experiment
MOZG1
Electron beam test facilities for novel applications
32
Delivering and tailoring high brightness electron beams for a wide range of novel applications is a challenging task in single pass accelerator test facilities. This paper will review beam dynamics challenges at single pass accelerator test facilities in Europe to generate, transport and tailor low- to medium-energy high brightness electron beams for a range of novel applications.
Paper: MOZG1
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOZG1
About: Received: 03 May 2023 — Revised: 09 May 2023 — Accepted: 12 May 2023 — Issue date: 26 Sep 2023
MOOG3
Additive manufacturing of copper RF structures for particle accelerator applications
53
Particle accelerators, relevant to LANL’s mission spaces will rely on the use of copper based rf structure for charged particle acceleration. Additively manufactured (AM) copper structures offer the usual well-known advantages in terms of relaxation of physical design (shape) constraints, and thus hold the promise of making complex shaped rf structures. To rapidly demonstrate the potential to additively manufacture accelerator structures with existing technology, a bound metal deposition (BMD) metal 3D printer will be used to build a scaled design and the results of this effort will be presented.
Paper: MOOG3
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOOG3
About: Received: 03 May 2023 — Revised: 15 Jun 2023 — Accepted: 15 Jun 2023 — Issue date: 26 Sep 2023
MOPA008
Status of CARIE facility design and construction
66
Building new experimental facilities to house experiments is an expensive and time-consuming activity. Although usually less expensive, repurposing old experimental facilities to accommodate new ones has its own set of challenges with regard to obsolete equipment, adequacy of electrical power, radioactive shielding and cooling capacity. At Los Alamos National Laboratory (LANL), one such facility was previously used to provide a platform for Free Electron Laser (FEL) experiments that were completed 20 years ago. This paper explores the techniques and process to repurpose an existing experimental facility to accommodate the CARIE compact accelerator and the choices made to select and size equipment for success. Radio Frequency (RF) energy waveguide layout with vacuum calculation methods will be included as well as electrical power and radiation shielding requirements.
Paper: MOPA008
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPA008
About: Received: 06 May 2023 — Revised: 07 May 2023 — Accepted: 11 May 2023 — Issue date: 26 Sep 2023
MOPA067
Experimental measurements on impedance and beam instability in BEPCII
181
The BEPCII has already realized the collision luminosity target of $1.0\times10^{33}cm^{-2}s^{-1}$ in April 2016. However, in the past six years of practical operation, the collision luminosity usually remains between $6.0\times10^{32}cm^{-2}s^{-1}$ and $8.5\times10^{32}cm^{-2}s^{-1}$. In the operation with high beam current, the BEPCⅡ displayed serious beam instabilities, which greatly limits the increase of collision luminosity. A series of machine studies and analyses were conducted. According to the bunch lengthening experiments, the longitudinal effective impedance is $0.162\Omega$ for electron storage ring and $0.195\Omega$ for positron storage ring. According to the tune shift measurements, the transverse effective impedances are $0.02840\Omega/m$ horizontally and $0.05253\Omega/m$ vertically for electron storage ring, and $0.04223\Omega/m$ horizontally and $0.06714\Omega/m$ vertically for positron storage ring. The oscillation mode distribution was obtained from experiments, showing that the transverse beam coupling instability has become an important factor for limiting the increase of beam current and luminosity. Finally, some possible origins of transverse narrow-band impedance, such as the resistive wall and vertical masks, were checked. The calculated results match with the experiment results quite well. The results in this study give important references for establishing feedback systems and increasing the collision luminosity in the future research.
Paper: MOPA067
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPA067
About: Received: 01 May 2023 — Revised: 06 Jun 2023 — Accepted: 16 Jun 2023 — Issue date: 26 Sep 2023
MOPA070
Spin coherence and betatron chromaticity of deuteron beam in NICA storage ring
190
The possibility of spin control for dEDM experiment can be done by setting Wien Filters in straight section, which ensure that the particles spin retains mean direction in accordance with «Quasi-Frozen Spin» mode. However, the spin of different particles, due to their different motion in 3D space, in any case rotates with slightly different frequencies around the invariant axis, which one violates spin coherence. To ensure spin coherence, nonlinear elements, sextupoles, with a special placement on arcs must be used. Since sextupoles simultaneously affects the betatron chromaticity, we consider this complicated case.
Paper: MOPA070
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPA070
About: Received: 03 Apr 2023 — Revised: 09 May 2023 — Accepted: 12 May 2023 — Issue date: 26 Sep 2023
MOPA072
ByPass optics design in NICA storage ring for experiment with polarized beams for EDM search
196
NICA is mainly designed for experiments with heavy ions and polarized proton and deuteron beams at an energy of the former about 13 GeV. For these purposes, appropriate SPD and MPD detectors, as well as other necessary implements, are installed in the straight sections. EDM experiment supposes use deuterons at an energy of about 240 MeV. To ensure the «Quasi-Frozen Spin» mode, E+B elements (namely, Wien Filters) are required as well. Such elements can be placed in straight sections to compensate the arc spin rotations. For EDM measurement experiments, it is necessary to operate NICA in the storage ring, and not the collider mode. To do this, it is proposed to install ByPass channels. Thus, it is possible to create a completely new regular structure in a straight section. Creating ByPass channels will make possible to engage NICA in various experiments at once.
Paper: MOPA072
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPA072
About: Received: 03 Apr 2023 — Revised: 09 May 2023 — Accepted: 16 Jun 2023 — Issue date: 26 Sep 2023
MOPA077
Numerical analysis on the air conditioning system of the experimental hall at TPS
209
Taiwan Photon Source (TPS) had delivered the first synchrotron light on the last day of 2014. Installation of 16 beamlines of the first and second phases of TPS beamline project was completed. The third phase project also had been launched in 2021. To confront the situation that the experimental hall is more compact, we per-formed Computational Fluid Dynamic (CFD) simulation to analyse the effects of the air conditioning system and various heat sources to the temperature and flow fields in the experimental hall.
Paper: MOPA077
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPA077
About: Received: 11 May 2023 — Revised: 12 May 2023 — Accepted: 15 Jun 2023 — Issue date: 26 Sep 2023
MOPA080
Particle accelerators to meet gravitational waves
218
The observation of the Higgs boson by the LHC (2012), and the direct observation of gravitational waves (GW) from a collapsing binary systems by LIGO (2016) marked the successful end of long-standing efforts, and hopefully the dawn of a new era where both fields, Particle Accelerators (PA) and GW Physics, may benefit from knowledge/technologies developed by the other party. CERN recently hosted a meeting (SRGW2021) where such synergies were discussed, including the possibility of operating storage-rings/colliders as GW sources/detectors. Earth-bound interferometric GW detectors may explore only a tiny subset of the GW spectrum. Spaceborne detectors (LISA) and pulsar-timing observatories will open a window in the LF to ELF range, and different HF to SHF detectors have been proposed (SISSA2019). Observations at these frequencies would bring rich astrophysical/cosmological information. On the other hand, PA advances in superconducting magnets, and extremely high-Q RF cavities, and the (still controversial) possibility that superconductors may act as GW reflectors, suggest to reconsider the feasibility of a GW “Hertz experiment” based on Gertsenshteyn effect; while progress in (big) data analysis, control systems and optical materials from GW experiments may be useful for next gen PA. We review these ideas from a dual perspective, and highlight possible directions for common work.
Paper: MOPA080
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPA080
About: Received: 05 May 2023 — Revised: 30 Jun 2023 — Accepted: 30 Jun 2023 — Issue date: 26 Sep 2023
MOPA084
Investigating the feasibility of delivering higher intensity proton beams to ECN3 at the CERN SPS North Area
229
Initiated through the Physics Beyond Colliders (PBC) Study Group there is a strong interest from the scientific community to exploit the full intensity potential of the Super Proton Synchrotron (SPS) at CERN for Fixed Target physics experiments before the end of this decade. With the ECN3 cavern in the North Area (NA) identified as a suitable candidate location for a future high-intensity experimental facility compatible with a large variety of experiments, the new PBC ECN3 Beam Delivery Task Force was mandated to assess the feasibility of delivering a slow extracted beam of up to 4x10^19 protons per year at 400 GeV. This contribution summarises the conclusions of the multifaceted beam physics and engineering studies that have been carried out recently to understand the present intensity limitations and to find technical solutions to meet the request for higher intensity in the NA transfer lines towards ECN3. The necessary modifications to the beam lines, the primary target area, beam instrumentation and intercepting devices, as well as the relevant infrastructure and services are outlined, along with a timeline compatible with the NA consolidation project that is already underway.
Paper: MOPA084
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPA084
About: Received: 11 Apr 2023 — Revised: 28 Jun 2023 — Accepted: 28 Jun 2023 — Issue date: 26 Sep 2023
MOPA088
Conceptual design of the magnetised iron block system for the SHADOWS experiment
245
The SHADOWS experiment is a proposed beam dump experiment in the CERN North Area, aiming to search for feebly interacting particles (FIPs) created in 400 GeV/c proton interactions. Due to its intended off-axis location alongside the K12 beam line, the SHADOWS detector can be placed potentially very close to the dump, enabling it to look for FIPs in non-covered parts of the parameter space. To guarantee a good quality of a potential signal, it is crucial to reduce any backgrounds of Standard Model particles as much as possible. The dominant background downstream the beam dump is caused by muons. This gives rise to introducing a dedicated muon sweeping system consisting of magnetised iron blocks (MIBs) to actively mitigate this background component. We present the conceptional design studies in the framework of the Conventional Beams Working Group of the Physics Beyond Colliders Initiative at CERN.
