storage ring SSA upgrade as well as the installation of the system. A discussion of waveguide combiner vs. coax combiner is also presented.
Paper: WEPC26
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPC26
About: Received: 14 May 2024 — Revised: 17 May 2024 — Accepted: 17 May 2024 — Issue date: 01 Jul 2024
WEPC31
Towards Elettra 2.0 - R&I preparation activities
2033
The “Dark Period” (DP), that is the final shutdown for the Elettra Storage Ring (SR) with its ancillary equipment and most of its beamlines, is scheduled to start on July 2nd, 2025. During the DP we will remove the complete SR lattice structure with annexed cabling, piping, and supports; the Service Area, where most of the equipment to operate the SR is installed, will be completely renovated; the majority of the photon beamlines will be removed, moved, updated or “brand-new” installed, causing the reconfiguration of a large part of the outer wall of the SR tunnel. Several activities are running in order to reduce the Removal and Installation (R&I) workload – already quite significant – during the DP. These activities are mostly related to the beamlines in the Experimental Hall and some shielding wall reconfiguration. The paper summarizes the most relevant activities done in preparation to the DP, with focus also on the logistics aspects related to the installation of a new machine while removing the old one (Elettra) being very closed to another operating one (FERMI).
Paper: WEPC31
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPC31
About: Received: 07 May 2024 — Revised: 17 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
WEPC40
Development of a hybrid thermionic and photoemission electron gun and dedicated test stand for ELSA
2050
A new electron gun is currently being designed for the S-band linac injector for ELSA. The objective of this development is to realize a new single-bunch injection mode in addition to the standard long pulse (multi-bunch) mode along with an improvement of the current beam parameters (e.g. emission current & transverse emittance) achieved by the existing gun. A dual mode design is being developed that utilizes a caesium dispenser cathode both as a thermionic and a photocathode using thermally assisted photoemission. In addition to the novel electron gun, a dedicated test stand is currently being designed to allow detailed characterization of both operating modes. The refined design of the gun and the current status of the test stand including beam parameter simulations are presented.
Paper: WEPC40
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPC40
About: Received: 15 May 2024 — Revised: 21 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
WEPC41
High average current DC electron gun for strong hadron cooling
2053
The Strong Hadron Cooling (SHC) for electron ion collider project requires a state-of-the-art high brightness DC electron gun. The gun is required to deliver high average current (98.5 mA), 1 mm∙mrad normalized transverse emittance and 1-2.5 nC bunch charge. In this paper, we describe the high voltage design of a DC gun with an operating voltage of 550 KV, to be conditioned up to 600 KV. Unique features of this gun includes the use of inverted ceramic in this level of voltage, active cooling for the cathode and use of large/single crystal multialkali cathode grown on Silicon-Carbide substrate. A test beam line for high current test is also described.
Paper: WEPC41
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPC41
About: Received: 15 May 2024 — Revised: 20 May 2024 — Accepted: 22 May 2024 — Issue date: 01 Jul 2024
WEPC53
Unconventional high-voltage insulator in DC photoemission sources
2083
Especially when a high average current of 1 mA and more is required, it is important to protect photocathodes from overheating due to the absorbed laser power. Heat must be dissipated via the surrounding components and materials. This is largely limited by the low heat conductivity of usual high-voltage insulators, e.g. made of aluminum oxide. At the Johannes Gutenberg University in Mainz, we have successfully tested an insulating structure from boron nitride. Due to its physical properties, boron nitride fulfills both requirements: good heat conduction and high-voltage resistance. The results of high voltage tests and of the heat transfer capabilities will be presented.
Paper: WEPC53
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPC53
About: Received: 13 May 2024 — Revised: 22 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
WEPC60
Status of the CARIE high gradient photocathode test facility at LANL
2101
This presentation will report on the status of assembling and commissioning of the Cathodes And Radio-frequency Interactions in Extremes (CARIE) C-band high gradient photoinjector test facility at Los Alamos National Laboratory (LANL). The construction of CARIE began in October of 2022. CARIE will house a high gradient copper RF photoinjector with a high quantum-efficiency cathode and produce an ultra-bright 250 pC electron beam accelerated to the energy of 7 MeV. The 50 MW 5.712 GHz Canon klystron will power the facility. The klystron was received and installed in fall of 2023. The WR187 waveguide line brings the power from the klystron into a concrete vault that is rated to provide radiation protection for an electron beam powers up to 20 kW. The first RF injector that was fabricated is made of copper and does not have cathode plugs. This injector will be commissioned to validate operation of the CARIE facility. The second injector that will accommodate cathode plugs and novel photocathodes was designed and will be fabricated. The status of the facility, the designs of the photoinjector and the beamline, and plans for photocathode testing will be presented.
Paper: WEPC60
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPC60
About: Received: 13 May 2024 — Revised: 17 May 2024 — Accepted: 17 May 2024 — Issue date: 01 Jul 2024
WEPC64
Towards operating low mean transverse energy (MTE) alkali antimonide photocathodes at Argonne Cathode Test-stand (ACT)
2116
The performance and scientific reach of advanced electron accelerator applications, such as particle colliders, x-ray free electron lasers, and ultrafast electron diffraction, are determined by beam brightness. The beam brightness is constrained by the quality of photocathodes and is associated with low Mean Transverse Energy (MTE) of photoemitted electrons. To meet the requirements for applications demanding a bright electron beam, photocathodes must exhibit ultrasmooth physical and chemical roughness, a long operational lifetime, and robustness under high applied electric fields and laser fluences. In this work, we present the development of an experimental setup for the growth and in-situ characterization of high-quality, low-MTE alkali antimonide photocathodes. Additionally, we describe the modifications made to the Argonne Cathode Test-stand (ACT) at the Argonne Wakefield Accelerator (AWA) Facility, necessary for studying the performance of alkali antimonide photocathodes under real photoinjector conditions.
Paper: WEPC64
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPC64
About: Received: 15 May 2024 — Revised: 24 May 2024 — Accepted: 24 May 2024 — Issue date: 01 Jul 2024
WEPC69
Developments and first results from an RF test stand for high brightness C-band photoguns at PSI
2133
An international collaboration between PSI and INFN-LNF has been undertaken with the aim of developing the next generation of high brightness electron sources. Through this collaboration, two unique high gradient RF photoguns that operate in the C-band frequency regime have been designed and realized. Concurrent to this, a new high power test stand at the Paul Scherrer Institut has been commissioned to test these novel devices. Here we report on the new test stand and the first results from the high-power testing of these devices.
Paper: WEPC69
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPC69
About: Received: 15 May 2024 — Revised: 22 May 2024 — Accepted: 22 May 2024 — Issue date: 01 Jul 2024
WEPG09
White X-ray beam position monitor for coherent soft X-ray beamlines
2195
A novel soft X-ray BPM (sXBPM) for high-power white beams of synchrotron undulator radiation has been developed through a joint effort of BNL/NSLS-II and Stony Brook University. In our approach, custom-made multi-pixel GaAs detector arrays are placed into the outer portions of the X-ray beam, and the beam position is inferred from the pixel photocurrents. Our goal is to achieve micron-scale positional resolution without interfering with user experiments, especially the most sensitive ones exploiting coherent properties of the beam. An elaborate mechanical system, which provisions for possible intercepts of kW-level beam in abnormal conditions, has been designed, fabricated, and installed in the 23-ID canted undulator beamline first optical enclosure. Separately, GaAs detectors with specially tailored spectral response have been designed, fabricated, and tested in the soft and hard X-ray regions at two NSLS-II beamlines. The paper gives an overview of the sXBPM system, presents the first results from the high-power white X-ray beam, and explains why our approach can be beneficial for XBPMs in future light sources with highly coherent beams.
Paper: WEPG09
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPG09
About: Received: 27 May 2024 — Revised: 28 May 2024 — Accepted: 28 May 2024 — Issue date: 01 Jul 2024
WEPG26
Overview of beam intensity issues and mitigations in the CERN-SPS fast wire scanners
2248
A new design of fast wire scanner was installed in the CERN injector complex as part of the upgrades linked to the High-Luminosity LHC Project. Initial operations with these beams were good, but during the planned intensity ramp-up one early 2023, all four SPS scanners failed at the same time. An urgent program was put in place to understand and address this failure with experts from across the accelerator fields. Many measurements and simulations were performed and solutions implemented. This paper gives an overview of the issues seen, understanding and mitigations put in place to allow the instrument to perform at the maximum planned operational intensities.
Paper: WEPG26
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPG26
About: Received: 13 May 2024 — Revised: 21 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
WEPG27
Real-time processing of longitudinal Schottky signals in CERN’s antiproton chain
2252
A low-latency, real-time diagnostic system for the analysis of longitudinal Schottky signals in CERN’s antiproton chain has been developed. The system, installed in CERN’s Antiproton Decelerator (AD), processes the combined output of two low-noise, wideband AC beam transformers. It uses a GPU and the NVIDIA CUDA Toolkit, exploiting the directly sampled data and hardware features provided by the low-level radio-frequency (LLRF) VMEBus Switched Serial (VXS) system and its companion ObsBox server, to implement the FFT-based multi-harmonic spectral analysis needed to set up and monitor the stochastic and electron cooling processes. Longitudinal beam properties, such as mean momentum and momentum spread, are also derived to evaluate and log the machine performance. This paper describes the implementation of the system and its integration within the CERN control system, achieved using the Front-End Software Architecture (FESA) framework and a graphics co-processor directly installed in the Front-End computer (FEC), running a real-time operating system environment. Preliminary results of its usage in the Extra Low ENergy Antiproton (ELENA) ring and next steps to process bunched beam spectra are also presented.
Paper: WEPG27
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPG27
About: Received: 02 May 2024 — Revised: 18 May 2024 — Accepted: 18 May 2024 — Issue date: 01 Jul 2024
WEPG28
Emittance and luminosity monitoring and modelling for LHC Run 3
2256
A comprehensive model accurately depicts and tracks emittance and luminosity evolution in the Large Hadron Collider (LHC), considering known effects like IBS, synchrotron radiation damping, coupling and incorporating data-driven factors on emittance growth and intensity losses. Used extensively in LHC Run 2, the model is updated for compatibility with new optics and operational schemes in Run 3, featuring luminosity leveling. This paper discusses the analysis of 2022 and 2023 LHC data, exploring emittance evolution and identifying extra blow-up at injection and collision energies compared to model predictions. Examining the model's agreement with collision data provides insights into the impact of degradation mechanisms, configuration options, filling schemes, and beam types on delivered luminosity. These studies offer valuable insights into potential gains in integrated luminosity for subsequent Run 3 years.
Paper: WEPG28
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPG28
About: Received: 15 May 2024 — Revised: 21 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
WEPG36
Mechanical design of the thermal imaging system for the FRIB target
2287
As the Facility for Rare Isotope Beams (FRIB) ramps up to 400 kW, a thermal imaging system (TIS) is essential to monitor the beam spot on the production target. The TIS is an array of mirrors and a telescope in the target vacuum chamber; this relays the image through a window to the optics module outside the chamber. The design presented many challenges from alignment, to remote installation of the TIS and integrated shielding, and repeatable re-installation of the mirror array and optics module. The target TIS has been in operation since 2021 and supports FRIB operations for secondary beam production, with incident power up to 10 kW. The temperatures seen validate the expected temperatures from analysis. The mechanical design of the FRIB target TIS is presented here as well as initial performance.
Paper: WEPG36
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPG36
About: Received: 14 May 2024 — Revised: 18 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
WEPG39
Ionization profile monitors for the IOTA proton beam
2299
We present the design details and outline the construction progress of the Ionization Profile Monitors (IPMs). Two IPMs, designed for transverse beam size measurements of 70 MeV/c protons, are slated for installation—one horizontal and one vertical—in the IOTA ring. These IPMs are fast (1.8 microsecond, one turn), accurate (to better than 10%) and non-destructive diagnostics. They will play a pivotal role in facilitating comprehensive beam studies, particularly in investigating the dynamics of space-charge dominated proton beams in IOTA.
Paper: WEPG39
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPG39
About: Received: 11 May 2024 — Revised: 20 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
WEPG55
Longitudinal phase space density tomography constrained by the Vlasov-Fokker-Planck equation
2350
Understanding the evolution of complex systems with numerous interacting particles requires advanced analytical tools capable of capturing the intricate dynamics of the phase space. This study introduces a novel approach to longitudinal phase space density tomography in an electron storage ring, leveraging constraints imposed by the Vlasov-Fokker-Planck equation. The Vlasov-Fokker-Planck equation provides a comprehensive description of the evolution of density functions in phase space, accounting for both deterministic and stochastic processes. Measurements of the turn-by-turn bunch profile offer a time-dependent projection of the phase space. Observing the bunch profile evolution of charged particles in regimes characterized by a rich phase space dynamics presents a challenging inverse problem for reconstructing the phase space densities. In this work, we present a tomographic framework for reconstructing the longitudinal phase space density of an electron bunch at the Karlsruhe Research Accelerator (KARA). This framework utilizes simulated data and applies the Vlasov-Fokker-Planck equation to drive the reconstruction process.
Paper: WEPG55
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPG55
About: Received: 13 May 2024 — Revised: 18 May 2024 — Accepted: 18 May 2024 — Issue date: 01 Jul 2024
WEPG72
Fast laser focal position correction using deployed models
2393
Ultrafast high repetition-rate laser systems are essential to modern scientific and industrial applications. Variations in critical figures of merit, such as focal position, can significantly impact efficacy for applications involving laser plasma interactions, such as electron beam acceleration and radiation generation. We present a diagnostic and correction scheme for controlling and determining laser focal position by utilizing fast wavefront sensor measurements from multiple positions to train a focal position predictor. We present the deployment and testing of this scheme at the BELLA Center at Lawrence Berkeley National Laboratory. Online optical adjustments are made to a telescopic lens to provide the desired correction on millisecond timescales. A framework for generating a low-level hardware description of ML-based correction algorithms on FPGA hardware is coupled directly to the beamline using the AMD Xilinx Vitis AI toolchain in conjunction with deployment scripts.
Paper: WEPG72
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPG72
About: Received: 16 May 2024 — Revised: 22 May 2024 — Accepted: 22 May 2024 — Issue date: 01 Jul 2024
WEPG95
Simulation of the C-band transverse deflection structure with variable polarization for super tau charm facility
2446
Transverse deflection structures (TDS) have been widely used as diagnostic devices to characterize longitudinal properties of electron bunches in a linear accelerator. However, the conventional TDS can only measure either the horizontal or the vertical slice envelopes of electron bunches. In order to give full control of the angles of the transverse streaking field inside of the TDS to characterize the projections of the beam distribution on different transverse axes, we numerically investigate an X-band TDS with variable polarization in this paper. Through variable streaking direction, the orientation of the streaking field of the TDS is adjusted to an arbitrary azimuthal angle. This helps facilitate the development of next-generation TDS for the characterization of electron bunches, such as slice emittance measurement on different planes.
Paper: WEPG95
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPG95
About: Received: 14 May 2024 — Revised: 22 May 2024 — Accepted: 22 May 2024 — Issue date: 01 Jul 2024
WEPR10
First FCC-ee lattice designs with Nested Magnets
2477
The Future Circular Electron-Positron Collider (FCC-ee) represents a cutting-edge particle physics facility designed to further investigate the Z, W± and Higgs boson in addition to the top quark. The implementation of Nested Magnets (NMs) in the FCC-ee arc cells would maintain high luminosity and reduce its energy consumption. The use of these special magnets induces changes in the damping partition numbers. To mitigate this the dipole fields in focusing and defocusing quadrupoles have to be different. This solution gives rise to incompatibility problems for the machine layout between the different energy configurations as the optics is also changed. This problem is tackled by defining different bending and geometric angles for the NMs. The beam dynamics and performance aspects of the new lattice are studied in this paper.
Paper: WEPR10
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPR10
About: Received: 15 May 2024 — Revised: 20 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
WEPR17
DAFNE operation strategy for the observation of the kaonic deuterium
2504
DAFNE, the Frascati F-factory the collider where the Crab-Waist collision scheme has been implemented and successfully tested, is presently working for a physics program in the field of exotic atoms. The present scientific program foresees the study and the characterization of the never observed before kaonic deuterium. Providing a suitable data sample for such measurement requires the collider to provide the highest flux of k- meson and the lowest possible background shower on the detector. The operation strategy, and the collider setup in terms of collisions and beam dynamics are presented and discussed.
Paper: WEPR17
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPR17
About: Received: 15 May 2024 — Revised: 20 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
WEPR20
Probing FCC-ee energy calibration through resonant depolarization at KARA
2516
The FCC-ee collider physics program requires a precise determination of the center-of-mass energy. The average energies of the two colliding beams can be measured by resonant depolarization (RDP) of polarized electron and positron bunches. The depolarization is achieved by an electromagnetic device, e.g., a strip line, excited at a sweeping frequency. Once the excitation frequency is equal to the spin precession frequency, which is directly proportional to the beam energy, the polarization is lost or reduced. At KARA the resonant frequency is routinely measured via the change of the Touschek lifetime. We report on an RDP beam measurement campaign at the Karlsruhe Research Accelerator (KARA), exploring how this technique could be applied at the FCC-ee. In particular, we examine the sensitivity of the inferred value of beam energy to various parameters, such as the depolarize scan speed, the scan direction, and the beam operation energy.