Paper: MOPA088
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPA088
About: Received: 01 Apr 2023 — Revised: 08 Jun 2023 — Accepted: 08 Jun 2023 — Issue date: 26 Sep 2023
MOPA115
Beam delivery of high-energy ion beams for irradiation experiments at the CERN Proton Synchrotron
315
Heavy-ion single event effect (SEE) test facilities are critical in the development of microelectronic components that will be exposed to the ionizing particles present in the hostile environment of space. CHARM High-energy Ions for Micro Electronics Reliability Assurance (CHIMERA) and HEARTS have developed a high-energy ion beam capable of scanning a wide range of Linear Energy Transfer (LET) at low intensities to study ionization effects on space-bound technology using CERN's Proton Synchrotron (PS). This contribution describes the extraction and transport of low-intensity lead ions at multiple energies to the CHARM facility at the East Area of CERN. Furthermore, it discusses the implementation of a Radio Frequency Knockout (RFKO) technique that streamlines beam extraction and enhances particle flux control and reproducibility across different energies, thereby improving performance and reliability in SEE testing.
Paper: MOPA115
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPA115
About: Received: 21 Apr 2023 — Revised: 15 May 2023 — Accepted: 20 Jun 2023 — Issue date: 26 Sep 2023
MOPA118
Demonstration of three-dimensional spiral injection for the J-PARC muon g-2/EDM experiment
327
In the J-PARC Muon g-2/EDM experiment, to measure muon g-2 and EDM, it is necessary to accumulate 300 MeV/c muon beams with a 66 cm diameter region with a 3 T solenoid-type magnetic field. A new three-dimensional spiral injection scheme has been invented to achieve this target. Since this is the first instance to employ this injection scheme, a scale-down experiment with an electron beam of 297 keV/c and storage beam diameter of 24 cm is established at KEK. A simplified storage beam monitor using scintillating fiber has been designed and fabricated to measure the stored beam. The 100 nanosecond width pulsed beam is injected and observed a few microsecond signals by stored beam monitor. According to this result, the beam storage is confirmed. And the recent result shows that the stored beam deviated from the design orbit and caused betatron oscillations. To measure the beam deviation quantitatively and tune the beam, the storage monitor has been updated. The data from this stored beam monitor are the primary data for considering the conceptual design of the beam monitor for the Muon g-2/EDM experiment. This talk will discuss the measurement of beam storage by three-dimensional spiral injection and beam tuning using a scintillating fiber monitor.
Paper: MOPA118
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPA118
About: Received: 01 Apr 2023 — Revised: 11 May 2023 — Accepted: 20 Jun 2023 — Issue date: 26 Sep 2023
MOPA139
Development of fast BBA for Diamond Light Source
376
Beam-based alignment (BBA) is a standard tool at accelerators for aligning particle beams to the centre of quadrupole magnets. Traditional BBA measurements have been slow, potentially taking many hours for a whole machine. We have developed a tool, based on results previously reported at the ALBA synchrotron, that uses fast excitation of magnets to greatly speed up measurements. We show results of different measurement and analysis techniques, and comparison with the currently used slow method.
Paper: MOPA139
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPA139
About: Received: 12 Apr 2023 — Revised: 04 May 2023 — Accepted: 11 May 2023 — Issue date: 26 Sep 2023
MOPA149
Testing of a fan-out kicker to protect collimators from low-emittance whole-beam aborts in the Advanced Photon Source storage ring
404
In the Advanced Photon Source Upgrade storage ring, the horizontal collimators protect the rest of the machine from whole beam aborts; however, as shown in previous experiments, the collimators themselves must also be protected from the full intensity of the lost store. The suitability of a vertically-deflecting fan-out kicker was evaluated experimentally. Aborted beam strikes the surface of the collimator with the expectation that the absorbed energy density or dose is reduced sufficiently to maintain the integrity of the device. We discuss the results from recent measurements where a fan-out kicker was employed to test this concept. 6 GeV, 200 mA (737-nC) APS stored beam was used to irradiate both aluminum and copper collimator test pieces.
Paper: MOPA149
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPA149
About: Received: 03 May 2023 — Revised: 06 Jun 2023 — Accepted: 06 Jun 2023 — Issue date: 26 Sep 2023
MOPA155
PETRA III operation and studies in 2022
415
The Synchrotron Light Source PETRA III is one of the core facilities at DESY offering each year more than 2000 users unique opportunities for experiments with hard X-rays of a very high brilliance. The light source is operated mainly in two operation modes with 480 and 40 bunches at a beam energy of 6 GeV. The availability and failure statistics is reviewed for the year 2022 in comparison with previous years. Studies at PETRA III are supporting the technical design phase for the planned upgrade PETRA IV. Several diagnostic devices have been tested and the installation of a cavity has been prepared. Furthermore, the operation of PETRA III at 5 GeV has been studied with the goal to reduce the electric power consumption of the accelerator. But a 5 GeV test run for all beam lines at PETRA III showed that this operation mode is impairing the experimental opportunities due to the lower brilliance and photon flux for hard X-rays.
Paper: MOPA155
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPA155
About: Received: 13 Apr 2023 — Revised: 05 May 2023 — Accepted: 11 May 2023 — Issue date: 26 Sep 2023
MOPA157
Motorized girder realignment test in the PETRA III storage ring
418
The system in place for remote alignment of the girders, which carry the storage ring elements of the PETRA III light source in the Max von Laue experimental hall, were never used to perform re-alignments after the initial installation of the storage ring in 2009. Since the planned upgrade, PETRA IV, can benefit from the fine control of the girder position to achieve the design beam performance, a movement test of one of the PETRA III girders was performed in December 2022. The ability to safely and precisely remote control the equipment was demonstrated and the accuracy of the optics model that describes the effect of the girder movement on the orbit could be evaluated. The findings of this experiment are summarized in this paper.
Paper: MOPA157
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPA157
About: Received: 28 Apr 2023 — Revised: 16 Jun 2023 — Accepted: 16 Jun 2023 — Issue date: 26 Sep 2023
MOPA175
Improved signal detection of the steady-state microbunching experiment at the Metrology Light Source
461
The concept of steady-state microbunching (SSMB) as a new scheme for the production of high power synchrotron radiation has been demonstrated at the Metrology Light Source in Berlin-Adlershof (MLS) [1]. At the MLS the same undulator section is used for the generation of the micro-structures onto the electron bunch as well as for the detection of the resulting coherent radiation from the micro-bunches one turn later. Due to the enormous difference in the pulse energy of the micro-bucket generating laser and the coherent undulator pulses showing up 160 ns later, the detection is not straightforward. We show in detail the detection scheme, mostly based on fast optical shutters, and the triggering scheme of the experiment. Ideas for further improvements are discussed. [1] X. Deng et al., Nature, Volume 590, Issue 7847
Paper: MOPA175
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPA175
About: Received: 25 Apr 2023 — Revised: 16 Jun 2023 — Accepted: 16 Jun 2023 — Issue date: 26 Sep 2023
MOPA176
Exploring the necessary conditions for steady-state microbunching at the Metrology Light Source
464
Steady-state microbunching (SSMB) is envisioned to enable the generation of high-power coherent synchrotron radiation at an electron storage ring for wavelengths up to the extreme ultraviolet. The underlying mechanism has been shown to be viable in a proof-of-principle (PoP) experiment at the Metrology Light Source (MLS) in Berlin\*. An enhanced detection scheme allows systematic studies of the conditions needed for the creation of microbunches within the continuing PoP experiment\*\*. It was found that the generation of coherent radiation from microbunches is favored in specific nonlinear longitudinal phase space structures, known as “alpha buckets”, which arise when the momentum compaction function becomes dominated by higher order terms. We present the most recent experimental results and their interpretation as well as accompanying simulation results.
Paper: MOPA176
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPA176
About: Received: 02 May 2023 — Revised: 09 May 2023 — Accepted: 11 May 2023 — Issue date: 26 Sep 2023
MOPL018
Radiation field characterization for present LHC and future HL-LHC forward physics experiments
543
In recent years, there has been an increasing interest for experiments in the LHC complex that aim to push the frontiers of Physics, in locations that do not interfere with the normal operation of the machine while guaranteeing an acceptable signal-to-background ratio. This is the case with the Forward Search Experiment (FASER), which was approved in 2018, followed by the approval of the Scattering Neutrino Detector (SND) of the SHiP experiment in 2021. During the High Luminosity era, FASER and SND will continue to record data, for which a re-evaluation of the signal and background levels is required to prepare for the installation of the new detectors. Furthermore, there is a proposal for the construction of a Forward Physics Facility (FPF) at more than 600 m from the ATLAS interaction point to house far-forward physics experiments. These would benefit from a very low background due to the distance from the LHC tunnel and the more than 100 m of rock and concrete that serve as shielding, allowing the study of rare and exotic processes. Extensive calculations of physics signals, radiation levels and background conditions were performed by FLUKA Monte Carlo simulations and are summarized in this paper.
Paper: MOPL018
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPL018
About: Received: 02 May 2023 — Revised: 10 May 2023 — Accepted: 16 Jun 2023 — Issue date: 26 Sep 2023
MOPL021
First results of running the LHC with lead ions at a beam energy of 6.8 Z TeV
555
A two-day test of operation with Pb ion beams was carried out in the CERN Large Hadron Collider (LHC) in 2022, with the aim of gaining experience in view of the future high luminosity heavy-ion physics runs from 2023 onwards. The LHC experiments received the first Pb-Pb collisions at a record energy of 5.36 TeV centre-of-mass energy per colliding nucleon pair (beam energy 6.8 Z TeV). Bunch trains created with a new production scheme in the injectors, including slip-stacking, were injected into the LHC, with the collimation of nuclear beams with bent crystals tested along with a new collimation scheme for collision products. This paper describes the conditions and outcomes of these tests, which are critical steps in the upgrade to higher luminosity.
Paper: MOPL021
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPL021
About: Received: 02 May 2023 — Revised: 08 May 2023 — Accepted: 19 Jun 2023 — Issue date: 26 Sep 2023
MOPL035
Harmonics of 50 Hz on the beam spectrum of the Large Hadron Collider
606
Studies of the beam spectrum of the Large Hadron Collider (LHC) have revealed the existence of harmonics of the mains frequency (50~Hz), ranging from 50~Hz to 8~kHz, in the form of transverse dipolar excitations. The restart of the LHC operation in Run 3 was accompanied by substantial improvements in the beam instrumentation. In particular, the upgrade of the transverse damper’s observation system (ADTObsBox), currently providing bunch-by-bunch and continuous position measurements, allows for the first time a systematic follow-up of the harmonics’ evolution during the run. In this paper, we present parasitic observations collected during the LHC physics operation, as well as results from dedicated experiments with the aim of providing further insights into the source of the perturbation, especially concerning the 50~Hz harmonics around 8~kHz. These tests include modifications in the operation mode of systems such as some of the Uninterruptible Power Supplies, while observing potential changes in the spectrum of the beam position data.
Paper: MOPL035
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPL035
About: Received: 02 May 2023 — Revised: 06 May 2023 — Accepted: 11 May 2023 — Issue date: 26 Sep 2023
MOPL040
Experience from the US contribution to HL-LHC: Nb3Sn focusing quadrupoles and SRF crab cavities
622
The Interaction Regions (IR) of many colliders benefit from the application of leading-edge technologies to ensure the highest possible luminosity delivered to the experiments. Leading-edge low-beta focusing magnets and crab cavities to handle individual bunches are critically important to increase the instantaneous and integrated luminosity in future Colliders. The High-Luminosity LHC Upgrade, HL-LHC, with Nb3Sn Magnets (called MQXF) and Superconducting Radio Frequency (SRF) crab cavities (of two types, called DQW and RFD) is a world-wide collaborative project under construction in this decade to utilize the solutions mentioned above as key ingredients to increase tenfold the integrated luminosity delivered to the CMS and ATLAS experiments in the next decade. The HL-LHC AUP is the US effort to contribute approximately 50% of the low-beta focusing magnets and crab cavities for the HL-LHC. In this contribution we present the valuable lessons learned by the US efforts in the procurement, construction, and testing phases of the Nb3Sn focusing magnets and SRF crab cavities. We will report on the experience gathered by HL-LHC AUP in the production of the first half of deliverables (magnets MQXFA03 to MQXFA13). We will also report on the test of the first cryoassemblies and the status of the cavities’ development, production and testing. Both the technical and project management lessons-learned will inform applications of these technologies to future colliders and projects.
Paper: MOPL040
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPL040
About: Received: 01 May 2023 — Revised: 23 Jun 2023 — Accepted: 23 Jun 2023 — Issue date: 26 Sep 2023
MOPL045
Operational beta* levelling at the LHC in 2022 and beyond
642
During the third run period of the CERN Large Hadron Collider (LHC), as well as for the future High-Luminosity LHC era, luminosity levelling by beta* is a key technique to control the pile-up in the high-luminosity experiments ATLAS and CMS while maintaining Landau damping through the head-on beam-beam interaction. This implies changing the machine optics in the interaction regions while keeping high-intensity beams in collision and the experimental detectors in their data taking configuration. This contribution summarizes the implementation and operational experiences obtained during the first year of operation with beta* levelling at the LHC and provides an outlook for the following years, when the beta* levelling range will be further extended.
Paper: MOPL045
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPL045
About: Received: 21 Apr 2023 — Revised: 09 May 2023 — Accepted: 12 May 2023 — Issue date: 26 Sep 2023
MOPL048
Performance of a double-crystal setup for LHC fixed-target experiments
650
The Physics Beyond Colliders (PBC) studies at CERN address the possibility to utilise protons in the Large Hadron Collider (LHC) for a fixed-target program beyond the colliding-beam physics. As part of PBC, a double-crystal test stand is considered for installation in the LHC off-momentum collimation Insertion Region (IR) 3. In this PBC experiment, a first silicon crystal deflects beam-halo protons from the main beam onto a fixed-target. A second crystal, providing bending angles in the mrad range, is located immediately downstream of the target to deflect target-produced secondary particles onto a detector that will measure the electric and magnetic dipole moments of short-lived baryons. The LHC test stand will serve as a proof-of-principle machine experiment to assess the performance of new crystals at LHC energies and to address a number of critical machine aspects related to this complex setup. In this paper, simulations in MAD-X and SixTrack are used to predict the performance of the proposed double-crystal layout for the LHC Run 3 test stand and the LHC Run 4 final experiment.
Paper: MOPL048
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPL048
About: Received: 03 May 2023 — Revised: 08 May 2023 — Accepted: 16 Jun 2023 — Issue date: 26 Sep 2023
MOPL073
Toward a new era of spin-polarized electron beams at SuperKEKB
720
The SuperKEKB accelerator is currently in operation in Tsukuba, Japan, with a planned long shutdown in 2026. Among the possible upgrades being considered during this period is the change to a polarized electron beam in the High Energy Ring. Such a change would require modifications in the source generation and transport, geometrical and lattice variations to provide spin rotation, and polarimetry. A Polarized SuperKEKB Working Group has been formed from members of the Belle II experiment and the SuperKEKB accelerator team to investigate the possibilities and challenges of these modifications. This talk lays out the goals of the proposed upgrade, considers the necessary changes to the existing accelerator and their feasibility and lays out the physics motivation behind such an effort.
Paper: MOPL073
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPL073
About: Received: 11 May 2023 — Revised: 11 May 2023 — Accepted: 19 Jun 2023 — Issue date: 26 Sep 2023
MOPL079
Monochromatization Interaction Region Optics Design for Direct s-channel production at FCC-ee
738
One of the most fundamental measurements since the Higgs boson discovery, is its Yukawa couplings. Such a measurement is only feasible, if the centre-of-mass (CM) energy spread of the e+e- collisions can be reduced from ~50 MeV to a level comparable to the Higgs boson’s natural width of ~4 MeV. To reach such desired collision energy spread and improve the CM energy resolution in colliding-beam experiments, the concept of a monochromatic colliding mode has been proposed as a new mode of operation in FCC-ee. This monochromatization mode could be achieved by generating a nonzero dispersion function of opposite signs for the two beams, at the Interaction Point (IP). Several methods to implement a monochromatization colliding scheme are possible, in this paper we report the implementation of such a scheme by means of dipoles. More in detail a new Interaction Region (IR) optics design for FCC-ee at 125 GeV (direct Higgs s-channel production) has been designed and the first beam dynamics simulations are in progress.
Paper: MOPL079
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPL079
About: Received: 03 May 2023 — Revised: 07 May 2023 — Accepted: 15 Jun 2023 — Issue date: 26 Sep 2023
MOPL084
Beam background study at BEPCII
753
The Beijing Electron Positron Collider II will upgrade to achieve a higher beam energy and higher luminosity which need a higher beam current and smaller beam size. The consequent high beam background should be controlled within in a safety range. The beam related background at BEPCII is mainly from the Touschek effect and the beam gas effect. This paper presents the beam background study at BEPCII, which includes the recent results of experiment and simulation.
Paper: MOPL084
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPL084
About: Received: 02 May 2023 — Revised: 24 May 2023 — Accepted: 20 Jun 2023 — Issue date: 26 Sep 2023
MOPL085
DAFNE run for the SIDDHARTA-2 experiment
756
DAFNE, the Frascati electron-positron collider, based on the Crab-Waist collision scheme, has successfully completed the preliminary phase with the SIDDHARTA-2 detector aimed at testing and optimizing the performances of the machine and the experimental apparatus. In this configuration the collider has delivered to the experiment, using gaseous 4He targets, a data sample suitable to perform studies about the kaonic helium transitions with an accuracy which is the status of the art in the field. As a next step DAFNE is planning a new run finalized to deliver data to the detector in order to study the more elusive kaonic deuterium transition. In this context the setup and the performances of collider the are presented with special attention to the strategy adopted to reduce the background shower on the experimental apparatus.
Paper: MOPL085
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPL085
About: Received: 03 May 2023 — Revised: 18 May 2023 — Accepted: 23 Jun 2023 — Issue date: 26 Sep 2023
MOPL141
The CLEAR user facility: a review of the experimental methods and future plans
876
The CERN Linear Accelerator for Research (CLEAR) is a test facility delivering an electron beam in the 30-220 MeV energy range to a diverse user community. In 2022, several hardware and software upgrades were done to the main installation, and procedures and methods were developed to address specific user requirements, including a further extension of the beam parameter ranges. In the paper, these improvements are described and the experimental activities during 2022/2023 are outlined. An outlook on future potential upgrades and on the planned experimental activities in the next years is also given.