Paper: WEPR20
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPR20
About: Received: 14 May 2024 — Revised: 18 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
WEPR25
Conceptual RF design and modelling of a 704 MHz cavity for the muon cooling complex
2532
The Muon Cooling Complex is a crucial component of the future high-energy Muon Collider, where the ionization cooling technique is employed to reduce muon beam emittance by several orders of magnitude. This cooling technique necessitates the utilization of normal conducting, RF-accelerating cavities operating within a multi-Tesla magnetic field. This study illustrates the conceptual RF design of a 704 MHz copper cavity equipped with beryllium windows for the muon cooling demonstrator. Based on the specifications from the beam dynamics, frequency-domain eigenmode simulations have been conducted to calculate the primary RF figure of merits for the cavity. Subsequently, the cavity geometry has been optimized based on the results obtained from the eigenmode simulations. In a selected case, more advanced engineering analyses, including thermo-mechanical and Lorentz Force Detuning (LFD) simulations, have been performed to enable operation at gradients of up to 44 MV/m within strong solenoidal magnetic fields of up to 7.2 T.
Paper: WEPR25
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPR25
About: Received: 15 May 2024 — Revised: 18 May 2024 — Accepted: 18 May 2024 — Issue date: 01 Jul 2024
WEPR26
Radiation shielding studies for superconducting magnets in multi-TeV muon colliders
2536
Circular muon colliders provide the potential to explore center-of-mass energies at the multi-TeV scale within a relatively compact footprint. Because of the short muon lifetime, only a small fraction of stored beam particles will contribute to the physics output, while most of the muons will decay in the collider ring. The resulting power carried by decay electrons and positrons can amount to hundreds of Watt per meter. Dedicated shielding configurations are needed for protecting the superconducting magnets against the decay-induced heat and radiation damage. In this paper, we present generic shielding studies for two different collider options (3 TeV and 10 TeV), which are presently being explored by the International Muon Collider Collaboration. We show that the key parameter for the shielding design is the heat deposition in the magnet cold mass, which will be an important cost factor for facility operation due to the associated power consumption.
Paper: WEPR26
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPR26
About: Received: 15 May 2024 — Revised: 17 May 2024 — Accepted: 18 May 2024 — Issue date: 01 Jul 2024
WEPR34
An engineering prototype of a late stage ionization cooling cell for a muon collider
2564
Achieving the low emittances necessary for a muon collider requires ionization cooling. Much of that cooling occurs in compact cooling cells where superconducting coils and conventional RF cavities are closely interleaved [1]. The real challenges for these cooling cells reside in their engineering challenges: high field solenoids, RF cavities, and absorbers, often designed near technological limits, placed in close proximity to each other. We thus propose to build a prototype ionization cooling cell to demonstrate the capability of constructing an ionization cooling channel reaching the lowest emittances and to provide engineering input for the design of such beamlines. The magnets and cavities will be powered at their design values, and an absorber will be included along with a mechanism for heating the absorber similarly to how a beam would.
Paper: WEPR34
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPR34
About: Received: 15 May 2024 — Revised: 22 May 2024 — Accepted: 22 May 2024 — Issue date: 01 Jul 2024
WEPR38
Conceptual design of the HTS split coil test facility for the Muon Collider cooling section
2575
The cooling section of the Muon Collider requires a number of solenoidal coils of various diameters (0.05-2 m) and fields (2-60 T). An unusual feature of the cooling section is that the RF cavities operates under the large magnetic fields and field gradients generated by the focusing elements. Here we present the design of a test facility based on split coils, wound with HTS, to study the performance of RF cavities under magnetic field. The main characteristics are: 330 mm free room temperature bore, uniform 7 T field along 300 mm on axis, coils energized with parallel or antiparallel field: this last configuration provides a gradient field of about 40 T/m. The use of HTS in form of REBCO tape enables magnet operation at 20 K and cooling via solid conduction by cryocoolers. This facility will be a first prototype of the cooling cell magnets that are being designed in cryogen-free layout at 20 K for energy saving and will allow to anticipate system integration concepts. The conceptual design of the facility is almost frozen and the engineering design is well under way. If we get financial support by 2025 we can commission the facility in 2027.
Paper: WEPR38
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPR38
About: Received: 20 May 2024 — Revised: 24 May 2024 — Accepted: 24 May 2024 — Issue date: 01 Jul 2024
WEPR42
Optimizing Touschek lifetime with overstretched bunch profiles in the MAX IV 1.5 GeV ring
2586
Synchrotron light sources often use higher-harmonic rf cavities for bunch lengthening to enhance Touschek lifetime. By adjusting the harmonic voltage, a flat-potential condition for the longitudinal voltage can be achieved, typically improving Touschek lifetime by 4 to 5 times. It is known that exceeding the flat-potential voltage results in double-peaked bunch profiles, referred to as overstretched conditions. Simulations suggest overstretched profiles can surpass flat-potential improvements on lifetime. In this paper we report on experimental results from the MAX IV 1.5 GeV storage ring, demonstrating a longer beam lifetime with a stable beam in overstretched conditions compared to the flat-potential case. Additionally, a remarkable agreement between measured bunch profiles using a streak camera and predictions from a semi-analytical equilibrium solver was obtained for all tested harmonic voltages.
Paper: WEPR42
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPR42
About: Received: 15 May 2024 — Revised: 19 May 2024 — Accepted: 19 May 2024 — Issue date: 01 Jul 2024
WEPR44
Understanding of the new horizontal instability at the PS Booster after LIU
2594
Following the LHC Injectors Upgrade (LIU) project at CERN, the Proton Synchrotron Booster (PSB) has been upgraded to operate with a new injection kinetic energy of 160 MeV and an extraction energy of 2 GeV. To understand the performance of the accelerator in this new energy range, a series of measurements have been conducted, especially devoted to the beam stability to ensure the optimal operation of the machine. A horizontal instability, firstly observed in 2021 at about 1.6 GeV (between the old and the new extraction energy of the Proton Synchrotron Booster), has undergone in-depth investigation in measurements. Despite the identification of a mitigation strategy to cure the horizontal instability, efforts have also been focused to understand its source. The results have once again drawn the attention to the termination of the extraction kicker. As happened in 2018, a dedicated MD performed at the end of 2023 run with matched kicker termination confirmed the impact of the extraction kicker in this instability.
Paper: WEPR44
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPR44
About: Received: 10 May 2024 — Revised: 23 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
WEPR45
Observation of a synchro-betatron instability in Fermilab booster
2598
In preparation for PIP2, there has been interest in running the Fermilab Booster at a higher current more indicative of the PIP2 era operation. In July 2023 an experiment was performed to study collective instabilities over the transition crossing at the Fermilab Booster. Over the transition crossing, the synchrotron tune becomes small and synchro-betatron instabilities become possible. During the experiment, an intensity threshold was observed, above which a dipole instability with losses concentrated in the tail of the bunch. These losses are consistent with the Convective Instability.
Paper: WEPR45
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPR45
About: Received: 14 May 2024 — Revised: 18 May 2024 — Accepted: 19 May 2024 — Issue date: 01 Jul 2024
WEPR53
H- source characterization and transfer line studies with realistic EM fields in the ELENA decelerator at CERN
2616
A local H- /p source is operated at the CERN Extra Low Energy Antiproton (ELENA) decelerator for commissioning the ring and subsequent electrostatic transfer lines toward the experiments. For proper optics characterization, it is important to have a detailed knowledge of the H- beam parameters at the source. Phase space tomography techniques were applied to reconstruct the beam distribution at the measurement point, which was then tracked backward to the H- source using symplectic field maps to calculate the beam matrix. Due to the presence of an ion switch a highly non-linear behavior with significant deviation from the linear model was observed. The SIMPA tracking code allows EM fields in the transfer line to be treated continuously and as a whole.
Paper: WEPR53
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPR53
About: Received: 08 May 2024 — Revised: 18 May 2024 — Accepted: 18 May 2024 — Issue date: 01 Jul 2024
WEPR76
Beam loading mitigation with digital direct RF feedback at ALBA
2688
A digital direct RF feedback (DDRF) has been implemented in the DLLRF of the ALBA synchrotron light source in order to mitigate the beam loading effects of the beam. Specifically, with the DDRF implemented in the main cavities, the tune shift due to beam loading can be minimized and therefore the DC-Robinson instability can be mitigated. It can also be used to minimize voltage drops in case of transients after a cavity loss during the operation. Also, for the next generation machine ALBA-II and applied to the active 3rd harmonic system, it can be used to fight against AC-Robinson instability induced by the harmonic cavities, increasing the damping rate of the fundamental CBI mode, and reducing the transient beam loading effects. In this contribution we present measurements with beam of the DDRF applied to ALBA main cavities, demonstrating a reduction of a factor two in the effective impedance of the cavity as seen by the beam.
Paper: WEPR76
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPR76
About: Received: 15 May 2024 — Revised: 20 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
WEPS01
High-intensity polarized and unpolarized H⁻ sources development and operation at BNL
2691
The AGS-RHIC injector complex includes H- ion sources at 35 keV, 750 keV RFQ and 200 MeV Linac. This report will focus on the recent upgrade of the 35 KeV Low Energy Beam Transport (LEBT) with three sources: two high-intensity magnetron H- sources and an Optically Pumped Polarized Ion Source (OPPIS) polarized H- source. There were still significant beam intensity losses in the 8 m long OPPIS transport line due to H- stripping, therefore, to meet the demand for the higher beam intensity in the 2024 polarized run, the OPPIS LEBT length was reduced by about two meters. Another possibility for increasing beam intensity is to increase the beam pulse width. The sources performance and operation in Run-2024 will be presented.
Paper: WEPS01
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPS01
About: Received: 15 May 2024 — Revised: 22 May 2024 — Accepted: 22 May 2024 — Issue date: 01 Jul 2024
WEPS04
A faster initial cesium transfer for the LANSCE H⁻ ion source
2698
The LANSCE H- Ion Source utilizes a cesium coated converter to induce H- surface conversion. To achieve an optimal cesium coating, a heated cesium reservoir and transfer tube vaporizes cesium onto the converter surface. An initial coating of cesium is done via an initial cesium transfer. During this process, the cesium heater is brought to a high initial temperature (250°C) and is slowly lowered to the operational temperature (~190°C) over six hours, followed by a static conditioning for another 18 hours to get the cesium converter coating optimal for H- surface conversion. Any reduction in the 24-hour cesium transfer process would allow more for experimental time for LANSCE experiments. Thus, there is high value in seeking to reduce the initial Cs transfer time. The LANSCE H- Ion Source Laser Diagnostic Stand was recently utilized to take cesium density measurements inside the H- Ion Source as a function of cesium reservoir temperature. A comparison of the measured cesium densities to the theoretical cesium vapor pressure values will be presented. Also, results using the measured cesium densities to calculate and run a faster cesium transfer process will be discussed.
Paper: WEPS04
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPS04
About: Received: 15 May 2024 — Revised: 22 May 2024 — Accepted: 22 May 2024 — Issue date: 01 Jul 2024
WEPS09
Niobium-tin as a transformative technology for low-beta linacs
2709
Niobium-tin has been identified as the most promising next-generation superconducting material for accelerator cavities. This is due to the higher critical temperature (Tc = 18 K) of Nb3Sn compared to niobium (TC = 9.2 K), which leads to greatly reduced RF losses in the cavity during 4.5 K operation. This allows two important changes during cavity and cryomodule design. First, the higher Tc leads to negligible BCS losses when operated at 4.5 K, which allows for a higher frequency to be used, translating to significantly smaller cavities and cryomodules. Second, the reduced dissipated power lowers the required cryogenic cooling capacity, meaning that cavities can feasibly be operated on 5-10 W cryocoolers instead of a centralized helium refrigeration plant. These plants and distribution systems are costly and complex, requiring skilled technicians for operation and maintenance. These fundamental changes present an opportunity for a paradigm shift in how low-beta linacs are designed and operated. Fabrication challenges and first coated cavity test results are discussed.
Paper: WEPS09
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPS09
About: Received: 15 May 2024 — Revised: 21 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
WEPS10
Installation and commissioning of the APS-U bunch lengthening system
2713
A new bunch lengthening cryomodule based a sin-gle-cell superconducting (SC) cavity operating at the 4th harmonic (1408 MHz) of the main RF has been installed into Argonne’s Advanced Photon Source (APS) storage ring as part of the U.S. DOE APS Up-grade project. The beam-driven system will be used to improve the Touschek lifetime by increasing the bunch length by up to several times. The 2-meter-long cryomodule is installed into one half of an APS straight section. The cavity will run at 2.1 K and pro-vide up to 1.3 MV of potential for bunch lengthening in a storage ring mode with a beam current of 200 mA evenly distributed into 48 bunches. System features include a pneumatic slow mechanical tuner and a pair of adjustable RF power couplers to adjust both the frequency and the loaded quality factor, providing a means of stabilizing the beam over a range of beam currents and fill patterns. Beam induced higher-order modes (HOMs) will be extracted along the beam axis and damped using a pair of room temperature silicon carbide absorbers. Cryogenic cooling is being provid-ed by a new 4.3 K liquid helium refrigerator combined with vacuum pumping and J-T expansion inside the cryomodule. We summarize the system features and report some results of initial cool down, testing, and measurements with beam.
Paper: WEPS10
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPS10
About: Received: 15 May 2024 — Revised: 18 May 2024 — Accepted: 18 May 2024 — Issue date: 01 Jul 2024
WEPS20
Field emission experience, statistics and challenges with ESS elliptical cryomodules
2739
ESS elliptical cryomodules, CEA-INFN-STFC in-kind contribution, undergo site acceptance test at ESS Lund Test Stand (TS2). Here the Field Emission operation experience, modules performances statistics and limiting mechanism, diagnostics equipment and analysis tool are described. High energy field emission and dose rate operational challenges and long-term superconducting LINAC operational strategy are described.
Paper: WEPS20
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPS20
About: Received: 19 May 2024 — Revised: 23 May 2024 — Accepted: 24 May 2024 — Issue date: 01 Jul 2024
WEPS21
Coupler HV bias studies on ESS elliptical cavities
2743
We study the effects of high voltage DC bias on the fundamental power couplers of the ESS elliptical SRF cavities. These tests were carried out at the TS2 facility, where cryomodule acceptance and characterization tests are carried out. We present the observed effects of positive and negative bias field on multipacting in the RF couplers, as well as the implications for operation in the ESS linac.
Paper: WEPS21
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPS21
About: Received: 17 May 2024 — Revised: 18 May 2024 — Accepted: 18 May 2024 — Issue date: 01 Jul 2024
WEPS26
Results from extended range SRF cavity tuner tests for LCLS-II-HE
2751
The LCLS-II HE superconducting linac can produce multi-energy beams by supporting multiple undulator lines simultaneously. This could be achieved by using the cavity SRF tuner in the off-frequency detune mode. This off-frequency operation method was tested in 8 cryomodules at Fermilab at 2 K. In all the tests the tuners successfully achieved a frequency shift of -565±80 kHz from the 1.3 GHz value. This study discusses the cavity frequency during each stage of assembly from the cryomodule string to when they are finally tested at 2 K. Monitoring the cavity frequency from this initial stage contributed in reaching this large frequency shift. The specific procedures of tuner setting during assembly will be presented.
Paper: WEPS26
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPS26
About: Received: 14 May 2024 — Revised: 20 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
WEPS37
REBCO sample testing at high power X-band
2772
SRF materials such as niobium have been extremely useful for accelerator technology but require low temperatures operation < 9 K. The development of high temperature superconductors (HTS) is promising due to their to their high critical temperature 89.5 K. This work intends to determine the high-power RF performance of such materials at X-band (11.424 GHz). Two kinds of REBCO coatings (thin film deposition and soldered tapes) on a copper substrate were tested. Testing was done in a hemispherical TE mode cavity due to its ability to maximize the magnetic field on the sample and minimize the electric field. We will report conductivity vs temperature at low and high power. We determine the quench field in the REBCO sample and explain the evidence which shows that the quenching is most likely due to reaching the critical current and not due to average applied heat load for powers up to 1.6 kW.
Paper: WEPS37
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPS37
About: Received: 14 May 2024 — Revised: 19 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
WEPS39
V₃Si: an alternative thin film material for superconducting RF cavities
2779
Superconducting materials, like V3Si, NbN, NbTiN and Nb3Sn, are potential alternatives to Nb for next generation thin film SRF cavities. In comparison to the Nb, their relatively high Tc could allow for operation at higher temperatures (≥ 4 K) and the higher critical field could lead to for higher accelerating gradients. We investigate optimum deposition parameters and substrates for V3Si, using single target physical vapor deposition (PVD). We report on the superconducting properties such as Tc and surface resistance using RRR and low power RF, stoichiometry using RBS, SIMS, XPS and EDX and surface quality using AFM and white light interferometry.