Paper: MOPL141
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPL141
About: Received: 03 May 2023 — Revised: 05 Jun 2023 — Accepted: 05 Jun 2023 — Issue date: 26 Sep 2023
MOPL170
The ESSvSB+ project
929
The European Spallation Source neutrino Super Beam plus (ESSνSB+) project has recently been approved by the EU for a 4-year design study. It aims at measuring the neutrino-nucleus cross-section, which represents the dominant systematic uncertainty in the measurement, in the energy range of 0.2 – 0.6 GeV, as well as perform searches for sterile neutrinos using a Low Energy nuSTORM (LEnuSTORM) and a Low Energy Monitored Neutrino Beam (LEMNB). ESSnuSB+ follows the ESSnuSB design study project 2019-2022 that resulted in a conceptual design of ESSnuSB and an evaluation of its high performance for leptonic CP violation measurements which is due to that the measurements will be made at the second, rather than the first, oscillation maximum, where the sensitivity of the experiment is close to 3 times higher than at the first maximum. This paper reviews the ESSnuSB design-study results and presents the planned ESSnuSB+ design study.
Paper: MOPL170
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPL170
About: Received: 08 May 2023 — Revised: 06 Jun 2023 — Accepted: 06 Jun 2023 — Issue date: 26 Sep 2023
MOPL179
A conceptual design of FFA ring for super heavy element production adopting the ERIT mechanism.
955
Production of super heavy elements of which atomic number is larger than 118 can provide new prospects in the field of nuclear physics. Extremely low production rate of these elements makes the experiments time consuming. This difficulty can be solved by using the energy recovery internal target, so-called ERIT, because the number of interactions can be increased as a circulating beam hits the target located in the ERIT ring. Here, we present a conceptual design of the FFA ring for super heavy element production adopting the ERIT mechanism.
Paper: MOPL179
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPL179
About: Received: 03 May 2023 — Revised: 25 May 2023 — Accepted: 25 May 2023 — Issue date: 26 Sep 2023
MOPL184
Multicell dielectric disk accelerating structure design and low power results
969
Utilizing short RF pulses ($\sim$9 ns) with Dielectric Disk Accelerators (DDA) is a way to improve the energy efficiency of a linear accelerator and decrease the required footprint while still achieving large energies. A DDA is an accelerating structure that utilizes dielectric disks to improve the shunt impedance while still achieving large accelerating gradients. A single cell clamped DDA structure was designed and high power tested at the Argonne Wakefield Accelerator, reaching an accelerating gradient of 102~MV/m. A multicell clamped DDA structure has been designed and fabricated. Simulation results for this new structure show a 108~MV/m accelerating gradient with 400~MW of input power with a high shunt impedance and group velocity. Engineering designs have been improved from the single cell structure to improve the consistency of clamping over the entire structure. The multicell structure has been fabricated, assembled, and low power tested with high power testing to come.
Paper: MOPL184
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPL184
About: Received: 03 May 2023 — Revised: 11 May 2023 — Accepted: 20 Jun 2023 — Issue date: 26 Sep 2023
MOPM014
Reducing floor vibration of TPS experimental hall caused by air handling units
1005
The Taiwan Photon Source (TPS) experimental facility has experienced vibration interference at approximately 16.8 Hz during experiments at the end station of the TPS 23A beamline, which was traced back to the air handling units (AHUs) located on the second floor of the outer ring area of TPS. The vibration of the AHUs not only affects the TPS beamline 23A end station but also all experimental areas. In this paper, we present two methods to reduce the floor vibration of the experimental hall caused by the AHUs. Firstly, we adjusted the operating frequency of each AHU fan to avoid resonance and reduce the vibration of the nearby experimental area floor, which can be reduced by up to 40%. Secondly, we installed additional air isolation mounts outside the AHU to further reduce the impact of the fans on floor vibrations, which resulted in a reduction of vibration transmission by about 30%. Our findings provide useful information for those dealing with vibration interference caused by AHUs and can help improve the experimental accuracy and efficiency in similar facilities.
Paper: MOPM014
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPM014
About: Received: 02 May 2023 — Revised: 08 May 2023 — Accepted: 12 May 2023 — Issue date: 26 Sep 2023
MOPM037
Investigations into operating Pulse Picking by Resonant Excitation (PPRE) in the vertical plane
1071
As preparation for the upcoming Diamond-II upgrade, provisions for timing-users (those who predominantly care about the timing characteristics of the synchrotron radiation) are being investigated. Although ‘Hybrid bunch’ modes are currently employed at Diamond, such operation presents challenges for Diamond-II that merit investigating alternative approaches. PPRE, one such approach, involves resonantly exciting a targeted electron bunch using a Transverse Multi Bunch Feedback system (TMBF). We report on the efficacy of the TMBF for driving one (or few) bunches, focusing on studying the charge-dependent effects and the achieved vertical emittance, and also by considering the effect of long range impedance between bunches. Furthermore, to test experimentally the use of PPRE, we present our first results from a representative beamline. The work is also discussed in context of the proposed operational requirements for Diamond-II.
Paper: MOPM037
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPM037
About: Received: 02 May 2023 — Revised: 11 May 2023 — Accepted: 16 Jun 2023 — Issue date: 26 Sep 2023
MOPM039
On-resonance round beam experiment in the HLS-II storage ring
1079
The strong intra beam scattering effect and the increase in horizontal emittance become common issues for next-generation ultra-low emittance storage rings. The round beam can be an effective method to solve these problems. Moreover, the produced round synchrotron radiation is suitable for optical matching. The on-resonance tune is an easier method to achieve round beam. In this paper, simulation and experimental results are introduced based on the nominal lattice of the HLS-II storage ring.
Paper: MOPM039
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPM039
About: Received: 01 Apr 2023 — Revised: 06 May 2023 — Accepted: 16 Jun 2023 — Issue date: 26 Sep 2023
MOPM059
Magnetic measurement of the magnets with trim coils in the HEPS storage ring
1125
The High Energy Photon Source (HEPS) is a 34-pm, 1360-m storage ring light source being built in the suburb of Beijing, China. In the HEPS storage ring, a proportion of quadrupoles and sextupoles are equipped with trim coils for horizontal and vertical orbit correction. For these magnets, the main field and corrector fields may have non-ignorable impact on each other. We have carried out detailed measurements and subsequent data analysis of these magnets. It is observed that changing the corrector currents in the presence of constant main current, can lead to a relative deviation of the main field of 0.1 percent level. In this paper, we will report the measurement procedure and main results.
Paper: MOPM059
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPM059
About: Received: 02 May 2023 — Revised: 19 Jun 2023 — Accepted: 19 Jun 2023 — Issue date: 26 Sep 2023
MOPM101
Status update on SUNADAE2 magnetic field test facility at European XFEL
1215
The implementation and further improvements of superconducting undulators is part of the European XFEL facility development program. Within this program, a magnetic field test facility is being developed. Named SUNDAE2 (Superconducting UNDulAtor Experiment 2), it aims to perform in-vacuum magnetic field measurements of superconducting undulators (SCUs) with three techniques: Hall probe, moving wire, and pulsed wire. This contribution presents the updates and status of SUNDAE2.
Paper: MOPM101
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPM101
About: Received: 31 Mar 2023 — Revised: 28 May 2023 — Accepted: 22 Jun 2023 — Issue date: 26 Sep 2023
MOPM123
Cavity mirror development for optical enhancement cavity of steady-state microbunching light source
1254
Optical enhancement cavity (OEC) provides the high intensity and high stability modulation laser field in steady-state microbunching (SSMB) light source. An SSMB extreme ultraviolet (EUV) light source targeted for lithography application is currently being developed at Tsinghua University, which demands for megawatt scale intra-cavity power for OEC. Cavity mirrors are the key components of the OEC to realize its designed parameters. Here we report the development progress of the cavity mirrors.
Paper: MOPM123
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-MOPM123
About: Received: 02 May 2023 — Revised: 06 Jun 2023 — Accepted: 06 Jun 2023 — Issue date: 26 Sep 2023
TUOGA1
Laser assisted charge exchange injection into the ring at the SNS
1311
A realistic laser assisted charge exchange (LACE) scheme for 1.3~GeV H- beam injection into the Ring for Spallation Neutron Source is under development. The design considered here is supposed to demonstrate the possibility of H$^-$ charge exchange injection into the SNS ring as an alternative to carbon foil stripping. A realistic stripping magnet design is considered as an integrated part of the injection area. Beam dynamics at the injection area are optimised. Laser assisted stripping, painting and beam dynamics of protons in the ring is simulated. Several alternative stripping schemes are evaluated.
Paper: TUOGA1
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUOGA1
About: Received: 04 May 2023 — Revised: 06 Jun 2023 — Accepted: 06 Jun 2023 — Issue date: 26 Sep 2023
TUOGA3
Experimental measuremnet of quadrupole beam oscillating frequency at CSNS RCS
1319
In high intensity proton synchrotrons, space charges effects will cause tune shift of the beam. When the betatron tune spreads over a resonance line, the betatron oscillation amplitude will get larger, causing large beam loss. Through the quadrupolar beam transfer function, the coherent space-charge tune shift of quadrupolar beam oscillations can be derived with quadrupole oscillating frequency. China Spallation Neutron Source (CSNS) is a high intensity accelerator based facility consists of linear accelerator and the Rapid Cycle Synchrotron (RCS). A quadrupolar BPM is already installed at RCS for obtaining quadrupolar beam oscillating information this year. This paper will present the experimental data during accelerator commissioning and how to obtain the quadrupole beam oscillating frequency on CSNS/RCS.