Paper: WEPS39
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPS39
About: Received: 15 May 2024 — Revised: 19 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
WEPS41
Design, construction and operation of a surface-treatment platform for SHINE superconducting cavities
2785
The SHINE project requires more than six hundred 1.3GHz cavities and sixteen 3.9GHz cavities for the superconducting accelerator. These cavities are from both domestic and foreign companies. The cavities fabricated in domestic companies requires correspond-ing capacity of surface-treatment. For the R&D of surface-treatment technology and mass production of SRF cavities, we have been constructing a new surface-treatment platform near Shanghai for SHINE project. In this paper, we report the design, construction, commissioning and operation of this platform.
Paper: WEPS41
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPS41
About: Received: 15 May 2024 — Revised: 16 May 2024 — Accepted: 17 May 2024 — Issue date: 01 Jul 2024
WEPS52
In situ plasma processing of superconducting cavities at JLab, 2024 update
2814
Jefferson Lab has an ongoing R&D program in plasma processing. The experimental program investigated processing using argon/oxygen and helium/oxygen gas mixtures. Plasma processing is a common technique where the free oxygen produced by the plasma breaks down and removes hydrocarbons from surfaces. This increases the work function and reduces the secondary emission coefficient. The initial focus of the effort was processing C100 cavities by injecting RF power into the HOM coupler ports. We also developed the methods for establishing a plasma in C75 cryomodules where the RF power is injected via the fundamental power-coupler. Four C100 cryomodules were in-situ processed in the CEBAF accelerator in May 2023 with the cryomodules returning to an operational status in Sept. 2023. The overall operational energy gain for the four cryomodules was 49 MeV. Methods, systems and results from processing cryomodules in the CEBAF accelerator and vertical test results will be presented. Current status and future plans will also be presented.
Paper: WEPS52
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPS52
About: Received: 14 May 2024 — Revised: 22 May 2024 — Accepted: 22 May 2024 — Issue date: 01 Jul 2024
WEPS61
Mapping the stray magnetic field at the Relativistic Heavy Ion Collider tunnel
2836
A new Rapid Cycling Synchrotron (RCS) [1] is designed to accelerate the electron bunches from 400 MeV up to 18 GeV for the Electron Ion Collider (EIC) [2] being built at Brookhaven National Laboratory (BNL). One of the two Relativistic Heavy Ion Collider (RHIC) rings will serve as the Hadron Storage Ring (HSR) of the EIC. Beam physics simulations for the RCS demonstrate that the electron beam is sensitive to the outside magnetic field in the tunnel. Significant magnetic fields are expected due to the HSR and the Electron Storage Ring (ESR) being at full energy during the RCS operation. The earth magnetic field at the location of the RCS center was measured throughout the circumference of 3870 m tunnel without RHIC operation. In addition, the fringe magnetic field from RHIC magnets at several locations during RHIC operation was measured and compared with simulation at different ramping currents. A robotic technology is being developed to automatically measure the stray magnetic field at any location during the RHIC (or future EIC) operation.
Paper: WEPS61
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPS61
About: Received: 15 May 2024 — Revised: 20 May 2024 — Accepted: 20 May 2024 — Issue date: 01 Jul 2024
WEPS62
Superconducting dipole for Elettra 2.0
2840
Elettra 2.0 is the 4th generation synchrotron light source that is going to replace Elettra, the 3rd generation light source operating for 30 years in Trieste Italy. The new ring will be giving light to the users in 2026 at 2.4 GeV. Three beam lines require very hard-x-rays i.e. photon energies at 50 keV or more with a flux of 1013 ph/sec and this can be achieved with a superconducting magnet at 6 T peak field. A new superconducting magnet is developed with an innovative compact design integrated with quadrupole side magnets. A new cryogenic solution will combine the benefits of a liquid-helium cooled inner magnet with a liquid-helium-free upper cooling stage. A C-shaped design will allow to slip in and slip out the magnet from its position on the storage ring vacuum chamber. A prototype of a new 6T superconducting magnet will be constructed and installed in the storage ring to replace a normal 1.4 T magnet allowing a full characterization of its performance. The NbTi superconducting magnet will work at 3.5K conduction cooled, using a system of heat exchanger connected to a subcooled Helium bath.
Paper: WEPS62
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPS62
About: Received: 14 May 2024 — Revised: 20 May 2024 — Accepted: 20 May 2024 — Issue date: 01 Jul 2024
WEPS67
Status of coil-dominated discrete-cosine-theta quadrupole prototype for high rigidity isotope beams
2854
Iron-dominated superconducting magnets are one of the most popular and used design choices for superconducting magnetic quadrupoles for accelerator systems. While the iron yoke and pole tips are economic and effective in shaping the field, the large amount of iron also leads to certain drawbacks, namely, unwanted harmonics from the sextupole correctors nested inside of quadrupole iron pole tips. Additional problems include the nonlinear field profile present in the high-field regime caused by the presence of steel, the cryogenic design challenges of the iron yoke being part of the cold mass, and the mechanical challenges of mounting the sextupole and octupole, which will generate significant forces for apertures of the size being proposed. The Facility for Rare Isotope Beams is developing a coil dominated quadrupole as a future upgrade, and the presented work discusses the advantages of using an iron-free quadrupole, along with the methods and choices of the design and the current status of prototype fabrication. The methods and work presented will include the model results and the aspects of the model that have been verified up to the current status of prototype fabrication.
Paper: WEPS67
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPS67
About: Received: 15 May 2024 — Revised: 22 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
WEPS71
Superconducting magnets for SIS100 and Super-FRS at FAIR – overview and progress
2862
At the FAIR project in Darmstadt, Germany, superconducting magnets will be utilized for the main accelerator, the SIS100 heavy ion synchrotron, and for the fragment separator Super-FRS. For SIS100, the magnets are fast ramped with a rate of up to 4 T/s while large apertures are required for Super-FRS. In total, several hundred magnets need to be produced, qualified and characterized for the operation at FAIR. For both machines, series production is ongoing and testing programs at operational conditions have been established for quality assurance of the high demanding magnet modules. In the presentation, an overview is given on the design and operation principles of the various magnet types and module combinations. The complex project landscape involving several sites for production, module integration, and cold testing is pictured. The project progress and key testing results are highlighted and an outlook for the installation and commissioning plans at FAIR is given.
Paper: WEPS71
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPS71
About: Received: 15 May 2024 — Revised: 19 May 2024 — Accepted: 19 May 2024 — Issue date: 01 Jul 2024
WEPS72
Thermal studies of the magnet quenches of the SuperKEKB beam final focus system
2866
The beam final focus system of SuperKEKB consists of 55 superconducting magnets. They are 8 main quadrupole magnets, 43 corrector magnets and 4 compensation solenoids. During beam operation from 2018 to 2022, the superconducting magnets quenched 40 times induced by the electron or positron beam hitting the superconducting coils or the other disturbances. The temperatures of the quenched superconducting coils are being studied with the accumulated magnet quench data and the conditions of beam operation. The temperatures of the coils are evaluated with the critical temperature defined by the operation magnetic field and the transport current. The authors will report the temperature range of the superconducting coil shortly after the coil quench.
Paper: WEPS72
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPS72
About: Received: 15 May 2024 — Revised: 18 May 2024 — Accepted: 18 May 2024 — Issue date: 01 Jul 2024
WEPS73
Time decay effect of the superconducting final focus quadrupole fields on SuperKEKB beam operation
2868
SuperKEKB is the particle collider of electrons at 7 GeV and positrons at 4 GeV, and it is the cutting-edge collider in the luminosity frontier using the “Nano-beam scheme”. The beam colliding operation of SuperKEKB started from 2018 May, and the peak luminosity reached at 4.678×1e-34 1/cm² 1/s with quite expert beam operation. In beam operation, the vertical tune of the positron beam was measured to decline exponentially with time just after exciting the final focus quadrupole magnets. To identify the source of the tune change, we performed the magnetic field measurements of the prototype final focus quadrupole magnets, and the exponential field change with time after exciting the magnets was measured and the measured field decay rates were found to be of equal size of the measured tune change during beam operation. Because the field change is due to the magnetization decay in the superconductor, NbTi, filament, we modified the excitation pattern of the magnets and canceled the field decay. We will report the measured beam tune changes, the prototype field measurement results and the condition of beam operation with the modified excitation patterns of the quadrupole magnets.
Paper: WEPS73
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPS73
About: Received: 15 May 2024 — Revised: 20 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
WEPS78
First year of data taking with the electricity meter network for sustainable operation of the KIT accelerator facilities for the KITTEN project
2883
In times of climate change and with increasing challenges of the power grid stability due to unstable renewable energy sources, it is not sufficient to know the electric energy consumption of accelerator facilities. In order to optimize the operation of the research infrastructure in terms of stability, reliability and sustainability, the knowledge of the dynamics of energy consumers, and generators is mandatory. Since a few years, KIT's accelerator teams collaborate with its EnergyLab 2.0, Europe's largest research infrastructure for renewable energies, within the KIT test field for energy efficiency and grid stability of large-scale research infrastructures (KITTEN). At the research accelerators KARA and FLUTE a dense network of power meters, more than 100 sensors of different kind, operate to observe from individual components to infrastructural components and the central electricity distribution. With more than one year of data taking for most of the sensors, we are already able to quantify implemented energy-savings measures. In this contribution the findings of the installation and the first analysis and savings within the more than one year data taking will be presented.
Paper: WEPS78
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPS78
About: Received: 15 May 2024 — Revised: 22 May 2024 — Accepted: 22 May 2024 — Issue date: 01 Jul 2024
WEPS79
Optimization studies on accelerator sample components for energy management purposes
2887
The large amount of energy required to operate large-scale facilities with particle accelerators within has been considered as one of the important research topics over the past years. This sheds light on the importance of the research field of energy management that entitles, with a view to long-term operations, the implementation of smart and sustainable technologies. One of the key technologies in accelerators are superconductor (SC)-based designs. The vanishing electrical resistance together with the ability to provide field values well above those from conventional conductors is the main motivation behind exploiting superconducting wires in building coils and magnets for large-scale accelerators. However, these superconductors can also quench under certain conditions, driving the wires into the normal state and potentially allowing for overheating and destruction of the conductor material and/or the whole design. This work will present the results of optimization-based analyses performed on accelerator SC-sample components aiming at goal designs that are more energy efficient at a reference operational field or current. A compromise between getting the best performance for excellent science from a design (with superconductivity preserved and safe operation maintained) and reducing its power consumption (and eventually its effective cost) will be addressed too.
Paper: WEPS79
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPS79
About: Received: 15 May 2024 — Revised: 16 May 2024 — Accepted: 16 May 2024 — Issue date: 01 Jul 2024
WEPS80
Lessons learned from hardware failure during HL-LHC AUP cabling
2891
The cabling facility at Lawrence Berkeley National Laboratory has experienced a heavy increase in workload during the US-HiLumi Accelerator Upgrade Project (AUP). Several critical components have experienced unexpected failure over the project’s lifetime for reasons at least partly attributable due to increased wear and tear on the hardware subsystems. This work presents three case studies of varying severity and lessons learned from each failure. Suggested strategies to ensure operational readiness and uptime for legacy systems are also discussed.
Paper: WEPS80
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPS80
About: Received: 15 May 2024 — Revised: 23 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
WEPS81
Optimizing the magnetic circuit of HTSU through REBCO tape selection
2895
The National Synchrotron Radiation Research Center (NSRRC) has conducted a study on the magnetic circuit design of a high-temperature superconducting undulator (HTSU). This study explores the potential use of second-generation high-temperature superconducting (2G-HTS) materials in undulator magnet, which offer advantages such as higher current density and operating temperature. To evaluate the feasibility of HTSU design, a preliminary magnetic circuit analysis has been conducted. The simulation of the HTSU involved the use of several commercial 2G-HTS tapes with different widths. Insulating and non-insulating HTS tapes were compared to evaluate their effects on current density and magnetic field. Additionally, the maximum field strength on the surface of the tape was determined to establish the optimal operating temperature and current density for the HTSU. These simulation results provide valuable insights for optimizing the design and performance of the HTSU, ultimately contributing to advancements in particle accelerator technologies.
Paper: WEPS81
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPS81
About: Received: 09 May 2024 — Revised: 17 May 2024 — Accepted: 17 May 2024 — Issue date: 01 Jul 2024
WEPS84
CERN accelerates sustainability
2906
CERN is pursuing several initiatives to reduce its impact on the environment through an integrated approach to address all the objectives set by the relevant United Nations (UN) Sustainable Development Goals (SDG). In particular CERN is committed to respect the net-zero paradigm for future machines and has established a Sustainable Accelerators Panel to harmonize the approach to sustainability of the various studies for future accelerators. In this paper we will describe the efforts taken in managing responsibly our technical installations and the process we are setting up to perform the lifecycle assessment of the different future projects to better understand the main drivers of CO2 emissions in order to minimize them by design.
Paper: WEPS84
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPS84
About: Received: 15 May 2024 — Revised: 17 May 2024 — Accepted: 17 May 2024 — Issue date: 01 Jul 2024
WEPS85
An update on IRIS demonstrators
2909
IRIS (Innovative Research Infrastructure on applied Superconductivity) is a major project to build a research infrastructure in applied superconductivity, recently approved in Italy and led by INFN Milano. In this framework, we are developing two superconducting energy savings devices, both working at 20 K either in helium gas flow or by cold-heads: An HTS dipole (Energy Saving Superconducting Magnet) and a 1 GW rated superconducting line (Green SuperConducting Line). ESMA is an HTS ReBCO metal insulated racetrack dipole, this magnet will be 1 m long with a medium-sized round bore of 70 mm diameter and a maximum central field of 10 T. The paper reports the design updates, presenting and discussing the main technological choices (coil layout, ramping time, etc.). An R&D plan is supporting the technology choices and the construction that will be carried out in Industry will also be included. We are also developing a 130 m long MgB2 Superconducting Line (GSCL), capable of carrying 40 kA at 25 kV, an almost zero-dissipation DC transmission line. The paper will present the up-to-date status of the IRIS energy-saving devices, ESMA and GSCL: design, tests, and production.
Paper: WEPS85
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPS85
About: Received: 20 May 2024 — Revised: 23 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
WEPS86
A life cycle assessment of the ISIS-II neutron and muon source
2912
The ISIS-II Neutron and Muon source is the proposed next generation of, and successor to, the ISIS Neutron and Muon Source based at the Rutherford Appleton Laboratory in the United Kingdom. Anticipated to start construction in 2031, the ISIS-II project presents a unique opportunity to incorporate environmental sustainability practices from its inception. A Life Cycle Assessment (LCA) will examine the environmental impacts associated with each of the ISIS-II design options across the stages of the ISIS-II lifecycle, encompassing construction, operation, and eventual decommissioning. This proactive approach will assess all potential areas of environmental impact and seek to identify strategies for minimizing and mitigating negative impacts, wherever feasible. This presentation will provide insights into the process and first results of the LCA of the entirety of the ISIS-II project.
Paper: WEPS86
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-WEPS86
About: Received: 15 May 2024 — Revised: 23 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
THAN1
Design, realization and high power RF test of the new brazed free C band photo-gun
2929
RF photo-gun are the electron beam sources of FELs or Compton facilities. They are key components and, presently, the RF technology mostly used for these devices is the S band (3 GHz) with typical cathode peak fields of 80-120 MV/m and repetition rates lower than 100-120 Hz. An innovative C-Band (5.712 GHz) RF gun aiming at reaching cathode peak field larger than 160 MV/m, with repetition rates exceeding the 400 Hz, has been designed, realized and high power tested in the context of the European I.FAST and INFN Commission V projects. It is a 2.5 cell standing wave cavity with a four-port mode launcher, designed to operate with short RF pulses (300 ns). Its realization is based on the new brazed-free technology developed and successfully tested at INFN. In the paper, after a short overview of the design and RF gun capabilities, we illustrate the realization procedure and the results of the high power RF tests that have been done at the high power C band test facility at PSI (Switzerland).
Paper: THAN1
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THAN1
About: Received: 15 May 2024 — Revised: 21 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
THYN1
First results of AUP Nb3Sn quadrupole horizontal tests
2943
The Large Hadron Collider will soon undergo an upgrade to increase its luminosity by a factor of ~10. A crucial part of this upgrade will be replacement of the NbTi final focus magnets with Nb3Sn magnets that achieve a ~50% increase in the field strength. This will be the first ever large scale implementation of Nb3Sn magnets in a particle accelerator. This talk will present the program to fabricate these components and first results from horizontal tests of fully assembled cryoassemblies.
Paper: THYN1
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THYN1
About: Received: 15 May 2024 — Revised: 21 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
THBD2
Bunch lengthening induced by a combination of higher-harmonic cavities of different order in low-emittance rings
2952
The next generation of light sources aim to provide bunch beams with small transverse emittances. A common feature in the design of light sources with small emittance lattices is the small value of the momentum compaction, which implies a short nominal equilibrium bunch length. Combined with the small transverse emittances, a short bunch length can pose severe limitations on the beam lifetime caused by collective effects such as intra-beam and Touschek scattering. To improve the beam lifetime of the bunches, an efficient way is to use a Higher-Harmonic Cavity (HHC) system, which leads to an increase of the equilibrium bunch length without an increase of the energy spread. Besides the improvement of beam lifetime, the HHC system plays an important role to cure beam instabilities and mitigate possible beam induced heating issues of the storage ring vacuum components. Present HHC systems are based on HHCs of the same order. To increase the bunch lengthening factor induced by the HHC system, we investigate a novel scheme based on the combination of HHCs of different order. The feasibility and performance of the novel scheme will be studied with the beam dynamics codes SPACE and Elegant, with parameters of the NSLS-II upgrade.
Paper: THBD2
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THBD2
About: Received: 15 May 2024 — Revised: 20 May 2024 — Accepted: 22 May 2024 — Issue date: 01 Jul 2024
THBN1
Progress in the design of the magnets for a Muon Collider
2956
Magnets have been identified as one of the critical technologies for a proton-driven Muon Collider. Within the scope of the International Muon Collider Collaboration we have progressed in the review of requirements, and the development of concepts towards the initial engineering of several of the most critical magnets identified from our previous work. In this paper we present an update of the accelerator magnet configuration for all the parts of the Muon Collider complex, from muon production to collision. We then give details on the specific technologies that have been selected as baseline. Overall, it is clear that a Muon Collider requires very significant innovation in accelerator magnet technology, mostly relying on the success of HTS magnet development. We include in our description a list of options and development staging steps intended to mitigate technical, cost and schedule risk.
Paper: THBN1
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THBN1
About: Received: 15 May 2024 — Revised: 22 May 2024 — Accepted: 22 May 2024 — Issue date: 01 Jul 2024
THPC09
Pulsed correctors for the beam vertical stability during injection in CESR
2982
Beam motion during injections could be a serious problem to x-ray users and jeopardize their experiments. In the Cornell Electron Storage Ring (CESR) the particles are injected with pulsed elements such as pulsed bumpers and septum which could cause transient motion of the stored beam. By analyzing the turn-by-turn position data of the stored beam acquired during injection, we identify the source of beam motion in different time scales. A new corrector coil is then designed to compensate the beam motion with 0.15 msec duration at a 60 Hz repetition rate in the vertical plane. In addition to the new corrector we also use one of the existing magnet coils to correct 60 Hz kicks and DC offsets. Although, during the last summer down the 60 Hz source was identified and suppressed by an order of magnitude, this corrector is still in use to minimize the injection transient. The waveforms, used to drive the correctors, are extracted based on the beam turn-by-turn coordinates and orbit kick analyses using the 110 CESR Beam Position Monitors data. In this paper we discuss the requirements and parameters of the new corrector, as well as the correction technique, which is proven to be effective.
Paper: THPC09
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPC09
About: Received: 15 May 2024 — Revised: 21 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
THPC12
Preparations of the Elettra booster for Elettra 2.0
2988
The low emittance ( 4th generation) light source Elettra 2.0, that will replace Elettra the 3rd generation light source in Trieste Italy, will be commissioned in 2026. However the injector complex will be conserved but improvements will be done in order to be ready before of the storage ring commissioning. Optics modification, hardware upgrade and software development will be undertaken to improve the performance, stability and reliability of the Injector complex
Paper: THPC12
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPC12
About: Received: 09 May 2024 — Revised: 19 May 2024 — Accepted: 19 May 2024 — Issue date: 01 Jul 2024
THPC22
Space charge dominated momentum spread and compensation strategies in the post-linac section of Proton Improvement Plan-II at Fermilab
3023
The upcoming Proton Improvement Plan-II (PIP-II), designated for enhancements to the Fermilab accelerator complex, features a Beam Transfer Line (BTL) that channels the beam from the linac exit to the booster. In the absence of longitudinal focusing beyond the superconducting linac, the beam experiences an elevated momentum spread, primarily due to nonlinear space-charge forces, surpassing the allowable limit of 2.1e-4. This study presents a detailed examination of the space-charge-induced momentum spread and outlines mitigative strategies. The investigation includes the fine-tuning of a de-buncher cavity, analyzed in terms of operating frequency, longitudinal location, and gap voltage, under both standard and perturbed beam conditions—specifically accounting for momentum jitter and energy variation. The impact of buncher cavity misalignments on the beam's longitudinal phase space is also assessed. The paper concludes by recommending an optimized cavity configuration to effectively mitigate the observed increase in momentum spread along the BTL.
Paper: THPC22
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPC22
About: Received: 15 May 2024 — Revised: 19 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
THPC23
Machine-assisted discovery of integrable symplectic mappings
3027
Integrable systems possess a hidden symmetry associated with the existence of conserved quantities known as integrals of motion. These systems play an important role in understanding general dynamics in accelerators and have potential for future designs. This work will cover two automated methods for finding integrable symplectic maps of the plane. The first algorithm is based on the observation that the evolution of an integrable system in phase space is confined to a lower-dimensional submanifold of a specific type. The second algorithm relies on an analysis of dynamical variables. Both methods rediscover some of the famous McMillan-Suris integrable mappings and ultra-discrete Painlev\'e equations. Over 100 new integrable families are presented and analyzed, some of which are isolated in the space of parameters, while others are families with one parameter (or the ratio of parameters) being either continuous or discrete. In addition, the newly discovered maps are related to a general 2D symplectic map through the use of discrete perturbation theory. A method is proposed for constructing smooth near-integrable dynamical systems based on mappings with polygon invariants.
Paper: THPC23
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPC23
About: Received: 15 May 2024 — Revised: 19 May 2024 — Accepted: 22 May 2024 — Issue date: 01 Jul 2024
THPC24
Optics corrections and performance improvements in the Bessy II Booster
3031
The BESSY II Booster has been reliably delivering beam to the storage ring for several decades. As part of an effort to better understand and control beam dynamics in the Booster, new instrumentation, including Libera Spark ERXR beam position processors, has recently been installed and commissioned. These instrumentation upgrades have enabled measurements and corrections of optics parameters throughout the acceleration ramp which were not previously possible, leading to understanding and mitigation of mechanisms for beam loss and instabilities. Here we describe the beam position measurement system, corrections to the tune and chromaticity, and the resulting improvements to the top-up operation of BESSY II.
Paper: THPC24
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPC24
About: Received: 13 May 2024 — Revised: 21 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
THPC39
Horizontal splitter design for FFA@CEBAF energy upgrade: current status
3082
Thomas Jefferson National Accelerator Facility (Jefferson Lab) is currently studying the feasibility of an energy upgrade based upon Fixed-Field Alternating Gradient (FFA) permanent magnet technology. The current plan is to replace the highest-energy recirculation arcs with FFA arcs, increasing the total number of beam recirculations, thus the energy. In order to accommodate multiple passes in the FFA arcs, horizontal splitters are being designed to control the beam parameters entering the FFA arcs, as well as time-of-flight and R56. In the current design, six passes will recirculate through the FFA arcs, necessitating the design of six independent beamlines to control the optics and beam dynamics matching into the arcs. These beamlines must fit into the current CEBAF tunnel while allowing for personnel and equipment access. They must also be flexible enough to accommodate the beam under realistic operational conditions and fluctuations. The constraints on the system are highly restrictive, complicating the design. This document will describe the current state of the design and indicate the work remaining for a complete conceptual design.
Paper: THPC39
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPC39
About: Received: 14 May 2024 — Revised: 18 May 2024 — Accepted: 18 May 2024 — Issue date: 01 Jul 2024
THPC44
Broadband impedance induced heating proxy for operation at higher total current at SIRIUS
3090
SIRIUS, a brazilian 4th generation synchrotron light source, currently operates in top-up mode at 100mA in uniform fill. The main limiting factor for reaching higher currents is the temporary RF system in use. It is comprised of one PETRA 7-Cell cavity and two solid state amplifier towers that combined provide at most 120kW of power. By mid 2024, two superconducting RF cavities will replace the current cavity and two amplifier towers will be added to the system, allowing operation at higher currents. The design current of SIRIUS storage ring is 350mA, which can only be achieved once a third harmonic cavity is installed to lengthen the bunches to avoid excessive wake-induced heating of sensitive components. However, the installation of such cavity is not foreseen in the near future, which raises the question of which is the maximum current in uniform fill SIRIUS can be operated. This work will present some theoretical and experimental studies carried out to answer this question.
Paper: THPC44
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPC44
About: Received: 15 May 2024 — Revised: 17 May 2024 — Accepted: 18 May 2024 — Issue date: 01 Jul 2024
THPC55
Beam-cavity interaction in the CERN PS 80 MHz RF systems
3132
The 40 MHz and 80 MHz Radio Frequency (RF) systems in the CERN Proton Synchrotron (PS) are required to perform non-adiabatic bunch shortening before beam ejection. This manipulation allows to fit the bunches into the short RF buckets of the 200 MHz Super Proton Synchrotron (SPS). Although the impedance of the cavities is strongly reduced by feedback, the detailed understanding of the beam-cavity interaction is essential to evaluate their impact on the beam. This contribution focuses on the impedance characterization of the 80 MHz RF systems to describe how the RF amplification chain behaves as a function of beam current changes. Complementary measurement techniques, both beam and RF-based, were adopted. The results of the different measurements show good agreement. The aim is to study and predict possible beam quality degradation at beam intensities required by the High Luminosity LHC (HL-LHC), as well as to propose future consolidation to the high-frequency RF systems in the PS.
Paper: THPC55
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPC55
About: Received: 03 May 2024 — Revised: 22 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
THPC67
Updated analysis of beam halo measurements in LHC Run 2 and Run 3
3175
Measurements of the transverse beam halo in the Large Hadron Collider (LHC) provide crucial input for the performance evaluation of the collimation configuration in the High-Luminosity LHC (HL-LHC) era. Such measurements are carried out in various phases of the LHC operational cycle by scraping the beam with movable collimators. Understanding the halo population and halo formation mechanisms is crucial for optimising accelerator performance. Analysis of collimator scan data allows the evaluation of future needs for active halo depletion mechanisms at the HL-LHC, or other ways of mitigating halo-related risks to machine availability and protection. This contribution analyses the LHC Run 2 (2015-2018) and Run 3 (started in 2022) measurements using measured bunch-by-bunch beam intensity data. Different beam parameters are explored by profiting from upgraded beam parameters in the LHC injector complex.
Paper: THPC67
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPC67
About: Received: 13 May 2024 — Revised: 22 May 2024 — Accepted: 22 May 2024 — Issue date: 01 Jul 2024
THPC70
GSI electron lens for space charge compensation
3186
The electron lens for space charge compensation is an R&D project to increase the primary beam intensity and thus the accelerator efficiency of SIS18 and eventually SIS100 for FAIR operation. As a first step, the principle of space charge compensation will be demonstrated in SIS18 with a single lens, aiming at a tune shift of 0.1 for several ion species. However, the design should also be compatible with the SIS100. Following the conceptual design studies, a technical design of the electron lens has been prepared and the main components of the electron lens are currently under development. This contribution gives an overview of the development of the electron lens, with particular emphasis on the main lens components and the studies carried out on the dynamics of the ion beam.
Paper: THPC70
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPC70
About: Received: 15 May 2024 — Revised: 19 May 2024 — Accepted: 19 May 2024 — Issue date: 01 Jul 2024
THPC71
Minimizing space charge tune spread and increasing beam quality parameters with circular modes
3190
Space charge has been a limiting effect for low energy accelerators inducing emittance growth and tune spread. Tune shift and tune spread parameters are important for avoiding resonances, which limits intensity of the beam. Circular modes are round beams with intrinsic flatness that are generated through strong coupling, where intrinsic flatness can be transformed to real plane flatness through decoupling. It is understood that flat beams increase the quality parameters of a beam due to one of the plane emittances being smaller than the other plane since luminosity and beam brightness depend inversely on the beam emittances. We show that circular mode beams manifest smaller space charge tune spread compared to uncorrelated round beams, which allows better systematic control of operating point of the beam. Minimized tune spread allows flexible operating points on the tune map. We also dedicate current and intrinsic flatness ratio limits on circular modes, which increase quality parameters without detrimental effects on the emittance increase.
Paper: THPC71
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPC71
About: Received: 15 May 2024 — Revised: 21 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
THPC83
Test of parallel beam-based alignment at NSLS-II
3237
Misalignment of magnets in the storage rings causes trajectory deviation when the beam traverses through magnets, resulting in the degraded performance of linear optics and nonlinear dynamics. The beam-based alignment (BBA) technique is commonly used to steer the beam passing through the centers of magnets. Recently, a new method has been developed to determine the centers of multiple magnets simultaneously [1]. In this paper, the test of this fast BBA method at NSLS-II is presented.
Paper: THPC83
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPC83
About: Received: 15 May 2024 — Revised: 19 May 2024 — Accepted: 22 May 2024 — Issue date: 01 Jul 2024
THPG04
RF and multipactor analysis for the CARIE RF photoinjector with a photocathode insert
3251
At Los Alamos National Laboratory (LANL), we developed a 1.6-cell C-band RF photoinjector for the Cathodes And Radiofrequency Interactions in Extremes (CARIE) project. The injector will be used to study the behavior of advanced photocathode materials under very high RF gradients. The photocathodes will be prepared with an INFN-style photocathode plug, compatible with the plugs used by other institutions. This presentation will report the RF design of the photoinjector with distributed coupling and RF field symmetrization. Beam physics simulations show that symmetrized RF fields in the vicinity of the beam axis are essential for minimizing the normalized emittances for a 250-pC electron bunch. We will also present the design for the photocathode insertion and the analysis of the challenges related to reducing the peak electric fields, multipactor suppression, and resonant frequency tuning by fine adjustment of the plug position.
Paper: THPG04
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPG04
About: Received: 14 May 2024 — Revised: 16 May 2024 — Accepted: 17 May 2024 — Issue date: 01 Jul 2024
THPG14
Automation upgrade of the CXLS photoinjector
3275
The automation upgrade of the photoinjector for the Compact X-Ray Light Source (CXLS) at Arizona State University is described. As the accelerator vault of the CXLS is only 10 meters long, the photoinjector drive laser is located in an enclosure inside the vault. Since ionizing radiation is present in this room during operations, it necessitates remote control of all devices used to optimize the laser spot. This includes multiple shutters, Galil motors, picomotors, a mirror flipper, LEDs, and remote lens controllers. To actuate these devices, a GUI was created with the use of MATLAB AppDesigner which communicates with the hardware through EPICS (Experimental Physics and Industrial Control System). Challenges with this GUI are described, along with the team’s efforts to finalize the control software. After these upgrades, the photoinjector laser characteristics can be adjusted remotely during operation and changes to the drive laser’s position, shape, and intensity can be made without interrupting beam time.
Paper: THPG14
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPG14
About: Received: 15 May 2024 — Revised: 19 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
THPG17
Prototype control system for the Low Energy Branch ion beamline
3285
At the tandem ion accelerator laboratory of the Jožef Stefan Institute (JSI) in Ljubljana, Slovenia we are developing a control system for the Low Energy Branch (LEB) ion beamline. This activity is ongoing simultaneously with the hardware construction of the ion beamline branch dedicated to the research with low-energy ion beams with energies up to 30 keV. The LEB instrumentation is categorized into: a) Ion sources, b) Ion beam transport optics, and c) Accessories, including specialized detector systems and devices, used to prepare and maintain optimal experimental conditions. Therefore, key functionalities of the control system include the control of devices like vacuum pumps, power supplies, etc., data acquisition from sensors and detector systems, and ensuring reliable autonomous operation for high-precision physics experiments [1]. The control system will be implemented within the Experimental Physics and Industrial Control System (EPICS) environment [2], providing us with the tools required to develop a comprehensive and scalable control system. In this work, we present a block scheme, a device list, the prototype control system architecture of a minimal control system prototype currently operational in our laboratory.
Paper: THPG17
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPG17
About: Received: 15 May 2024 — Revised: 19 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
THPG18
Cost-effective asset management for accelerator control systems: design and implementation for the ALS-U controls system
3289
This paper presents a cost-effective asset management system (AMS) designed to optimize the workflow of the accelerator control system for the Advanced Light Source Upgrade (ALS-U) project at LBNL. The AMS stores all essential information about equipment, including location, owner, hardware details, and firmware versions. Its user-friendly interface provides consistent access throughout the equipment lifecycle, from quality assurance to installation, through label printing, QR codes, and the Web application. By streamlining workflows and improving data consistency, the AMS contributes significantly to the efficiency and success of the ALS-U project.
Paper: THPG18
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPG18
About: Received: 15 May 2024 — Revised: 18 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
THPG22
Implementation of EPU56 control system at the Taiwan Photon Source
3301
The elliptically polarized undulator with a period length of 56 mm, called EPU56, is part of the Taiwan Photon Source (TPS) phase-III beamline project. Its control system is built within the EPICS framework using motion controllers and EtherCAT. The control systems of EPU56 include a safety interlock system, which automatically stops movement based on limit switches, torque limit switches,emergency stop button, and readings from the enclosed linear optical encoder. In addition, the control system offers settings for adjusting the correction magnets' power supply and employs optical absolute encoder motors to control the movement of the Gap and Phase. In order to maintain stability during movement, PID control is applied to the motion process by the motion controller. To further enhance precision, the system also employs an integrator limit within the motion controller for additional adjustments. This paper describes the development of the control system and the enhancements made to the insertion device movement process.