Paper: TUOGA3
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUOGA3
About: Received: 03 May 2023 — Revised: 08 Jun 2023 — Accepted: 08 Jun 2023 — Issue date: 26 Sep 2023
TUYG1
Overall status of the HL-LHC project
1322
The High-Luminosity LHC project aims at increasing the LHC luminosity by an order of magnitude, and support LHC operation till the early 2040s. This presentation will review the overall HL-LHC project status. Many HL-LHC achievements will be available for reporting by mid 2023, starting with the finalisation of the Civil Engineering and extending up to the triplet magnet prototype demonstration.
Paper: TUYG1
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUYG1
About: Received: 02 May 2023 — Revised: 04 May 2023 — Accepted: 25 May 2023 — Issue date: 26 Sep 2023
TUODB2
Dielectric laser acceleration for dark sector studies
1332
For the purpose of indirect search of dark matter, we designed laterally driven Dielectric Laser Acceleration (DLA) structure that achieves 1.2 MeV energy gain in 6 mm length together with 6D confinement. The design originated from a relativistic DLA structure and was supplemented with non-homogeneous shapes following the APF segments and optimized using a genetic algorithm together with the DLAtrack6D tracker. The achieved throughput could be increased to 98%.
Paper: TUODB2
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUODB2
About: Received: 03 May 2023 — Revised: 22 May 2023 — Accepted: 22 May 2023 — Issue date: 26 Sep 2023
TUOGB3
Spin transparency experiment test in RHIC
1343
A novel technique, called a spin transparency mode, for preservation and control of electron and ion spin polarization in colliders and storage rings has been proposed. The beam polarization can then be fully controlled by small adjustments of the snake axis orientations and snake strengths. An experiment has been carried out recently to test the concept. One of the RHIC rings is set to be “transparent” to the spin by making the axes of its two Siberian snakes nearly parallel. The polarization was rotated from vertical to radial and from up to down by varying the snake currents. This paper summarizes the recent experiment results and discusses the comparison with simulations.
Paper: TUOGB3
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUOGB3
About: Received: 02 May 2023 — Revised: 12 May 2023 — Accepted: 16 Jun 2023 — Issue date: 26 Sep 2023
TUPA001
Copper surface treatment with deep UV ultrafast laser for improved photocathode photoemissive properties
1350
Surface nanostructuring is a promising approach when it comes to improving the quantum efficiency (QE) of materials for electron accelerator purposes at CERN. This is due to the plasmonic effect taking place in metallic materials at the nanoscale, when an electromagnetic wave interacts with a sub-wavelength feature. Ultrafast laser surface nanopatterning can be an efficient and times saving method for producing such nanostructures. We conducted a study of nanostructuring of copper surfaces with a deep-UV femtosecond laser. A wide range of fabrication parameters (speed, laser fluence and repetition rate) were tested. At different energy regimes we were able to produce Laser Induced Periodic Surface Structures (LIPSS), as well as spherical nanoparticles of tunable size and other types of periodic nanoscale features. Sub-wavelength periodic structures yield higher exaltation of surface plasmons under matching excitation wavelength, resulting in a potentially significant increase in QE of copper photocathodes. Moreover, by using the same laser source for nanomachining and photoemission, one can easily integrate the technology in and existing photoinjector.
Paper: TUPA001
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPA001
About: Received: 13 May 2023 — Revised: 22 May 2023 — Accepted: 22 May 2023 — Issue date: 26 Sep 2023
TUPA030
Mean Transverse Energy and Degradation Measurements on a Caesium Telluride Photocathode
1404
Fourth generation light sources require high brightness electron beams. To achieve this a cathode with a high quantum efficiency and low intrinsic emittance is required while also being robust with a long lifetime and low dark current. Alkali-metal photocathodes have the potential to fulfil these requirements and, as such, are an important area of research for the accelerator physics community. A Cs-Te photocathode grown at STFC Daresbury Laboratory is presented. Important photoemissive properties such as quantum efficiency (QE), mean transverse energy (MTE) and lifetime have been investigated using the Transverse Energy Spread Spectrometer (TESS). Elevated MTE beyond the Cs$_2$Te photoemission threshold is reported as well the QE decrease and MTE increase when a Cs-Te photocathode is subject to progressive oxygen degradation.
Paper: TUPA030
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPA030
About: Received: 02 May 2023 — Revised: 09 May 2023 — Accepted: 16 Jun 2023 — Issue date: 26 Sep 2023
TUPA034
High-power experiment of a C-band photocathode gun
1412
The C-band electron gun is an attractive option for lower emittance with compactness. In this paper, a new C-band photocathode gun has been developed. The electron gun experienced a high-power test and had preliminary reached the designed gradient on the cathode. The high-power test results are the basis of the beam dynamics design and beam testing.
Paper: TUPA034
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPA034
About: Received: 08 May 2023 — Revised: 09 May 2023 — Accepted: 19 Jun 2023 — Issue date: 26 Sep 2023
TUPA076
Design and test of a metamaterial accelerating structure for Wakefield acceleration
1496
Structure-based wakefield acceleration with nanosecond-long RF pulses is a promising advanced accelerator concept to mitigate the risks of RF breakdown. Advanced structures are required to satisfy the need of a high transient gradient with a short pulse length. A metamaterial (MTM) structure, as a subwavelength periodic structure exhibiting a negative group velocity, could have a higher shunt impedance, thus a higher gradient, compared to structures with the same but positive group velocities. An X-band ‘wagon wheel’ structure has been designed and tested as an accelerating structure for two-beam acceleration. Up to 200 MV/m of gradient has been achieved with an input power extracted from the 65 MeV drive beam at AWA, with a peak power of 115 MW, and a pulse length of 6 ns (FWHM). Evidence has been found towards a new accelerating regime, the breakdown insensitive accelerating regime (BIAR), where breakdown was only observed in the secondary pulse of the transmitted RF signal while the primary pulse (useful for acceleration) was not interrupted. This experiment could lead to high-gradient wakefield acceleration and new knowledge in the breakdown physics in the short-pulse regime.
Paper: TUPA076
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPA076
About: Received: 03 May 2023 — Revised: 19 May 2023 — Accepted: 20 Jun 2023 — Issue date: 26 Sep 2023
TUPA080
Demonstration of transverse stability in an alternating symmetry planar dielectric structure
1502
Dielectric wakefield acceleration (DWA) is a promising approach to particle acceleration, offering high gradients and compact sizes. However, beam instabilities can limit its effectiveness. In this work, we present the result of a DWA design that uses alternating gradients to counteract quadrupole-mode induced instabilities in the drive beam. Through simulation and experimental results, we show that this approach is effective at suppressing beam breakup, allowing for longer accelerating structures. We have designed and fabricated a new apparatus for positioning the DWA components in our setup. This allows us to precisely and independently control the gap in both transverse dimensions and consequently the strength of the destabilizing fields. Our results show that the use of alternating gradient structures in DWA can significantly improve its performance, offering a promising path forward for high-gradient particle acceleration.
Paper: TUPA080
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPA080
About: Received: 03 May 2023 — Revised: 10 May 2023 — Accepted: 11 May 2023 — Issue date: 26 Sep 2023
TUPA086
A positron source demonstrator for future colliders
1518
Regarding high current e+ sources, the almost universal usage of target-based production schemes combined with conventional capture technology has led to poor transmission efficiencies. This long-standing difficulty to handle the extreme e+ transverse emittance and energy spread has been a major impediment for future, high luminosity lepton collider designs. The PSI Positron Production (P-cubed or P$^3$) experiment, framed in the FCC-ee study, is a demonstrator for a e+ capture system with potential to improve the state-of-the-art e+ yield by an order of magnitude. The experiment will be hosted at the SwissFEL facility at PSI as of 2025, where installation works are ongoing. This paper is an overview of P$^3$, with a particular focus on the novel capture system and its effects on the beam dynamics. A concept for the experiment diagnostics is also introduced.
Paper: TUPA086
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPA086
About: Received: 26 Apr 2023 — Revised: 05 Jun 2023 — Accepted: 05 Jun 2023 — Issue date: 26 Sep 2023
TUPA114
Extraction of high-charge state neon and krypton from the D-Pace Penning ion source test stand
1574
D-Pace has a self-heated hot-cathode Penning ion source test stand at their Ion Source Test Facility (ISTF). High-charge state production of boron, arsenic, and phosphorous is interesting to the ion implantation industry, as it allows for higher energy implants of these dopants using the same accelerating gradient in a given accelerator system. We use Neon and Krypton as proxy gases to investigate whether the Penning ion source could be used for high-charge state production in ion implanters. We were able to produce charge states up to Ne$^{3+}$ ($>$ 200 $e \mu$A) and Kr$^{6+}$ ($>$ 7 $e \mu$A). The obstacles in using the current Penning ion source test stand are discussed, with comments on how to potentially increase the current output, stability, and lifetime of this ion source.
Paper: TUPA114
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPA114
About: Received: 27 Apr 2023 — Revised: 11 May 2023 — Accepted: 23 Jun 2023 — Issue date: 26 Sep 2023
TUPA132
Ultra thin Cs3Sb photocathodes with anomalously high quantum efficiency
1605
In this proceeding, we demonstrate the synthesis of epitaxial Cs$_3$Sb films with a high degree of crystallinity on silicon carbide substrates. Films less than 10 nm thin are grown in vacuum and exhibit percent level quantum efficiencies at 532 nm. We find a positive correlation between quantum efficiency and improved crystallinity of the photocathode film, particularly in the longer wavelengths of the visible spectrum. We present a model describing the optical interference effects observed in the SiC - Si substrate multilayer that enhance quantum efficiency of the thin film photocathodes by almost a factor of two at particular wavelengths. Additionally, we characterize the surface and bulk crystallinity of epitaxial Cs$_3$Sb films using both X-ray diffraction (XRD) and reflection high energy electron diffraction (RHEED) in an endeavor to identify relationships between crystalline phases and photocathode performance.