Paper: THPG22
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPG22
About: Received: 15 May 2024 — Revised: 20 May 2024 — Accepted: 20 May 2024 — Issue date: 01 Jul 2024
THPG24
Real-time data acquisition with CompactPCI serial platform at PSI
3308
Data acquisition (DAQ) is an ubiquitous feature in modern particle accelerator measurement and control systems. At the Paul Scherrer Institut (PSI), a next generation of electronic devices is being designed to meet the demands of upcoming renewal of facilities. The new developments utilize the CompactPCI Serial (CPCI-S.0) platform, and will cover a diverse set of applications, including Low Level Radio Frequency (LLRF), Longitudinal Beam Loss Monitoring (LBLM), and Filling Pattern Monitoring (FPM) systems. Careful design considerations and selection of an optimal architecture are crucial to fulfill a variety of DAQ requirements such as maximum frequency of acquisition, size of the data and different modes of triggering. In this contribution, we focus on the real-time DAQ implementations utilizing a multiprocessor system on chip (MPSoC) technology. We review the IP components developed in-house at PSI that provide the DAQ functionality. We demonstrate, that by reusing the IP components development, prototyping and testing of applications requiring the DAQ are accelerated.
Paper: THPG24
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPG24
About: Received: 14 May 2024 — Revised: 18 May 2024 — Accepted: 18 May 2024 — Issue date: 01 Jul 2024
THPG29
A multi-variable approach to mid-ranging control for unified operation of fast and slow correctors in fast orbit feedback system
3314
Advanced Photon Source Upgrade (APS-U) Fast Orbit Feedback (FOFB) system uses 160 fast and 160 slow corrector magnets to stabilize orbit measured at 560 Beam Position Monitors (BPM). We plan to operate both fast and slow correctors in a unified feedback algorithm at 22 kHz correction rate. Mid-ranging control is a proven approach for feedback systems with two manipulated inputs each exerting distinct dynamic effects to regulate a single output. This method resets the fast input to its chosen DC setpoint and proves beneficial when cost of fast input is more than the slower one. Unified operation of fast and slow correctors is a fitting application to mid-ranging concept which is well founded for two input one output systems. In this work, based on the cross-directional nature of the FOFB system we developed a multi-variable approach to mid-ranging control. It can be applied to FOFB with multiple fast and slow correctors, and multiple BPMs. Performance of proposed scheme is tested in simulations with APS-U FOFB prototype model in MATLAB. The feedback loop with fast and slow correctors is stable with mid-ranging algorithm, and the fast corrector drives effectively tracked setpoints.
Paper: THPG29
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPG29
About: Received: 16 May 2024 — Revised: 21 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
THPG32
BPM feedback for LLRF energy and phase regulation in charge stripping beamlines
3326
Charge stripping is inherent for high power ion accelerators such as the FRIB LINAC. However, at high power, strippers require motion to prolong the operational life of the stripping media, or by flowing a liquid Lithium film. The charge stripping process introduces energy losses that vary with the actual Lithium film thickness, which can result in observable beam losses along the tuned beamline at high on-target beam power, above ~100 kW, if not adequately mitigated. BPM phase feedback is used in real-time to compensate for these effects, controlling upstream RF cavities in order to maintain a constant beam energy and phase post-stripper, which significantly reduces beam energy fluctuations.
Paper: THPG32
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPG32
About: Received: 15 May 2024 — Revised: 18 May 2024 — Accepted: 18 May 2024 — Issue date: 01 Jul 2024
THPG36
Continuous position estimation for the full remote alignment system of the High Luminosity LHC upgrade
3337
The Full Remote Alignment System (FRAS) is an alignment system remotely controlled and monitored that comprises almost one thousand permanent sensors distributed along the 200 meters of equipment that will be installed in the frame of the High Luminosity LHC (HL-LHC) project on either side of the ATLAS and CMS detectors. The sensors, along with their electronics and a system of motorized actuators, will be used to adjust the relative positions of the components remotely, in real time, with no human intervention needed in the irradiated environment of the tunnel. In this contribution we describe the design and the implementation of the position estimation algorithm which is a core-component of the FRAS. This algorithm will process the data provided by all the sensors to determine exact positions and orientations of the associated components in real-time. The position estimation module is designed as a reusable C++ library and builds on the existing CERN LGC, a modular least-square software. It will be fully integrated into the FRAS software stack and is entirely file-less during operation. In this paper we will demonstrate its performance in a realistic case study and showcase its ability to provide position updates on a much higher frequency than the required 1 Hz.
Paper: THPG36
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPG36
About: Received: 15 May 2024 — Revised: 17 May 2024 — Accepted: 18 May 2024 — Issue date: 01 Jul 2024
THPG42
Radiation levels in the LHC tunnel and impact on electronics during the 2023 Pb ion run
3355
The 2023 operation of the Large Hadron Collider (LHC) at CERN included a one-month-long run with fully stripped Pb ion beams, marking the first heavy-ion run since 2018, and delivering Pb ion collisions at an unprecedented center-of-mass energy of 5.36 TeV per nucleon pair. During this period, the radiation fields in the LHC tunnel have been measured by means of different radiation monitors, including Beam Loss Monitors (BLMs), RadMons, and distributed optical fiber dosimeters, with the primary goal of quantifying the radiation exposure of electronic systems. The radiation levels are driven by the Bound Free Pair Production (BFPP) and Electromagnetic Dissociation (EMD) processes taking place in all four interaction points, yielding significant radiation peaks in the Dispersion Suppressor (DS) regions of the tunnel. An overview of the radiation levels is presented in this contribution, with a special focus on the Insertion Region 2 (IR2) hosting the ALICE experiment, where a new collimator (TCLD) has been installed specifically for the ion run. The impact of radiation on the electronic systems and on the LHC availability during the run will also be discussed.
Paper: THPG42
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPG42
About: Received: 08 May 2024 — Revised: 22 May 2024 — Accepted: 22 May 2024 — Issue date: 01 Jul 2024
THPG50
Lifetime studies of magnet protection systems for the Large Hadron Collider at CERN
3378
In the architecture of the protection of the superconducting magnets of the Large Hadron Collider (LHC), systems such as Quench Heater Discharge Power Supplies (HDS), Local Protection Interface Module (LIM), Linear Redundant Power Supplies (LPR), and Power Packs (LPUS) are crucial. Thousands of these devices, some in operation since 2007, directly impact LHC’s availability and reliability. This paper delves into comprehensive lifetime studies on these critical systems. The methodology involves estimating their remaining operational lifespan through detailed analyses of failure modes, assessing electronic component criticality, accelerated aging of electrolytic capacitors, inspections, and irradiation tests at both component and system levels. The study concludes by presenting essential findings, including the estimated remaining lifetime of each equipment. Additionally, the paper recommends future developments to enhance system robustness, offering valuable insights for maximizing the longevity of these critical devices. This research significantly contributes to ensuring the sustained reliability and performance of the LHC's magnet protection systems.
Paper: THPG50
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPG50
About: Received: 15 May 2024 — Revised: 22 May 2024 — Accepted: 22 May 2024 — Issue date: 01 Jul 2024
THPG51
Design, manufacturing and validation of the CLIQ units for the protection of superconducting magnets for the High-Luminosity LHC project at CERN
3382
The novel Coupling-Loss-Induced-Quench (CLIQ) concept will be part of the quench protection system of the High Luminosity Large Hadron Collider (HL-LHC) Inner Triplet superconducting magnets at CERN. Several units of two distinct CLIQ prototype variants were produced to validate the CLIQ novel protection concept and define the system parameters for the required performance. Subsequently, these units were further enhanced by introducing additional redundancy, advanced monitoring systems, and improved safety features. These improvements culminated in the development of the third and final version. This paper provides insights into the evolution from prototypes to the final version to be installed in the machine, shedding light on the outcomes of comprehensive safety and electromagnetic compatibility (EMC) tests, coupled with extensive operational assessments.
Paper: THPG51
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPG51
About: Received: 15 May 2024 — Revised: 21 May 2024 — Accepted: 22 May 2024 — Issue date: 01 Jul 2024
THPG52
Design, manufacturing and validation of the new quench heater discharge power supplies for the protection of superconducting magnets for the High-Luminosity LHC Project at CERN
3386
The Quench Heater Discharge Power Supplies (HDS) are magnet protection devices installed in the Large Hadron Collider (LHC) that, upon detection of a magnet quench, release energy into the copper-plated stainless-steel strip heaters, inducing a resistive transition all along the superconducting coils. Such a distributed internal heating ensures an even energy dissipation across the entire volume, preventing local overheating and magnet damage. Over 6000 HDS units have been operational in the LHC tunnel since 2007. The new HDS design for protection of the High Luminosity LHC (HL-LHC) Inner Triplet magnets, to be installed in the Long Shutdown starting in 2026, calls for a more advanced design with up-to-date components resulting in a higher reliability of the HDS units. Several HDS prototypes were produced at CERN, eventually culminating in the development of the HL-LHC HDS version to be installed in the accelerator. This paper describes the design of the upgraded HDS units and the comprehensive safety and electromagnetic compatibility (EMC) tests, coupled with extensive operational tests, including irradiation tests, that have been conducted.
Paper: THPG52
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPG52
About: Received: 15 May 2024 — Revised: 20 May 2024 — Accepted: 20 May 2024 — Issue date: 01 Jul 2024
THPG58
Radiation levels from a beam gas curtain instrument at the LHC at CERN
3393
A prototype Beam Gas Curtain (BGC) monitor was installed at the Large Hadron Collider (LHC) at CERN to provide 2D images of the transverse beam profile during the ongoing Run 3 (2022 to date) and in view of the High Luminosity LHC upgrade (HL-LHC). By design, the BGC operation generates collisions between the beam particles and an injected gas jet proportionally to the beam intensity and the gas density, possibly causing radiation-induced issues to the downstream LHC equipment. In this work, the radiation showers from the BGC are characterized using measured data from different LHC radiation monitors during the Run 3 BGC operation, along with Monte Carlo simulations with the FLUKA code. Finally, predictions of the expected radiation showers during the operation of the BGC in the HL-LHC era are discussed.
Paper: THPG58
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPG58
About: Received: 10 May 2024 — Revised: 21 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
THPG59
Testing aspects of the CERN beam interlock system prior to installation in the accelerator
3397
The Beam Interlock System (BIS) is the backbone of the machine protection system throughout the accelerator complex at CERN, from LINAC4 to the LHC. After 15 years of flawless operation, a new version of the BIS is currently being produced and will be installed in the LHC, SPS and North Area during CERN’s Long Shutdown 3, planned to start in 2026. Overall, more than 3,000 Printed Circuit Boards will be produced and assembled outside CERN. In addition, more than 120,000 lines of firmware and supporting scripts are written to implement the critical and monitoring functionalities of the BIS. Both hardware and firmware need to be thoroughly tested before installation and operation to guarantee the high levels of reliability and availability required by the operation of the accelerators. In this paper we present the testing methodology including the development of dedicated testbeds for hardware validation, the use of comprehensive simulation and continuous integration for firmware development, and the implementation of automated tests for system-level functional validation.
Paper: THPG59
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPG59
About: Received: 06 May 2024 — Revised: 17 May 2024 — Accepted: 17 May 2024 — Issue date: 01 Jul 2024
THPG61
An approachable beam loss monitor configuration and operation tool for FRIB
3405
The folded Linear Accelerator (linac) at the Facility for Rare Isotope Beams (FRIB) presents many challenges to effectively utilizing beam loss monitors (BLMs) for machine protection. Dozens of ion chambers and neutron detectors are installed at various locations in the linac tunnel to monitor radiation from beam losses. Each device must be configured with thresholds to meet machine protection requirements for an array of beam destinations, ion species, beam energies, beam power, and response times. This presents an extremely large configuration space with numerous use-cases and beam modes to account for. We present a largely automated tool to effectively manage BLM thresholds that requires minimal input from operators.
Paper: THPG61
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPG61
About: Received: 15 May 2024 — Revised: 18 May 2024 — Accepted: 18 May 2024 — Issue date: 01 Jul 2024
THPG62
FRIB target thermal image processing for accurate temperature mapping
3409
The FRIB carbon disc target receives the primary beam at high power and produces rare isotope fragments. To avoid damaging the carbon disc target, it is rotated at 500 RPM and cooled. If these thermal management mechanisms fail, local temperatures on the target can increase to the point of material sublimation and structural failure. A thermal imaging camera was temperature calibrated and installed for the purpose of monitoring the target temperature map in real time. Various image processing strategies were deployed to improve the accuracy and usefulness of the resulting image. Processing stages include conversion from intensity to temperature, median filtering to remove dead pixels, and flat field correction to compensate for vignetting and edge effects.
Paper: THPG62
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPG62
About: Received: 15 May 2024 — Revised: 21 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
THPG63
FPGA design of FRIB chopper monitor system
3413
In FRIB we use chopper in the low energy beam line for beam power controls. As appropriate functioning of chopper is critical for both beam operation and machine protection, an FPGA-based chopper monitoring system was developed to monitor its operation for fixed duty cycle operation and has been in use to support operation. The chopper monitor shuts off beam promptly at detection of a deviation of duty cycle outside tolerance. For future higher beam power operation, automatic beam power ramp modes will be required where beam duty factor is dynamically ramped up following a predetermined sequence. Recently FPGA prototype is developed to enhance the chopper monitor to accommodate one of such dynamic modes, cold start beam mode. It is a design challenge to integrate all the beam modes in one FPGA while synchronizing with external timing system pulse generator and recording the process data and failure information. Detailed FPGA design for this enhancement of chopper monitor will be discussed in this paper, followed by the test result of integrated system of chopper monitor, global timing system pulse generator, high voltage switch of chopper control and EPICS control software.
Paper: THPG63
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPG63
About: Received: 15 May 2024 — Revised: 23 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
THPG66
Machine protection system for TEX facility
3424
In the context of LATINO (Laboratory in Advanced Technologies for INnOvation) and Rome Technopole Projects founded by Regione Lazio and NextGenerationEu, and directly involved in the EuPRAXIA@SPARC_Lab flagship project, a testing facility for X-band (TEX) has been established at the Frascati National Laboratories of INFN. TEX is dedicated to the examination of radiofrequency X/C-band, aiming to develop and test the technologies and systems of a particle accelerator operating under such conditions. Given the complex nature of such a system and the advancement of technology to the forefront of the state of the art, it is imperative to have an advanced Machine Protection System (MPS) characterized by high reliability, availability, and safety, in accordance with IEC-61508 standards. Currently in development is a prototype MPS designed to autonomously initiate procedures to control operations and avert anomalies. An EPICS supervisor oversees the management of all devices and monitoring connected subsystems. Additionally, a real-time interlock system, based on distributed FPGA, is employed to swiftly respond to vacuum and RF systems during the next RF pulse.
Paper: THPG66
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPG66
About: Received: 15 May 2024 — Revised: 22 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
THPG69
Improvements of longitudinal stability with LLRF optimization at SIRIUS
3435
SIRIUS is a 4th generation synchrotron light source built and operated by the Brazilian Synchrotron Light Laboratory (LNLS). Recently, investigations of noise sources and the storage ring RF plant identification enabled a fine-tuning of the Digital Low-Level Radio Frequency (DLLRF) parameters. This paper presents the main improvements implemented, which include the mitigation of 60Hz noise from the LLRF Front End and the optimization of the control system parameters. Optimizations in the machine were based on an adjusted model of the SIRIUS storage ring RF plant. Tests with the model's parameters showed that the system's stability was strongly dependent on phase shifts introduced by nonlinearities from the high power RF sources. The new parameters significantly improved the control performance, increasing the bandwidth of the system and reducing longitudinal oscillations. BPM (Beam Position Monitor) and BbB (Bunch-by-Bunch) systems were employed to quantify longitudinal beam stability improvements.
Paper: THPG69
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPG69
About: Received: 14 May 2024 — Revised: 20 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
THPG70
Canadian Light Source developments of the ALBA/CLS DLLRF system
3439
Located in Saskatoon, Saskatchewan, Canada, the Canadian Light Source (CLS) has been operation since 2003. CLS is a 3rd generation Synchrotron Light Source operating at 2.9GeV. The CLS Booster RF system uses a 100 kW, 500 MHz solid-state power amplifier to power two 5-cell “PETRA” cavities. Recently ALBA and CLS collaborated to commission a CLS-constructed version of the ALBA Digital Low-Level RF system in the CLS Booster ring RF system to replace the aging analog low-level RF system. Changes were required to address differing configuration and requirements between the CLS and ALBA RF systems. Challenges and opportunities for system machine safety, reliability, and performance improvements identified during and after commissioning have been addressed. Hardware configuration changes were implemented. Additional hardware devices have been produced and incorporated to streamline interfacing and to mitigate some risks.