Paper: TUPA132
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPA132
About: Received: 05 May 2023 — Revised: 19 May 2023 — Accepted: 22 Jun 2023 — Issue date: 26 Sep 2023
TUPA154
Project management structures, processes, and tools for the HL-LHC project
1656
At its restart after a major shutdown in 2029, the LHC will see its interaction regions upgraded by the installation of the HL-LHC equipment, with new Nb3Sn triplets and cold powering system, crab-cavities for crossing angle compensation and luminosity levelling, an upgraded collimation system, and fully remote alignment for the final focusing region. In the following operational runs, the LHC will aim at a tenfold increase of the integrated luminosity compared to the original design. The HL-LHC project features a light project management (PM) structure, with strong delegation of PM tasks to the 19 work-packages structuring the project by expertise areas. Unified processes align the community around a common configuration and performance, while shared tools are applied to budget and schedule management . The paper describes committees and processes applied to run this complex project, within the overall organization and planning of CERN. We explain the procedures ruling decisions and change management in configuration, cost and schedule, detail the responsibility share between project and work-packages and explain how quality standards build a common language across the project.
Paper: TUPA154
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPA154
About: Received: 02 May 2023 — Revised: 08 May 2023 — Accepted: 11 May 2023 — Issue date: 26 Sep 2023
TUPA157
SPS fixed target spill quality improvements in the longitudinal plane
1667
The SPS proton fixed target beams are spilled via a third integer resonant extraction, for which high momentum spread is beneficial. To increase the momentum spread prior to the slow extraction, the bunches are stretched at the unstable phase by inverting the sign of the RF voltage. The RF phase is then flipped back, and the voltage is turned off when the bunch distribution is rotated to the maximum momentum spread. The past production scheme additionally relied on uncontrolled longitudinal blow-up of the unstable beam during the acceleration ramp. After the major upgrade of the main RF system and a successful impedance reduction campaign, the spill quality was significantly compromised. This contribution summarizes the efforts to recover, and improve, the spill quality. The use of the fourth harmonic RF system and controlled longitudinal emittance blow-up are used for beam stabilization along the ramp. Moreover, RF counter phasing is applied during the first part of the de-bunching to profit from the cavity impedance reduction of the feedback systems.
Paper: TUPA157
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPA157
About: Received: 01 May 2023 — Revised: 16 May 2023 — Accepted: 19 Jun 2023 — Issue date: 26 Sep 2023
TUPA163
SIS18 operation and recent development
1683
SIS18 will be used as booster for FAIR’s main synchrotron SIS100. In addition, it provides a wide variety of ions from Protons to Uranium for users directly at GSI and FAIR. An upgrade program to enhance the overall performance for the booster operation has been carried out. Part of the upgrade program for booster operation was a complete overhaul of the control system including data supply and timing system. In addition, a new magnetic alloy cavities have been installed for h=2 operation and dual harmonic operation in conjunction with the existing H=4 cavities. The main power supplies have been upgraded to allow reduced cycle times. The vacuum system has been significantly enhanced. Further upgrades and machine studies have been performed to enhance available beam parameters and provide new features for the users. We will report about machine studies and recent operation for FAIR Phase0 experiments utilizing various upgrade measures to enhance overall machine performance.
Paper: TUPA163
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPA163
About: Received: 03 May 2023 — Revised: 08 May 2023 — Accepted: 11 May 2023 — Issue date: 26 Sep 2023
TUPA180
Accelerator and beam physics challenges in support of FRIB experiments
1729
The Facility for Rare Isotope Beams (FRIB), a major nuclear physics facility for research with fast, stopped, and reaccelerated rare isotope beams, started operation in May 2022. Since then, five nuclear physics experiments have been successfully accomplished. The experiments with rare isotope beams typically last within 1-2 weeks. Each experiment requires a different primary beam and its energy. It is critical to shortening the accelerator and fragment separator setup time to meet the requirements of the FRIB Users community. Currently, the primary focus in the linac is to reduce the accelerator setup time and ramp up beam power. Many physics applications, including Machine Learning, have been developed and used to set up the accelerator and beamlines. The simultaneous acceleration of multiple charge states of heavy ion beams is routinely used to minimize the beam power deposition on the charge selector slits after the stripper. The challenges in the fragment separator are related to the highly non-linear beam physics due to the large emittance and momentum spread of the isotope beams. Since the iron-dominated SC magnets operate near saturation, the optimization process includes field distributions at different excitation currents. This paper discusses the theoretical and experimental procedures to improve the linac and fragment separator performance.
Paper: TUPA180
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPA180
About: Received: 28 Apr 2023 — Revised: 12 May 2023 — Accepted: 12 May 2023 — Issue date: 26 Sep 2023
TUPA192
Strategies for SPIRAL2 linac heavy-ion beam tuning
1762
Heavy ions have been accelerated for the first time by SPIRAL2 in 2022. A fast method to tune the linac cavities has been used (< 1 hour by now, < 10’ in the future) to obtain a 7 MeV/A 18O6+ beam (50 microA CW). Then an automatic Q/M beam change procedure has been successfully used to directly produce a 18O7+ beam. The goal was to demonstrate the possibility to tune a beam even if its intensity is too low (<10 microA) to be seen by phasemeters (BPM) along the linac. The linac transmission was ~ 100% for both beams and, as expected, the measured output energy was the same. The same oxygen reference beam tuning has been also used to obtain 80 microA of 40Ar14+ at 7 MeV/A. Again, the same method has been used to tune the linac cavities at the RFQ output energy beam (0.73 MeV/A, no acceleration). These different methods and the one used to tune the linac output energy are presented.
Paper: TUPA192
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPA192
About: Received: 03 May 2023 — Revised: 06 May 2023 — Accepted: 11 May 2023 — Issue date: 26 Sep 2023
TUPL062
Multi-color operation via coherent harmonic generation in a plasma driven attosecond X-ray source
1896
The ongoing Plasma-driven Attosecond X-ray source experiment (PAX) at FACET-II aims to produce coherent soft X-ray pulses of attosecond duration using a Plasma Wakefield Accelerator [1]. These kinds of X-ray pulses can be used to study chemical processes where attosecond-scale electron motion is important. For this first stage of the experiment, PAX plans to demonstrate that <100 nm bunch length electron beams can be generated using the 10 GeV beam accelerated in the FACET-II linac and using the plasma cell to give it a percent-per-micron chirp. The strongly chirped beam is then compressed in a weak chicane to sub-100nm length, producing CSR in the final chicane magnet at wavelengths as low as 10s of nm. In this contribution we describe the results expected from this initial setup, as well as future iterations of the experiment in which we plan to use short undulators to drive coherent harmonic generation to produce attosecond, terawatt X-ray pulses down to 1-2 nm. In addition to PAX, a similar ongoing experiment at the XLEAP beamline at LCLS-II plans to demonstrate GW-scale attosecond pulses at UV wavelengths. We discuss tapering strategies which enable precise tuning of the XUV bandwidth and the generation of few-cycle micron wavelength pulses in this experiment which can be used for time-synchronized attosecond pump-probe experiments. [1] C. Emma, X.Xu et al APL Photonics 6, 076107 (2021)
Paper: TUPL062
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPL062
About: Received: 08 May 2023 — Revised: 10 May 2023 — Accepted: 20 Jun 2023 — Issue date: 26 Sep 2023
TUPL131
Recent experimental results on the particle driven acceleration at the SPARC_LAB test facility
2038
Plasma accelerators are emerging as formidable and innovative technology for the creation of table-top devices thanks to the possibility to sustain several GV/m accelerating gradients at normal conducting temperature. Among others, the particle-driven configuration has been successfully tested at the SPARC_LAB test facility also demonstrating the emission of plasma-based FEL radiation in SASE and seeding operation. Recently we have performed further experimentals devoted to heightening the accelerating gradient in the plasma. The so-called comb beam has been set up with a 500pC driver followed by a 50pC trailing bunch. The maximum measured energy gain in the plasma has been of almost 30 MeV turning in an accelerating gradient of the order of 1.2 GV/m. The result represents a fundamental achievement also looking at the forthcoming EuPRAXIA@SPARC_LAB plasma-based user facility. Further experimental runs are planned for the next year on the measurements of transverse quality of the electron beam and its eventual preservation. The paper reports on the obtained experimental results and on the numerical studies for the next future experiment at the SPARC_LAB test-facility.
Paper: TUPL131
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPL131
About: Received: 19 Apr 2023 — Revised: 05 Jun 2023 — Accepted: 22 Jun 2023 — Issue date: 26 Sep 2023
TUPM040
Pre-experiment of 70 MeV H- cyclotron for producing ISOL RI beam
2289
The RAON ultra-low energy experiment team decided that the first experiment was to accelerate the proton 70 MeV using a cyclotron and collide with the SiC target to generate a radioactive isotope beam. Before this experiment, a preliminary experiment was conducted to confirm the exact location and shape of the proton beam before directly colliding with the target to generate a lot of radiation or prevent the loss of the target. The pre-experiment was done to understand the characteristics of the proton beam at the target position by configuring the faraday cup, wire grid, collimator, and slit inside the proton module. The beam current was from 1~1.5 μA, and the beam size was confirmed under the slit size 2˟2 cm2.
Paper: TUPM040
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPM040
About: Received: 10 May 2023 — Revised: 06 Jun 2023 — Accepted: 06 Jun 2023 — Issue date: 26 Sep 2023
TUPM046
Study for space charge effect in tune space at CSNS-II/RCS
2299
CSNSII is an upgrade project of China Spallation Neutron Source (CSNS), which needs to increase the beam power from 100kW to 500kW. In order to find a suitable working point area in advance and evaluate the influence of space charge effect on CSNSII, the measurements of beam loss with different tunes on CSNS was carried out and beam loss simulation in transverse tune space on CSNSII has been performed using PyORBIT code. We gave the relationship between the beam survival rate and the working point, compared four groups of candidate working points and confirmed the influence of the fourth-order resonance on the beam through the single particle model.
Paper: TUPM046
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPM046
About: Received: 03 May 2023 — Revised: 08 May 2023 — Accepted: 12 May 2023 — Issue date: 26 Sep 2023
TUPM064
Transverse characterization of 1 MeV/n RFQ output beam at Komac
2342
A 1 MeV/n Radio-Frequency Quadrupole (RFQ) has been developed and commissioned at Korea Multipurpose Accelerator Complex (KOMAC). The RFQ is designed to accelerate ions with mass to charge ratio up to 2.5. The designed peak current is 10 mA with 10 % duty factor. Currently we are utilizing the RFQ as a test bench for the reliable operation of the 100 MeV proton linac operational at KOMAC since 2013. The test bench has two beamlines installed with beam transport optics, diagnostics and irradiation chambers. We performed a quad scan experiment using a wire scanner installed in the beamline to obtain beam emittance and Twiss parameters at the entrance of the scanning quadrupole magnet. From these value, we calculated the beam emittance and Twiss parameters at the exit of the RFQ. In this paper, we report the current status of the RFQ test bench, the quad scan result and the characterization results of the 1 MeV/n RFQ output beam at KOMAC.
Paper: TUPM064
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPM064
About: Received: 03 May 2023 — Revised: 10 May 2023 — Accepted: 11 May 2023 — Issue date: 26 Sep 2023
TUPM070
Kaon beam simulations employing conventional hadron beam concepts and the RF separation technique at the CERN M2 beamline for the future AMBER experiment
2357
The future AMBER experiment aims to measure the inner structure and the excitation spectra of kaons with a high intensity kaon beam at the CERN secondary beam line M2. One way to identify the small fraction of kaons in the available beam is tagging with the help of differential Cherenkov detectors (CEDARs), whose detection efficiency depends critically on the beam parallelism. In the framework of the Conventional Beams Working Group of the Physics Beyond Colliders Initiative at CERN, several possible improvements of the conventional beam optics have been studied, trying to achieve a better parallelism, investigating especially the reduction of multiple scattering. Additionally, with the aim of increasing the Kaon purity of the beam, a Radio-Frequency separation technique has been also studied. This method exploits the differences in velocity due to the particle mass in the beam, kicking out unwanted particles with the help of two RF cavities. The limitations posed by the beam line for intensity and purity will be presented along with preliminary results of the potential purity and intensity reach of the RF-separated beam. Finally, the RF-separated beam is compared with the conventional hadron beam in terms of potential physics reach.
Paper: TUPM070
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPM070
About: Received: 01 Apr 2023 — Revised: 06 Jun 2023 — Accepted: 06 Jun 2023 — Issue date: 26 Sep 2023
TUPM071
Muon background minimisation using the second achromat of the NA62-BD experiment
2361
The K12 beam line and NA62 experiment in the North Area at CERN in beam dump mode exploits the interactions of 400 GeV protons with a movable dump-collimator, the so-called XTAX. Such interactions are theorised to generate potential light dark matter candidates such as the axion. Any rare process search requires precise knowledge and experimental reduction of the predominant muon background. A previous examination has been performed successfully, involving tuning the magnetic fields of the first achromat in K12. This contribution aims to explore further improvements using similar methods on the second achromat in the same K12 beam line, using BDSIM simulation software.
Paper: TUPM071
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPM071
About: Received: 03 May 2023 — Revised: 23 Jun 2023 — Accepted: 23 Jun 2023 — Issue date: 26 Sep 2023
TUPM074
PLAN - from LS2 to RUN3-LS3 and outcomes from the first RUN3-LS3 PLAN exercise
2367
The CERN-wide coordination of the programmed stops requires a tool to centralize and collect all the activities at a macroscopic scale. It includes the activities foreseen during Long Shutdowns (LS) and Year End Technical Stops (YETS). The CERN tool named PLAN centralises all the activities foreseen by the Groups, to have a global strategic view, assessing priorities across CERN. Thanks to the tool, arbitration processes are possible with Programmed Stops coordination, Groups and Departments. The LS2 (2018-2022) experience and the similarity of needs made the PLAN tool the obvious choice to fulfill this function for the period following the LS2. However, this tool needs some significant changes to be adapted to the constraints defined by the Run3 (2022-2025) programmed stops and previous Shutdown completion (LS2). The paper will describe the methodology to define the changes, the improvements implemented, and future developments, to support more effectively the CERN-wide coordination.
Paper: TUPM074
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPM074
About: Received: 03 May 2023 — Revised: 23 May 2023 — Accepted: 23 May 2023 — Issue date: 26 Sep 2023
TUPM076
Determination of the invariant spin axis in a COSY model using Bmad
2375
The matter-antimatter asymmetry might be understood by investigating the EDM (Electric Dipole Moment) of elementary charged particles. A permanent EDM of a subatomic particle violates time reversal and parity symmetry at the same time and would be, with the currently achievable experimental accuracy, an indication for further CP violation than established in the Standard Model. The JEDI-Collaboration (Juelich Electric Dipole moment Investigations) in Juelich has performed a direct EDM measurement for deuterons with the so called precurser experiments at the storage ring COSY (COoler SYnchrotron) by measuring the invariant spin axis. In order to interpret the measured data and to disentangle a potential EDM signal from systematic effects in the radial part of the invariant spin axis, spin tracking simulations in an accurate simulation model of COSY are needed. Therefore a model of COSY has been implemented using the software library Bmad. Systematic effects were considered by including element misalignments, effective dipole shortening, longitudinal fields and steerer kicks. These effects rotate the invariant spin axis in addition to the EDM and have to be analyzed and understood. The most recent spin tracking results as well as the methods to find the invariant spin axis will be presented.
Paper: TUPM076
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPM076
About: Received: 08 May 2023 — Revised: 09 May 2023 — Accepted: 15 Jun 2023 — Issue date: 26 Sep 2023
TUPM077
Studies of the spin coherence time of protons at COSY
2379
The search for the Electric Dipole Moments (EDM) of charged particles in storage rings necessitates polarized beams with long Spin Coherence Time (SCT) of the circulating beam. The SCT is the time during which the RMS spread of the orientation of spins of all particles in the bunch reaches one radian. A long SCT is needed to observe the coherent effect of a polarization build-up induced by the EDM. For deuterons a SCT of 1000 s has been achieved at the COoler SYnchrotron COSY (Jülich, Germany). Accomplishing such long SCT for protons is far more challenging due to their higher anomalous magnetic moment, but essential for the planned EDM experiments. It has been shown that for protons, the SCT is strongly influenced by nearby intrinsic and integer spin resonances. The strengths of the latter have been calculated for a typical optics setting of COSY and the overall influence on the SCT was predicted. In addition, the efficiency of proton spin flipping with an RF-solenoid from initially vertical direction into the ring plane is also investigated.
Paper: TUPM077
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPM077
About: Received: 19 Apr 2023 — Revised: 09 May 2023 — Accepted: 15 Jun 2023 — Issue date: 26 Sep 2023
TUPM086
SEISM: 60 GHz ECR ion source for future accelerator
2406
ECR ion sources produce ion beams with an intensity proportional to the heating frequency. SEISM (Sixty gigahErtz Ion Source using Megawatt magnets) is a unique source operating at the record frequency of $60~GHz$ thanks to a gyrotron producing high intensity HF pulse (up to $300~kW$). The prototype is based on a simple magnetic geometry, the cusp, using polyhelix coils (developed with the LNCMI, Grenoble) to generate a closed ECR surface at $2.1~T$. Since 2019, several experimental campaigns were carried out with helium and argon beams and production of ion current densities of $1~A/cm^2$) were achieved. The transport of high intensity beam is studied thanks to the dedicated transmission line and qualified with emittance measurements using a pepperpot device. Using several support gases, plasma studies are also carried out as function of source parameters such as extraction high voltage, gas pressure, bias disc potential. The dynamic of the afterglow pics is also investigated. Recent experimental results, short- and long-term research plans as well as technological choices (metal 3D printing) will be presented to transform this high current density into a high intensity ion beam that can be used for the accelerators of the future.
Paper: TUPM086
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPM086
About: Received: 03 May 2023 — Revised: 12 May 2023 — Accepted: 22 Jun 2023 — Issue date: 26 Sep 2023
TUPM094
Investigation of micro spill in RF KO extraction using tailored excitation signals
2427
Radio Frequency Knock Out (RF KO) extraction is used to extract stored particle beams from synchrotrons through transverse excitation, delivering spills of particles for experiments and medical therapy. Minimizing the fluctuations of spill intensity is vital to prevent detector pile-up and interlocks while making most efficient use of the extracted beam. To improve the spill quality, different excitation signals with characteristic frequency spectra are explored. Results of experimental studies at the Heidelberg Ion Beam Therapy Center (HIT) are presented. These demonstrate the possible improvements by tuning multi-band spectra at different harmonics. Particle tracking simulations of the slow extraction process at HIT are used to understand how different excitation signals influence the spill quality.