Paper: THPG70
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPG70
About: Received: 15 May 2024 — Revised: 20 May 2024 — Accepted: 20 May 2024 — Issue date: 01 Jul 2024
THPG71
Commissioning of the digital LLRF system at the KEK Photon Factory 2.5 GeV ring
3442
In 2023, the KEK-PF 2.5 GeV ring LLRF system was replaced from a conventional analog to an FPGA-based digital system. The hardware and software of our digital LLRF system were developed by customizing the LLRF technologies established at the SPring-8 and J-PARC. In our system, we adopted the non-IQ direct sampling method for RF detection. We set the sampling frequency at 8/13 (307.75 MHz) of the RF frequency, where the denominator (13) is the divisor of the harmonic number (312) of the storage ring. This allows us to detect the transient variation of the cavity voltage that is synchronized with the beam revolution. To compensate this voltage variation, we plan to implement a feedforward technique. These functions will be useful to improve the bunch lengthening performance in a double RF system for KEK future synchrotron light source. The new digital LLRF system has been already installed and used for the user operation. At the nominal beam current of 450 mA, the variation of the cavity voltage amplitude and phase were within ±0.06% and ±0.06°, respectively. In this presentation, we introduce the details of our new system and report on the commissioning results.
Paper: THPG71
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPG71
About: Received: 10 May 2024 — Revised: 22 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
THPG76
Improved beam loss accounting with fast data acquisition (DAQ) chassis
3446
Identifying the source of beam loss events in the CEBAF accelerator can be a challenging task. Determining whether an RF cavity with an unannounced gradient or phase transient is the culprit would be a valuable tool for operations staff in addressing recurring beam loss incidents. A prototype offline system was developed in the fall of 2022, utilizing a dispersive beam position monitor (BPM) and the existing switched electrode electronics BPM hardware. A commercial off-the-shelf data acquisition (DAQ) system was employed to capture BPM wire signals at a sample rate of 20 kS/s. The system was triggered by the fast shutdown signal, which disables the beam at the injector. Analysis of beam position and energy variation before a beam loss event was used to determine if the beam loss event was associated with an energy transient. The prototype system, implemented using National Instruments hardware and LabVIEW software, relied on a software trigger. Manual post-processing was required to ascertain whether the fault was due to an un-tripped cavity with a gradient or phase transient. This work presents a production-quality system that utilizes the same data acquisition hardware developed and installed in CEBAF to monitor the time domain RF control signals in the legacy analog RF systems. As the new system employs a hardware trigger, developing tools to automatically identify faults linked to energy transients unrelated to cavity faults will be straightforward.
Paper: THPG76
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPG76
About: Received: 14 May 2024 — Revised: 17 May 2024 — Accepted: 17 May 2024 — Issue date: 01 Jul 2024
THPG81
HPSim simulation of the highly bunched WNR beam at LANSCE
3457
The linac at the Los Alamos Neutron Science Center (LANSCE) provides beam to five user facilities with various beam energy and timing patterns. While the other four facilities have the same 201.25-MHz micro-bunch structure created by a pre-buncher and main-buncher pair, the Weapon Neutron Research (WNR) requires significantly higher charge per micro-bunch. This is achieved via adding a low frequency buncher at 16.77 MHz to the Low Energy Beam Transport. Such highly bunched micro-bunches create several challenges in operation and remain a critical capability to maintain for the LANSCE Modernization Project. We will demonstrate the HPSim simulation of the WNR beam through the LANSCE linac as a tool to address these issues in the future.
Paper: THPG81
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPG81
About: Received: 14 May 2024 — Revised: 20 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
THPG82
Using a particle-in-cell model for accelerator control room applications
3461
Many accelerator control rooms rely on envelope models to simulate beam dynamics because they are fast and accurate at tracking the beam core. Particle-in-Cell (PIC) models, however, can track particles inside and outside the core and, with the improvements of computers, are now fast enough to be used in control rooms. The Spallation Neutron Source (SNS) at Oak Ridge National Laboratory is currently developing a tool to use a Particle-in-Cell model for control room applications. This report covers the progress so far and the future goals of using PyORBIT, a Particle-in-Cell simulation model, in the SNS control room.
Paper: THPG82
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPG82
About: Received: 15 May 2024 — Revised: 19 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
THPG84
3D visualization and analysis of neutron scattering data in the control room
3465
Neutron scattering experiments have undergone significant technological development through large area detectors with concurrent enhancements in neutron transport and electronic functionality. Data collected for neutron events include detector pixel location in 3D, time and associated metadata, such as sample orientation and environmental conditions. Working with single-crystal diffraction data we are developing both interactive and automated 3D analysis of neutron data by leveraging NVIDIA’s Omniverse technology. We have implemented machine learning techniques to automatically identify Bragg peaks and separate them from diffuse backgrounds and analyze the crystalline lattice parameters for further analysis. A novel CNN architecture has been developed to identify anomalous background from detector instrumentation for dynamical cleaning of measurements. Our approach allows scientists to visualize and analyze data in real-time from a conventional browser, which promises to improve experimental operations and enable new science. We have deployed a cloud based server, leveraging Sirepo technology, to make these capabilities available to beamline users in the control room.
Paper: THPG84
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPG84
About: Received: 15 May 2024 — Revised: 04 Jun 2024 — Accepted: 04 Jun 2024 — Issue date: 01 Jul 2024
THPR06
Update on automated RF-conditioning utilizing machine learning
3488
The conditioning of room temperature cavities is an exhausting process. To prevent damage to the cavity and auxiliary equipment, this potentially long process needs constant supervision or extensive safety precautions. Additionally, the unpredictability of every new conditioning makes the development of effective classical algorithms difficult. To reduce the workload for everyone involved and to increase the efficiency of the conditioning process, it was decided to develop a machine learning algorithm with the goal of fully automated conditioning in mind. To reach this goal, it is planned to train the model on the data of already conducted conditionings of room temperature cavities, a virtual cavity and several more conditionings to be conducted soon. In this paper, the status of development, problems and challenges as well as the planned future progression shall be summarized.
Paper: THPR06
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPR06
About: Received: 13 May 2024 — Revised: 17 May 2024 — Accepted: 22 May 2024 — Issue date: 01 Jul 2024
THPR08
Improvements to 4-rod RFQs with additive manufacturing processes
3494
The institute of applied physics (IAP), university of Frankfurt, has been working for years on the development of increasingly powerful 4-Rod RFQ accelerators for hadron acceleration. The need for such accelerators has increased significantly in the recent past, as accelerator-driven neutron sources are becoming increasingly important following the closure of various test reactors. High beam currents, particle energies and operational stability are often required from those LINACs. In order to meet these requirements, the copper structure of the RFQ is to be manufactured using a new type of pure copper 3D printing in order to be able to introduce optimized cooling channels inside the copper parts. Comprehensive multiphysics simulations with ansys, cst and autodesk CFD will first be carried out to evaluate the operational stability and performance. In addition, it will be clarified whether the printed copper fulfills the necessary vacuum and conductivity requirements after CNC processing, or whether galvanic copper plating should be carried out.
Paper: THPR08
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPR08
About: Received: 15 May 2024 — Revised: 24 May 2024 — Accepted: 24 May 2024 — Issue date: 01 Jul 2024
THPR09
High-power RF conditioning and 700 keV beam commissioning of the revised RFQ for the Frankfurt Neutron Source
3497
We report the successful high power RF conditioning of the revised 175 MHz FRANZ RFQ up to 80 kW CW, as well as successful beam commissioning up to 700 keV in pulsed operation. After a revision of the RFQ electrodes, the RFQ accelerates protons from 60 keV to 700 keV. The Frankfurt Neutron Source FRANZ will be a compact accelerator driven neutron source utilizing the 7Li(p,n)7Be reaction with a 2 MeV proton beam.
Paper: THPR09
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPR09
About: Received: 14 May 2024 — Revised: 21 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
THPR10
RF conditioning of an IH-DTL cavity made using additive manufacturing
3501
Additive manufacturing ("AM") has become a powerful tool for rapid prototyping and manufacturing of complex geometries. A 433 MHz IH-DTL cavity has been constructed to act as a proof of concept for direct additive manufacturing of linac components. In this case, the internal drift tube structure has been produced from 1.4404 stainless steel, as well as pure copper using AM. We present the most recent results of vacuum, low level RF, as well as RF conditioning of the cavity.
Paper: THPR10
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPR10
About: Received: 14 May 2024 — Revised: 20 May 2024 — Accepted: 20 May 2024 — Issue date: 01 Jul 2024
THPR12
Simultaneous acceleration of multiple beams in novel LANSCE front end
3505
We present the 100 MeV injector design for the LANSCE Accelerator Facility, which is designed to replace the existing 750-keV Cockcroft-Walton-columns-based injector. This new Front End includes two independent low-energy transports for H+ and H- beams merging at the entrance of a single RFQ, with the subsequent acceleration of particles in the new Drift Tube Linac. The challenge of this design is associated with the necessity of simultaneous acceleration of protons and H- ions with multiple beam flavors in a single RFQ and DTL. The LANSCE operation regime provides simultaneous delivery of beams to five experimental areas, with a forecasted increase in the number of targets in the future. Each beam is characterized by a unique time structure, pulse length, emittance, and charge per bunch. The paper presents the details of this design and injector parameters.
Paper: THPR12
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPR12
About: Received: 11 May 2024 — Revised: 20 May 2024 — Accepted: 20 May 2024 — Issue date: 01 Jul 2024
THPR13
Conditioning of rod-style RFQ in support of LANSCE front-end upgrade
3508
The Los Alamos Neutron Science Center (LANSCE) front-end injection scheme requires an upgrade to a Radio-Frequency Quadrupole (RFQ) in order to replace the obsolete Cockroft-Waltons used in present operation. A test stand using a rod-style RFQ is under development in support of this upgrade, and conditioning of the RFQ to the expected peak and average power levels was completed to ensure its feasibility. The RFQ conditioning also revealed thermal issues with the RF power coupler and issues in managing the power reflected from the RFQ. These issues and their mitigation will be discussed in light of the capability of the test stand, and future plans will also be discussed.
Paper: THPR13
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPR13
About: Received: 15 May 2024 — Revised: 21 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
THPR15
Simple estimate, detailed computer simulation and measurement of the transverse kick in the SLAC accelerating structure
3516
We discuss the result of calculation and measurement of the transverse kick in the SLAC accelerating section in a single bunch and multi-bunch regimes. We present a simple estimate, which can be used in practical situations.
Paper: THPR15
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPR15
About: Received: 14 May 2024 — Revised: 18 May 2024 — Accepted: 18 May 2024 — Issue date: 01 Jul 2024
THPR16
Design of a spin rotator for the ISIS Super-MuSR beamline
3520
The spin rotators (SR) are DC electromagnetic devices that produce a homogeneous magnetic field to rotate the spin of the muons in flight, which is counterbalanced by a matched perpendicular electric field to avoid the bending of the muon beam trajectory. Two identical SR will be used in the new Super-MuSR beamline to rotate the muon spin by up to 34º per device relative to the beam direction, enabling higher transverse field muon measurements and other experiments not currently possible in the present ISIS MuSR beamline. The fundamental electromagnetic (EM) design of the SR is presented in this paper, both for the magnet and the high voltage vessel. The optimization of the electric and magnetic fields shape and strength is presented including fundamental hand calculations, 2D/3D models and particle tracking simulations. The high voltage feedthroughs and the electrode insulating supports were thoroughly designed to reduce the breakdown probability. A sensitivity study was also developed to estimate the manufacturing tolerances, but it is not presented in this paper.
Paper: THPR16
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPR16
About: Received: 30 Apr 2024 — Revised: 17 May 2024 — Accepted: 17 May 2024 — Issue date: 01 Jul 2024
THPR18
Mechanical design of a QWR cavity for the new ISIS MEBT
3528
The Quarter Wave Resonator (QWR) is a longitudinal bunching cavity for the MEBT section of the Pre-injector Upgrade project at ISIS. Four cavities are required with at least one functional spare. The production of a full scale prototype is discussed here. Three main manufacturing challenges were encountered as follows: the tight manufacturing tolerances of the stainless steel tank, most noticeably the 80 µm tolerance along the length of the 370 mm bore; the 50 µm ± 10 µm copper plating layer on the inside of the complex geometry cavity; and the brazing of the copper lid to a long (280 mm) stem with the use of a jig, to achieve a tight precision in the length inside the cavity. Trials for all these have been conducted before being accurately assembled with a CMM, with lessons learnt and the final solutions presented.
Paper: THPR18
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPR18
About: Received: 02 May 2024 — Revised: 17 May 2024 — Accepted: 17 May 2024 — Issue date: 01 Jul 2024
THPR24
Operation status of FRIB wedge systems and plan for power ramp up
3545
At the Facility for Rare Isotope Beams (FRIB) Advanced Rare Isotope Separator (ARIS), wedges are critical devices to achieve rare isotope beam production. Different ions experience a different amount of slowing down by the wedges, which leads to a spatial separation of ion species and enables separation/purification of the secondary isotope beam. As of December 2023, wedge systems have successfully supported FRIB commissioning for over 4,000 hours. Nearly 60 unique wedges were utilized which were implemented during 15 wedge maintenance periods. Material selection, unique wedge designs for beam tuning, secondary wedge design, and diagnostic wedge design developments will be discussed in this paper. The current wedge devices will support primary beam operations to a power level of 65 kW, as evaluated by analysis. Development is underway to achieve a higher power wedge system, capable of 400 kW with full remote handling capacity. Further development plans include a variable wedge system to reduce maintenance time and increase ARIS tuning flexibility.
Paper: THPR24
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPR24
About: Received: 08 May 2024 — Revised: 18 May 2024 — Accepted: 18 May 2024 — Issue date: 01 Jul 2024
THPR25
Design automation of pre-separator wedges for FRIB advanced rare isotope separator
3549
At the Facility for Rare Isotope Beams (FRIB) unique pre-separator wedges are required for each experiment. As the number of experiments and wedges needed increases every year, reduction in design time and increase in accuracy is critical (FY23 utilized 40 unique wedges, FY24 approx. 60 are planned, and eventually 100 annually). Design automation is achieved by DriveWorksXpress, which reduced design/drafting time by 60%. A form was created with parameters (inputs) listed for each component of the wedge assembly (e.g., wedge height, wedge on axis thickness, wedge angle, etc.). The dimensions and file properties of each component are then able to reference the input values for each parameter from the form and automatically adjust the model and assembly accordingly. Automation on drawing drafting is achieved at the same time. The reduction in design time resulted in completing the design task more efficiently. A reduction in design error and human error was also observed, reducing manufacturing down time and effort required during the release process. These benefits have streamlined the mechanical design process for the pre-separator wedges.
Paper: THPR25
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPR25
About: Received: 09 May 2024 — Revised: 23 May 2024 — Accepted: 24 May 2024 — Issue date: 01 Jul 2024
THPR28
Upgrade of the PS booster-to-ISOLDE beam transfer line to facilitate an increase in proton driver energy
3552
Following the successful completion of the LHC Injectors Upgrade (LIU) project, since 2021 the Proton Synchrotron (PS) Booster has served the LHC injector chain with protons at an increased kinetic energy of 2 GeV. An upgrade of the ISOLDE (Isotope Separator On-Line DEvice) facility has long been considered to produce radioactive ion beams with a higher energy proton driver beam. A Consolidation and Improvements programme is presently underway to maintain ISOLDE’s position as a world-leading ISOL facility in the decades to come, with activities planned during the upcoming Long Shutdown 3 (LS3) (2026 - 28) and beyond. This contribution details a study to upgrade the beam line from the PS Booster to ISOLDE to operate between 1.4 and 2 GeV, and to increase the power of the proton driver in the future, assuming the replacement of the two beam dumps behind the facility’s production targets.
Paper: THPR28
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPR28
About: Received: 13 May 2024 — Revised: 19 May 2024 — Accepted: 19 May 2024 — Issue date: 01 Jul 2024
THPR29
High fidelity numerical modelling and condition monitoring applied to septum magnets at CERN
3556
The CERN Accelerator Beam Transfer group has recently launched a study to investigate the life cycles of pulsed septum magnets. The development is aiming to enhance the prediction of anomalies, leading to reduced life cycles of these beam transfer equipment. For this reason, the standard vacuum operated, direct drive septa magnet has been chosen to investigate critical design features. In the initial project phase, a so called High-Fidelity (HF) numerical simulation has been carried out, providing insight on critical components, like brazed joints, reducing the fatigue life. In parallel a dedicated test setup with state-of-the-art instrumentation has been developed, allowing to confirm the predicted system response. The novel approach for the beam transfer equipment will allow to review presently established design criteria. In a further iteration, the project is now aiming to demonstrate an anomaly detection and their prediction based on novel machine learning techniques. This paper presents the initial phase of developing the HF model, as well as the results of the instrumented magnet tests which will be compared to results from the numerical simulations.
Paper: THPR29
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPR29
About: Received: 14 May 2024 — Revised: 17 May 2024 — Accepted: 18 May 2024 — Issue date: 01 Jul 2024
THPR36
Automated anomaly detection on European XFEL klystrons
3575
High-power multi-beam klystrons represent a key component to amplify RF to generate the accelerating field of the superconducting radio frequency (SRF) cavities at European XFEL. Exchanging these high-power components takes time and effort, thus it is necessary to minimize maintenance and downtime and at the same time maximize the device's operation. In an attempt to explore the behavior of klystrons using machine learning, we completed a series of experiments on our klystrons to determine various operational modes and conduct feature extraction and dimensionality reduction to extract the most valuable information about a normal operation. To analyze recorded data we used state-of-the-art data-driven learning techniques and recognized the most promising components that might help us better understand klystron operational states and identify early on possible faults or anomalies.
Paper: THPR36
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPR36
About: Received: 16 May 2024 — Revised: 20 May 2024 — Accepted: 20 May 2024 — Issue date: 01 Jul 2024
THPR37
Towards unlocking insights from logbooks using AI
3579
Electronic logbooks contain valuable information about activities and events concerning their associated particle accelerator facilities. However, the highly technical nature of logbook entries can hinder their usability and automation. As natural language processing (NLP) continues advancing, it offers opportunities to address various challenges that logbooks present. This work explores jointly testing a tailored Retrieval Augmented Generation (RAG) model for enhancing the usability of particle accelerator logbooks at institutes like DESY, BESSY, Fermilab, BNL, SLAC, LBNL, and CERN. The RAG model uses a corpus built on logbook contributions and aims to unlock insights from these logbooks by leveraging retrieval over facility datasets, including discussion about potential multimodal sources. Our goals are to increase the FAIR-ness (findability, accessibility, interoperability, and reusability) of logbooks by exploiting their information content to streamline everyday use, enable macro-analysis for root cause analysis, and facilitate problem-solving automation.
Paper: THPR37
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPR37
About: Received: 16 May 2024 — Revised: 16 May 2024 — Accepted: 16 May 2024 — Issue date: 01 Jul 2024
THPR44
Study of stripping magnets for LACE at the SNS
3607
We study possibility of laser assisted charge exchange injection at the SNS. The realistic injection of LACE injection and accumulation into the Ring of SNS is considered. The design of stripping magnets at the injection area is one of the most challenging problems toward operational scheme of LACE at the SNS. Basic requirements and needed parameters of stripping magnets are studied. Based on this study the possibility of real stripping magnet design is considered.
Paper: THPR44
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPR44
About: Received: 15 May 2024 — Revised: 17 May 2024 — Accepted: 18 May 2024 — Issue date: 01 Jul 2024
THPR71
Container stripping: enhanced classification of materials within cargo containers
3681
For cargo and vehicle inspection, where high energy linear accelerators are used, materials within radio-graphic images can be classified using their atomic number (Z). The identification and classification of materials and objects within cargo containers can be difficult, due to the nature of energy spectra and their impact on the discrimination of materials. This can also be impacted by system-level factors, such as the stability of the linear accelerator and the alignment of the system. By removing the container from images of cargo, materials inside can be classified with higher confidence. When a low-Z, low density organic material is obscured by a 5 mm thick steel container, its effective-Z value changes and it can colorise as green rather than orange. This could lead to mis-classification of materials by an operator, potentially leading to the mis-identification of threatening materials. Further to the container removal, extra layers can be ‘stripped’ away to better reveal certain areas of interest. In future, this could be tied in with operator-assisting algorithms, as part of an enhanced image quality analysis package.
Paper: THPR71
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPR71
About: Received: 08 May 2024 — Revised: 22 May 2024 — Accepted: 22 May 2024 — Issue date: 01 Jul 2024
THPR73
Status of ABC production line at Varex Imaging Corporation
3687
During past 7 years at Varex Imaging Corporation, we have created a pilot production line for Accelerator Beam Centerlines (ABC), replacing supply of Beam Centerlines (BCL) by Varian after the Component Division separated from Varian in 2017, becoming an independent public company. Our ABC production growth rate seems to double every year, and in last quarter of 2023 Fiscal Year, we delivered 35 ABCs, satisfying Industrial group full demand in such ABCs. In this 2024 Fiscal Year started on 1 October 2023, our goal is to deliver 12 units per month, but the stretch goal is to produce anywhere between 160 and 200 ABCs, which will include ABCs for 3, 6, and 9 MeV Linacs mostly for security screening, for Non-Destructive Testing (NDT), also a few units for our customers in radiation therapy business. We drive to complete the transition away from Varian to 100% in-house ABC production in 2025,
Paper: THPR73
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPR73
About: Received: 07 May 2024 — Revised: 20 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
THPR82
Information display board system to enhance safety management at the National Synchrotron Radiation Research Center
3701
The National Synchrotron Radiation Research Center houses two accelerators, namely the Taiwan Light Source and the Taiwan Photon Source. It also includes approxi-mately 40 end stations. The center has an information display board system that integrates information from the Instrumentation and Control Group, Experimental Facilities Division, Scien-tific Research Division, Radiation and Operation Safety Division, and User Administration and Promotion Office in the form of interactive display pages. It provides cru-cial information, such as source status, beamline details, and user sign-in data, as well as useful resources, such as end-station training courses and experimental safety approval forms. The system offers diverse use cases tailored to the spe-cific needs of different users. This paper describes how we use the information display board system to improve safety management at the center.
Paper: THPR82
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPR82
About: Received: 05 May 2024 — Revised: 17 May 2024 — Accepted: 17 May 2024 — Issue date: 01 Jul 2024
THPR83
Electrical fire safety assessment of the synchrotron accelerator experimental station in NSRRC
3704
The synchrotron facility and experimental station in the National Synchrotron Radiation Research Center (NSRRC) uses many electrical appliances, the improper use of which can cause fires, resulting in property damage and personal injury. Therefore, the usage of these electri-cal appliances must be assessed. This study conducted a comprehensive inspection and evaluation of the electrical appliances used in NSRRC, including extension cords and electrical connections; this was done to not only reduce the risk of fire but also emphasize the importance of electrical safety habits. We connected an extension cord reel in the NSRRC to a pump or a dehumidifier and used a thermal imaging cam-era to measure the temperature of the cord and these two appliances. We tested the extension cord reel when it was coiled up in the reel and straightened to determine which electrical appliances or extension cord states were prone to high temperatures and fires. The results showed that the extension cord was 18–20°C hotter when it was coiled than when it was straight. Therefore, we recommend that at least two-thirds of the length of the extension cord should be extended out of the reel when it is used.
Paper: THPR83
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPR83
About: Received: 05 May 2024 — Revised: 19 May 2024 — Accepted: 19 May 2024 — Issue date: 01 Jul 2024
THPR84
Development of a quality test platform for solid-state power amplifiers in NSRRC
3707
To rule out Solid-State Power Amplifier (SSPA) modules with defects due to handmade and reduce time cost of maintenance for deployed modules, it is essential to establish a comprehensive testing platform that includes a complete quality control system. In this study, we developed a platform with function of manipulating driving power and shutting down when failures are detected.
Paper: THPR84
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPR84
About: Received: 14 May 2024 — Revised: 16 May 2024 — Accepted: 17 May 2024 — Issue date: 01 Jul 2024
THPS01
STAR High-Energy Linac status: complete installation acceptance tests
3718
The installation of the STAR High-Energy Linac, the energy upgrade of the Southern European Thomson Back-Scattering Source for Applied Research (STAR) project at the University of Calabria, was conducted by INFN by the end of 2023. This paper presents the testing procedures aimed at confirming the consistency, completeness, and quality of the STAR accelerator upgrade installation (electron beam energy boost from 65 MeV up to 150 MeV). We illustrate the installation and testing of the electrical, hydraulic and related automation and auxiliary systems. We will discuss the high-power commissioning of the two C-band RF power stations and testing of the low-level C-band RF system and control system configuration based on EPICS. Finally, we will describe the layout and testing of the vacuum system, the characterization and commissioning of the magnets with related power supplies and the assessment of the installed diagnostics devices. The linac commissioning as well as electron beam measurements are planned for Summer 2024, due to pending radioprotection authorizations.
Paper: THPS01
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPS01
About: Received: 15 May 2024 — Revised: 20 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
THPS08
Modernizing of magnet power supplies at KARA and a transition to EPICS-based control system
3739
This paper presents a study on the upgrade and modernization of the magnet power supplies of the KARA (Karlsruhe Research Accelerator) storage ring. The existing power supplies, which have been in operation for more than two decades, were facing obsolescence and operational limitations. To ensure the continued availability and reliability of the facility for the next decade and beyond, a comprehensive refurbishment was required. The project involved the replacement and upgrade of the power supplies for the dipole and sextupole magnets at KARA, as well as for the dipole and quadrupole magnets in the booster. A key aspect of this modernization effort beside an improvement in efficiency and stability is the migration from a custom control system to EPICS running embedded on the power supplies. This paper provides an in-depth analysis of the motivations, goals, and technical aspects of the power supply modernization project as well as first measurements with the new power supplies and the project status.
Paper: THPS08
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPS08
About: Received: 15 May 2024 — Revised: 20 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
THPS09
Development of linear power operational amplifier for TPS correction magnet power supply
3742
This paper investigates the design and implementation of a TPS correction magnet power supply using a combination of a linear power operational amplifier (PA05) and a pre-regulator voltage controller. The PA05 linear power operational amplifier features bipolar output, high internal power dissipation, and wide bandwidth. Utilizing a DCCT sensor as a current feedback element integrated with the pre-regulator voltage controller, a closed-loop current modulation circuit is formed, providing the variable voltage required by the linear power operational amplifier. We have successfully developed a prototype of a linear power operational amplifier power supply with a pre-regulator voltage controller for TPS correction magnets through these measures. Design validation is achieved through control loops, resulting in fast and stable output current performance. The output current ripple is maintained below 100 μA, and the rise time during the step response is 75 μs. During the frequency response test using a 0.1 V interference signal, the gain margin remained within -3 dB at an 11.2 kHz bandwidth, and the phase margin was within -45 ° over a range of 5.1 kHz. The long-term stability of the output current is maintained at ten ppm. Finally, a hardware prototype circuit is assembled in the power laboratory with input voltage ranging from ±24 V, an output current of ±20 A, and a maximum rated power of 240 W.
Paper: THPS09
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPS09
About: Received: 05 May 2024 — Revised: 17 May 2024 — Accepted: 17 May 2024 — Issue date: 01 Jul 2024
THPS10
Development of high-current correction magnet power supply for TPS facilities
3745
In this paper, the focus is on the development of a bipolar high-current correction magnet power supply for the future TPS-II permanent magnet corrector coil. The maximum output current of the prototype is speci-fied as 20 A, operating at a voltage of 48 V. This con-figuration enhances the amplitude of the trim magnetic core correction magnetic field, thereby providing greater flexibility in manufacturing the permanent magnet corrector coil. The Danisense DP50-IP-B DCCT is the current feedback component to design a power supply with high current and stability. MOSFETs are configured in a full bridge setup serving as power switches. The driving frequency is set at 40 kHz. Analogue modulation control circuitry and pro-tection circuits ensure precise current control loop modulation. Finally, a hardware prototype circuit is constructed in the power supply laboratory with an input voltage of 48 V, an output current of 20 A, a maximum power of 960 W, and the current ripple com-ponent maintained within 400 μA. This validates the control loop design of the prototype, demonstrating the capability to achieve rapid and stable output cur-rent performance. The small-signal bandwidth tested using a 1V input reference signal shows a -3 dB band-width of 8.51 kHz. Long-term current stability is with-in ±10 ppm, and the interface is compatible with exist-ing TPS correction magnet power supply interfaces, allowing for direct operation within the current sys-tem.
Paper: THPS10
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPS10
About: Received: 05 May 2024 — Revised: 18 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
THPS11
Cold plate upgrade at the SNS
3748
The Spallation Neutron Source (SNS) employed over 200 cold plates in its Injection Kicker and quadrupole power supplies for semiconductor cooling. Each cold plate consisted of an aluminum base with interconnected copper tubes that were brazed together. Unfortunately, the durability of these plates was compromised over time due to corrosion of the copper tubes by de-ionized water. This corrosion led to the formation of small pinhole leaks, which became increasingly problematic in recent years, causing more frequent leaks and subsequent operational downtime for the SNS system. To tackle this issue, a novel solution was pursued involving the incorporation of stainless-steel tubes in the redesign. Two types of cold plates underwent rigorous simulations and extensive testing. One of the redesigned cold plates demonstrated competitive performance and was identified as a feasible replacement option. Consequently, a comprehensive initiative was executed to replace all cold plates.
Paper: THPS11
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPS11
About: Received: 30 Apr 2024 — Revised: 16 May 2024 — Accepted: 16 May 2024 — Issue date: 01 Jul 2024
THPS12
LCLS II DC magnet power supplies – an overview
3751
The Linac Coherent Light Source II (LCLS-II) at the SLAC National Accelerator Laboratory represents a groundbreaking advancement in the realm of Free Electron X-Ray Laser (XFEL) science. This 1.3 GHz continuous-wave superconducting RF LINAC is designed to generate 4 GeV electron bunches up to one MHz, propelling the capabilities of XFEL sources. Achieving a significant milestone, the LCLS-II successfully reached its 2K operating temperature with the first electrons in October 2022, culminating in the generation of the first x-rays in September 2023. This paper offers an overview of the diverse array of DC magnet power supplies (PSs) employed in LCLS-II, which can be categorized into two sections: warm and superconducting. The warm section comprises of two crucial types of PSs-intermediate and trim. Notably, these PSs are subjected to tight stability requirements as low as 20 ppm. The warm section has close to 600 PSs. In the superconducting section, an extra level of complexity is added by including a quench protection circuit to protect the magnets in case of a sudden loss of superconductivity. PSs in this section also have a stability requirement of 0.02 %. The superconducting section has 105 PSs. This paper also discusses the system design and performance of these PSs.
Paper: THPS12
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPS12
About: Received: 30 Apr 2024 — Revised: 16 May 2024 — Accepted: 18 May 2024 — Issue date: 01 Jul 2024
THPS13
Implementation and experience with the pilot CMDS control system at TS2, in view of operating the ESS LINAC cryogenics
3754
This paper introduces the strategy for operating the cryogenic system of the ESS superconducting LINAC, emphasizing the integration of individual cryomodules and valve boxes within an unified system. The study focuses on the practical implementation of this strategy at Test Stand 2 (TS2) as a pilot project, validating the proposed control system in a real-world setting. The paper evaluates the primary goals which include performing functional tests, successful implementation, identifying control system shortcomings, and collecting valuable operator feedback for continuous improvement.
Paper: THPS13
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPS13
About: Received: 15 May 2024 — Revised: 18 May 2024 — Accepted: 18 May 2024 — Issue date: 01 Jul 2024
THPS17
New insertion devices for BRIGHT beamlines at the Australian Synchrotron
3765
In 2016 the Australian Synchrotron embarked on the BRIGHT program to build four new insertion device beamlines: Biological Small Angle X-ray Scattering (BioSAX), High Performance Macromolecular Crystallography, Advanced Diffraction and Scattering and Nanoprobe beamlines. To maximize the flux for these very demanding beamlines, cryogenic and short period devices have been selected. In particular a 1.6 m long 16 mm period superconducting undulator, a 3 m long 18 mm period cryogenic undulator (CPMU), 3 m long 17 mm in-vacuum undulator and a 2 m long 48 mm period superconducting wiggler. This report will discuss some of the design considerations and overall parameters of the new insertion devices.
Paper: THPS17
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPS17
About: Received: 16 May 2024 — Revised: 21 May 2024 — Accepted: 22 May 2024 — Issue date: 01 Jul 2024
THPS21
Strain measurements of the Apple-X SABINA undulator with fiber Bragg grating
3777
The SABINA project will add a user facility to SPARC_LAB at INFN in Frascati (Rome). For the THz line, an electron beam is transported to the APPLE-X undulators to produce photon pulses in the ps range, with energy of tens of µJ, with linear or elliptical polarization. Each undulator has four magnetic arrays that can be moved radially simultaneously to set the operating gap. Two arrays can also move longitudinally for phase displacement. A structural analysis of this unique mechanical structure has been performed by the production company (KYMA S.p.a) to ensure good field quality and beam trajectory. To support those, a set of tests has been performed with FBG acting as strain sensors in Frascati. An FBG is a phase grating inscribed in the core of a single-mode fiber, whose Bragg-diffracted light propagates back along the fiber. Any deformation of the grating affects its pitch, which changes the diffracted Bragg wavelength thus giving information about the occurred deformation. Application of the technique at the state-of-the-art level allows to perform strain measurements with 1 µStrain resolution. Such analysis and results will be presented in this contribution.
Paper: THPS21
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPS21
About: Received: 15 May 2024 — Revised: 20 May 2024 — Accepted: 20 May 2024 — Issue date: 01 Jul 2024
THPS23
Design and fabrication of the automation system in TLS BL07A end station
3785
The end station for TLS beamline 07A (BL07A) primarily serves industrial applications, catering to various sample inspection requirements within the industry in multiple modes. In the past, manual switching of modes for different experiments was time-consuming, requiring the re-installment a lot components and taking long time to readjust the gas proportion for different samples. To enhance the efficiency of the BL07A experimental station, an automated design has been implemented, utilizing multiple self-made motorized platforms. Another crucial aspect for improved experimental efficiency is the use of a combination of vacuum pumps, flow meters, and electromagnetic valves for gas replacement system, significantly reducing the time needed for this process. The automated system is currently operational, reducing the operation time for experimental equipment switching from several hours to two minutes. The execution time for the gas replacement process has also been drastically reduced from 100 minutes to 5 minutes.
Paper: THPS23
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPS23
About: Received: 10 May 2024 — Revised: 16 May 2024 — Accepted: 16 May 2024 — Issue date: 01 Jul 2024
THPS24
Assembly process and inspection results for W100
3788
The 100 mm periodic permanent magnet Wiggler (W100) was installed in the 31st straight section of the TPS storage ring in September 2020, during a prolonged shutdown of the TPS. It provides photon energy ranging from 5 to 50 keV for user experimental applications. The mechanical structure of this facility involves assembling and connecting it to the upper and lower magnetic arrays, each approximately 500 mm in length. Precise control of the gap between the magnetic arrays and accurate adjustments are required. This report primarily describes the assembly process of various components of W100 and the inspection items along with the results.
Paper: THPS24
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPS24
About: Received: 15 May 2024 — Revised: 22 May 2024 — Accepted: 22 May 2024 — Issue date: 01 Jul 2024
THPS26
Cryogenic permanent magnet undulator at high beam currents
3794
Cryogenic permanent-magnet undulators (CPMUs) have become a point of interest in the development of short-period undulators. However, electron beam-induced heating presents a significant challenge to CPMU devel-opment. The CU15, using a conduction-cooled cooling mechanism, demonstrates exceptional spectral and opera-tional performance, even when operating at small gaps with a beam current of 500 mA. This CPMU has served as a reliable light source for a powder-diffraction beamline for over three years.
Paper: THPS26
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPS26
About: Received: 15 May 2024 — Revised: 16 May 2024 — Accepted: 16 May 2024 — Issue date: 01 Jul 2024
THPS27
Development of a cryogen free MgB2 high temperature superconducting undulator
3797
RadiaBeam is designing and manufacturing a 15-mm period, 1.15 T field superconducting undulator. Realizing these parameters require a small gap, on the order of 5 mm. This small gap imparts a thermal management challenge due to heating from resistive walls, wakefields, upstream dipoles, and particle losses which is challenging to overcome with NbTi or NbSn3 wires without the use of liquid helium. Further, to reduce operating costs and reliance on liquid helium infrastructure, this undulator is designed to run off cryocoolers. In order to provide sufficient thermal overhead for cryocooling capacities, we will utilize Magnesium Diboride (MgB2), a metallic superconductor with a transition temperature at around 39 K. Thermo-mechanical engineering design studies and production plans of our prototype will be presented.
Paper: THPS27
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPS27
About: Received: 14 May 2024 — Revised: 21 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
THPS30
Design and characterization of adjustable-length pulse generator for beam kicker system
3803
The contemporary advancement in particle accelerator technology necessitates precise control over beam manipulation for various experimental and industrial applications. One pivotal aspect of this control resides in the generation and modulation of high-voltage pulse to manipulate the trajectory and behavior of particle beams within the accelerator systems. This extensive study delves into the design, development, and characterization of an adjustable-length pulse generator specifically tailored for a beam extraction kicker system, which is employed to navigate the beam out of the photon storage ring. The primary aim of this research is to engineer a versatile and reliable pulse-length modulation mechanism for a high-voltage pulse generation, which is capable of producing adjustable pulses with ultra-fine precision to meet the demanding requirements of beam manipulation within the accelerator setup. The system's design encompasses a meticulous integration of electronic components, waveform shaping modules, and control mechanisms to achieve the desired output.
Paper: THPS30
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPS30
About: Received: 15 May 2024 — Revised: 22 May 2024 — Accepted: 22 May 2024 — Issue date: 01 Jul 2024
THPS31
A 50 kV pulse generator for fast kickers
3806
Brookhaven National Laboratory has recently been selected as the site for the Electron-Ion Collider (EIC). The EIC will consist of two intersecting accelerators, one producing an intense beam of electrons, the other a high-energy beam of protons or heavier atomic nuclei, which are steered into head-on collisions. One of the sections of the EIC beamline will require a hadron injection fast kicker system. RadiaBeam is developing GaN-based pulser with ±50 kV voltage amplitude, <4 ns rise and fall times, 40 ns pulse width. In this paper, we discuss the development progress.
Paper: THPS31
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPS31
About: Received: 16 May 2024 — Revised: 21 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
THPS40
Thermal-fluid analysis and operation of a low power water-cooled tilted beam dump at Facility for Rare Isotope Beams
3823
The Facility for Rare Isotope Beams is a high power heavy ion accelerator completed in April 2022. The FRIB accelerator was commissioned with acceleration of heavy ions to energies above 200 MeV/nucleon (MeV/u) that collide onto a rotating single-disk graphite target. The remaining beam is absorbed by a water-cooled static beam dump that is oriented at a 6 degrees angle with respect to the beam. The beam dump consists of the beam stopper made of machined Aluminum 2219 block, and 3D-printed inlet and outlet parts made of Aluminum 6061 that delivers the cooling water from utilities to the beam stopper and its return. This low power beam dump is designed for up to 10 kW beam power. This paper presents a discussion on the thermal-fluid behavior of the beam dump for various beam species and beam power.
Paper: THPS40
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPS40
About: Received: 13 May 2024 — Revised: 19 May 2024 — Accepted: 19 May 2024 — Issue date: 01 Jul 2024
THPS41
Thermal analysis of rotating single slice graphite target system for FRIB
3827
The Facility for Rare Isotope Beams (FRIB) is a high power heavy ion accelerator facility at Michigan State University completed in 2022. Its driver linac is designed to accelerate all stable ions to energies above 200 MeV/u with beam power of up to 400 kW. Currently FRIB is operating at 10 kW delivering various primary beams. The target absorbs roughly 25% of the primary beam power and the rest is dissipated in the beam dump. This paper presents a brief overview of the current production target system and details the thermal analysis ANSYS simulations utilized for temperature and stress prediction. The existing single-slice rotating graphite target can accommodate up to 40 kW for lighter beams, with a planned transition to a multi-slice concept.
Paper: THPS41
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPS41
About: Received: 09 May 2024 — Revised: 21 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
THPS42
Pressure spike in the LBNF absorber core’s gun drilled cooling channel from an accident beam pulse
3830
The LBNF Absorber consists of thirteen 6061-T6 aluminum core blocks. The core blocks are water cooled with de-ionized (DI) water which becomes radioactive during beam operations. The cooling water flows through gun-drilled channels in the core blocks. The cooling water is supplied by the LBNF Absorber Radioactive Water (RAW) cooling system which is designed as per ASME B31.3 Normal Fluid Service [1]. An uninhibited beam accident pulse striking the water channels was identified as a credible accident scenario. In this study, it is assumed that the beam pulse hits the Absorber directly without interacting with any of the other upstream beamline components. The beam parameters used for the LBNF beam are 120 GeV, 2.4 MW with a 1.2 s cycle time. The accident pulse lasts for 10 µs. The maximum energy is deposited in the 3rd aluminum core block. For the sake of simplicity, it is assumed that the accident pulse strikes the 1 in. ID water channel directly. The analysis here simulates the pressure rise in the water during and after the beam pulse and its effects on the aluminum piping components that deliver water to the core blocks. The weld strengths as determined by the Load and Resistance Factor Design (LRDF) and the Allowable Strength Design (ASD) are compared to the forces generated in the weld owing to the pressure spike. A transient structural analysis was used to determine the equivalent membrane, peak, and bending stresses and they were compared to allowable limits.
Paper: THPS42
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPS42
About: Received: 30 Apr 2024 — Revised: 17 May 2024 — Accepted: 18 May 2024 — Issue date: 01 Jul 2024
THPS49
Integration of FCC-ee RF systems targets and challenges
3849
Following the study progress on the FCC-ee radiofrequency systems (i.e. length of the cryomodules), general services infrastructure (i.e. electrical, cooling, ventilation), transport and handling volumes, and alignment requirements, the 3D integration evolved with a new configuration scenario. This paper describes the new proposal to locate the collider RF elements (400 MHz and 800 MHz cryomodules) at point H, and the booster RF elements (800 MHz cryomodules) at point L, without changing the 5.5 m inner diameter tunnel.
Paper: THPS49
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPS49
About: Received: 15 May 2024 — Revised: 21 May 2024 — Accepted: 21 May 2024 — Issue date: 01 Jul 2024
THPS50
Hardware Commissioning of the HL-LHC Inner Triplet String Facility at CERN: Individual System and Short Circuit Tests
3853
The goal of the High Luminosity-Large Hadron Collider (HL-LHC) Inner Triplet (IT) String test, is to validate the assembly and connection procedures and tools required for its construction, to assess the collective behavior of the superconducting magnet chain in conditions as close as possible to those of their operation in the HL-LHC and to provide a training opportunity for the equipment teams for their work in the LHC tunnel. The IT String includes the systems required for operation at nominal conditions, such as the cryogenics, powering and quench protection systems. This contribution describes the individual system and short circuit tests performed at the IT String as part of the hardware commissioning and preparation for the full exploitation of the facility. After describing the IT String infrastructure, the individual system tests performed on the cryogenic and the associated vacuum systems are detailed. Moreover, the individual system and short circuit tests executed on the warm powering systems part of the magnet circuit including power converters, energy extraction systems and the DC connections are described. The powering interlock controller used for the global interlocking of the magnet circuits is also validated during this phase. The tests described involve the same steps as those planned for the LHC collider. Therefore, they validate the systems to be installed and ensure the time-efficient execution of activities for the HL-LHC project.
Paper: THPS50
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPS50
About: Received: 15 May 2024 — Revised: 21 May 2024 — Accepted: 23 May 2024 — Issue date: 01 Jul 2024
THPS58
Permanent magnet resiliency in CEBAF’s radiation environment: LDRD grant status and plans
3875
As the FFA@CEBAF energy upgrade study progresses, it is important to investigate the impact of radiation exposure on the permanent magnet materials to be used in the upgraded fixed field alternating gradient (FFA) arcs. To address this, Jefferson Lab has awarded a Laboratory Directed Research and Development (LDRD) grant to study the resiliency of several permanent magnet materials placed in a radiation environment similar to that in which they are expected to operate. Samples of NdFeB and SmCo are to be placed alongside appropriate dosimetry in a variety of radiation environments in the beam enclosure and experimental halls at CEBAF. The magnet degradation will be measured, and extrapolated to the higher energies expected during operations after the energy upgrade. This document will describe the current status of the LDRD study, as well as describe the upcoming plans. It will also direct the readers to other proceedings which further detail the work thus far.
Paper: THPS58
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPS58
About: Received: 10 May 2024 — Revised: 16 May 2024 — Accepted: 19 May 2024 — Issue date: 01 Jul 2024
THPS60
Bead-pull measurement procedure for AREAL linear accelerator accelerating structure
3882
In this paper, the widely used RF measurement bead-pull technique for the S-band accelerating structure pre-tuning of the AREAL linear accelerator is presented. Bead-pull measurements were conducted before brazing with various group sets of accelerating cells to evaluate the effectiveness of “smart combinations” for AREAL accelerating structures. The “smart combination” technique represents the grouping of cells with corresponding lengths to achieve the same length sets (triplets for 2π/3 mode) as it is possible. Cell lengths were measured in advance based on TM resonance frequencies measurement. This procedure will significantly reduce the tuning routine required after brazing.
Paper: THPS60
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPS60
About: Received: 14 May 2024 — Revised: 22 May 2024 — Accepted: 22 May 2024 — Issue date: 01 Jul 2024
THPS61
Qualification of components for installation in LHC kicker magnets
3886
LHC injection kickers (MKI) are pulsed at high voltage to achieve magnetic field pulses with fast rise time. The MKIs contain a beam screen to help shield their ferrite yoke from beam induced heating. However, additional means of mitigating beam induced heating, for the high luminosity LHC (HL-LHC) era, are required. To achieve this, the MKIs are sequentially being upgraded to low impedance versions (MKI Cool) with several critical components including (a) a 3-m long alumina tube, installed in the magnet aperture, used to hold screen conductors that help shield the magnet yokes from beam induced heating; and (b) an RF damper which moves beam induced power from the ferrite yoke to a ferrite cylinder which is part of the damper. This paper discusses the measurements carried out to qualify these components for installation in an MKI Cool. In addition, for the alumina tube, the interpretation of the measurement data is discussed together with the optimisation of the angular orientation of the tube in the magnet aperture.
Paper: THPS61
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPS61
About: Received: 14 May 2024 — Revised: 20 May 2024 — Accepted: 20 May 2024 — Issue date: 01 Jul 2024
THPS71
Multi-physics and multi-objective design optimization of quadrupole resonators under geometric uncertainties
3912
Exploring the fundamental properties of materials such as niobium, NbTiN, multilayers or Nb3Sn, in high-precision surface resistance measurements is highly relevant to superconducting radio-frequency (RF) technology. Typically, for a precise determination of the RF properties of superconducting samples, the calorimetric measurement is carried out with a quadrupole resonator (QPR). Still, one of the main challenges in the QPR design and operations is to mitigate the impact of microphonics and Lorentz force (LF) detuning, on the one hand, and the RF losses on the adapter flange with the fabrication tolerances, on the other hand, into QPR functioning. For this reason, we address the electro-stress-heat coupled problem under geometric uncertainties to study a significant measurement bias of the surface resistance, observed mainly for the third operating mode of the given QPR. We then use a multi-objective and multi-physics shape optimization method to compensate for its influence and find the optimal QPR design in the Pareto sense. Finally, the optimization results and their implications for QPR operating conditions are discussed to demonstrate the proposed approach.
Paper: THPS71
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-THPS71
About: Received: 15 May 2024 — Revised: 05 Jun 2024 — Accepted: 05 Jun 2024 — Issue date: 01 Jul 2024
FRXD2
Commissioning of carbon ion treatment accelerator with a superconducting rotating gantry
3921
The world's smallest carbon ion treatment facility has been commissioned at Yamagata University. The treatment system consists of an ECR ion source, a linac cascade of 0.6 MeV/u RFQ and 4 MeV/u IH-DTL, a 430 MeV/u slow extraction synchrotron, and irradiation systems of a fixed horizontal beamline and a compact rotating gantry using superconducting combined function magnets. The size of the building is 45 x 45 m, realized by placing the irradiation rooms not on the same level as the synchrotron, but above it, connected by a vertical beam transport. The most advanced accelerator technology of this machine is to control the beam range up to 300 mm in 0.5 mm steps without any physical block range shifter. To achieve this range step, 600 beam energies were provided in the synchrotron and in the beam transport and tuned to control the beam size in the treatment room. Initial commissioning and daily/monthly quality assurance were carried out by interpolation of beam energy and gantry angle. After tuning the beam size and correcting the beam axis in the treatment rooms, precise dose measurement was performed for clinical irradiation. After the clinical commissioning, the facility started treatment irradiation in February 2021 with a fixed beam port and in March 2022 with a gantry beam port. After March 2023, the gantry angle was operated with a 15-degree step. By November 2023, 1330 patients had been treated.
Paper: FRXD2
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-FRXD2
About: Received: 15 May 2024 — Revised: 20 May 2024 — Accepted: 20 May 2024 — Issue date: 01 Jul 2024
FRXN3
Crystal collimation of heavy-ion beams
3927
An important upgrade programme is planned for the collimation system of Large Hadron Collider (LHC) for lead–ion beams that will already reach their high-luminosity target intensity upgrade in the LHC Run 3 (2022-2025). While certain effects like e-cloud, beam-beam, impedance, inject and dump protection are relaxed with ion beams, halo collimation becomes a challenge, as the conventional multi-stage collimation system is about two orders of magnitude less efficient than for proton beams. Ion fragments scattered out of the collimators in the betatron cleaning insertion risk to quench cold dipole magnets downstream and may represent performance limitations. Planar channeling in bent crystals has been proven effective for high energy heavy ions and is now considered as baseline solution for collimation at High-Luminosity LHC (HL-LHC). In this paper, simulation and measurement results, demonstrating the observation of channeling of heavy-ion beams and improvement of collimation cleaning in the multi-TeV energy regime, and the efficiency of the collimation scheme foreseen for HL-LHC are presented.
Paper: FRXN3
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-FRXN3
About: Received: 13 May 2024 — Revised: 22 May 2024 — Accepted: 22 May 2024 — Issue date: 01 Jul 2024
FRYD2
Recent development and future direction of ring-type synchrotron light sources in Japan
3939
The 4th generation synchrotron light sources and energy recovery linacs progress greatly in Japan. The first 4th generation synchrotron light source in Asia, NanoTerasu, has been constructed through a public-private regional partnership, whereas soon SPring-8 is to be upgraded. The energy recovery linac, which features not only high brightness but also sustainability as the cERL, and its related technology such as DC gun injectors have been developed, also. The talk will present an overview and future direction of synchrotron radiation light sources in Japan, with a particular focus on recent advances in NanoTerasu.
Paper: FRYD2
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-FRYD2
About: Received: 12 May 2024 — Revised: 17 May 2024 — Accepted: 17 May 2024 — Issue date: 01 Jul 2024
FRYD3
Particle colliders: options for the US and internationally
3944
In the US high energy planning process more than 30 colliders were considered. This talk gives an overview of these colliders and emphasized the strength of the various approaches.
Paper: FRYD3
DOI: reference for this paper: 10.18429/JACoW-IPAC2024-FRYD3
About: Received: 14 May 2024 — Revised: 16 May 2024 — Accepted: 16 May 2024 — Issue date: 01 Jul 2024