Paper: TUPM094
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPM094
About: Received: 02 May 2023 — Revised: 07 May 2023 — Accepted: 15 Jun 2023 — Issue date: 26 Sep 2023
TUPM100
Focusing of highly charged ion beams using Gabor-lenses
2447
A Gabor-lens is an ion optical device using the electric self-field of a stable confined electron column providing the focusing strength. This lens type was investigated in detail and it was shown that it is possible to use it in a LEBT for intense heavy ion beams. The homogeneous electron density results in linear focusing forces and provides space charge compensation of the beam. On the other hand it is not clear, how the charge state changes when a highly charged ion beam passes the pure electron plasma confined in a Gabor-lens. Therefore, an experiment was designed, which enables the possibility to transport an 15keV Ar8+-beam through a Gabor-lens and estimate the collisional three-body (e – e – ion) recombination to lower charge states. A variation of the relative velocity of the beam with respect to the electron plasma was performed and it was possible to measure the electron density at the same time. Experimental results are presented and future strategies for the transport of highly charged intense ion beams are discussed.
Paper: TUPM100
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPM100
About: Received: 03 May 2023 — Revised: 07 May 2023 — Accepted: 15 Jun 2023 — Issue date: 26 Sep 2023
TUPM101
Mutual interaction of 2m long electron plasma ensembles with an ion beam in MeV range
2451
Gabor-lens 2000 (GL2000) is an hadron optic device which confines a 2m long electron cloud. This opens up new possibilities in research with very long confined static electron ensembles. Due to the optimization of technical design it was possible to successfully complete the conditioning process creating a stable confinement of electrons. Also, the diagnostic tools were extended and the control and measurements was automated. This made it possible to scan a large parameter space with varying the external confinement parameters magnetic field, potential and residual gas pressure. In addition, numerical models of GL2000 confinement parameters were simulated to derive the operation function for different production and loss mechanisms at different potential and magnetic field settings. This should make it possible to adjust the particle ensemble within the Gabor-lens (GL) in a way, that the plasma state is defined. For applications of GLs in transport channels, particle accelerators or final focus sections it is than possible to create a perfect linear mapping of the beam and therefore a smooth focusing with space charge compensation. Using the TraceWin tool, simulations were made for beam transport through high energy beam transport lines. In addition, GL2000 was implemented to the Van-de-Graaf beamline at IKF*, to be able to investigate beam-cloud interactions and perform first transport measurements.
Paper: TUPM101
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPM101
About: Received: 03 May 2023 — Revised: 12 May 2023 — Accepted: 19 Jun 2023 — Issue date: 26 Sep 2023
TUPM102
Improvement of beam transport in high energy transfer lines using Gabor-lenses
2455
Transfer lines provide the beam transport from accelerators to experimental areas. In the study presented in this paper, commonly used beam optics are supplemented by Gabor-lenses (GL) to investigate their effect on the luminosity for fixed-target experiments. With GLs it is possible to confine a pure electron plasma with densities up to 10E15 m-3. The self-field of the homogeneous electron density provides a focal strength, whereas the space charge forces of the beam are fully compensated. The performance of GLs was numerically investigated in the GeV range (p, $\pi$+, K+) in the past. The weak but continuous radial focusing improved the acceptance of the whole transfer line. The preparation of the experiments is planned in two steps. First, a GL (GL2000) which provides a 2m long electron column was commissioned successfully at the Van-de-Graaf beam line at Institute of Nuclear Physics of Goethe-University. Beam transport measurements to investigate the stability of the confined electron column were performed using He+, Ar+ and Xe+ beams in an energy range of 0.5-2MeV. In a second step the implementation of several GLs in an existing transfer line at GSI Darmstadt was investigated numerically. The beam transport simulations using TraceWin shall take into account, that existing focusing devices and beam instrumentation should not be affected by the implementation. This enables the possibility to provide and compare the beam transport with and without electron atmosphere.
Paper: TUPM102
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPM102
About: Received: 01 Apr 2023 — Revised: 07 May 2023 — Accepted: 12 May 2023 — Issue date: 26 Sep 2023
TUPM115
Phase space painting of a self-consistent Danilov distribution in the SNS ring
2483
The {2, 2} Danilov distribution is self-consistent — it is a Vlasov equilibrium distribution that produces linear space charge forces. Additionally, the distribution has zero (four-dimensional) transverse emittance. Thus the Danilov distribution may be of use for overcoming space charge limitations at high intensities, increasing collider luminosity, or pushing the limits of transverse bunch compression using round-to-flat transformers. When such a distribution is matched to one of the eigenmodes of a ring it is possible to use phase space painting to build the distribution over many turns, maintaining self-consistency throughout. This provides a way to create high-intensity beams with unique properties that could increase accelerator performance, with direct implication for experiments. Here we report on the results of a proof-of-principle experiment using the flexible transverse phase space painting system at the Spallation Neutron Source to demonstrate the creation of an approximate Danilov distribution, including the effect of recently installed solenoid magnets.
Paper: TUPM115
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPM115
About: Received: 03 May 2023 — Revised: 23 May 2023 — Accepted: 23 May 2023 — Issue date: 26 Sep 2023
TUPM122
Design development and R&D for CERN’s HL-LHC external beam dump
2510
The energy contained in the LHC's two beams must be safely absorbed in external beam dumps (TDE). High Luminosity (HL) is a future upgrade which will increase this stored energy to 700 MJ, compared to 150 MJ in Run 1. The TDE design has changed little since Run 1; it is a cylindrical stainless-steel vessel with a core made of graphite. During long shutdown 2 (LS2), upgrades were made to the TDEs to address issues found during Run 2 and to prepare for the higher intensity of Run 3. Further upgrades will be needed for HL, due to three key challenges, i.e., a) increased vessel vibration will lead to higher stresses; b) graphitic materials able to withstand energy densities up to 5.7 kJ/g (as determined by FLUKA Monte Carlo simulations) are required; c) a new TDE cooling system is necessary, so that temperature build up following consecutive dumps will not affect the LHC’s availability. This paper describes work completed to develop a conceptual design of the HL TDE and the planned future work. Results of Finite Element (FE) simulations of the TDE’s response to the beam energy deposition and Computational Fluid Dynamics (CFD) simulations of the cooling system will be presented.
Paper: TUPM122
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-TUPM122
About: Received: 03 May 2023 — Revised: 09 May 2023 — Accepted: 19 Jun 2023 — Issue date: 26 Sep 2023
WEODB3
Understanding the beam quality requirement for high energy electron microscopy
2609
Commercial electron microscopes with a few hundred keV energies are fundamental tools for understanding the micro- to nano-scale world. One of the frontiers in electron microscopy development is to push the beam energy to MeV range to achieve improved lateral resolution for thick samples. Here we show the theoretical and preliminary experimental analysis of the electron beam quality required in the imaging and diffraction processes with different beam energy. By correlating the diffraction and imaging modalities, we use the focused beam scheme to characterize the beam emittance of a 200 keV TEM and a MeV UED. The quantitative correlation between the measured emittance and the obtained image resolution are established. This work demonstrates a characterization technique for electron microscopy and provides a guidance for designing a MeV electron diffraction and imaging beamline.
Paper: WEODB3
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEODB3
About: Received: 01 May 2023 — Revised: 06 Jun 2023 — Accepted: 06 Jun 2023 — Issue date: 26 Sep 2023
WEPA049
Microwave driven space-charge compensation with optical diagnostics and feedback
2767
A system is being developed for the maintenance of a space-charge neutralising plasma from the residual gas within the LEBT of the Front End Test Stand (FETS) at UKRI-STFC Rutherford Appleton Laboratory. Space-charge neutralisation will occur when an ion beam is allowed to collide with and ionise a background gas with pressure greater than 10-4 Torr in the presence of a solenoid fringe field, neutralisation can mitigate excess beam loss and reduce the need for beam chopping. To maintain a low density plasma between pulses, S-Band (3.4 GHz) microwaves will be injected into a LEBT cavity situated between solenoids. In order to provide sufficient microwave power to the cavity a two stage amplification system will be employed, with each stage providing a gain of 10 dB. A novel high-speed, low light-level optical diagnostics system based on Silicon Photomultiplier MPPC’s will be used in combination with a directional coupler for forward and reverse RF power measurement to provide feedback about the state of the plasma within the cavity. An overview of the design of this system will be presented along with preliminary test results.
Paper: WEPA049
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPA049
About: Received: 05 May 2023 — Revised: 22 May 2023 — Accepted: 22 May 2023 — Issue date: 26 Sep 2023
WEPA060
Beam-beam long-range wire compensators in LHC Run 3
2789
Beam-beam effects are known to undermine the performance of the LHC during proton-proton collisions. In order to enhance the luminosity production and increase the tolerance of the working point of the machine after the High Luminosity upgrade of the LHC, it is relevant to study the possibility of using current-carrying wires to compensate long-range beam-beam effects. Following proof of principle studies in LHC Run 2, beam-beam wire compensators embedded in the collimators of the LHC are used in standard operation since the start of Run 3. In this paper, a figure of merit quantifying the efficiency of luminosity production is introduced and measurements from LHC Run 3 are presented. Bunch-by-bunch data is used to demonstrate the successful compensation of beam-beam effects in the LHC.
Paper: WEPA060
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPA060
About: Received: 03 May 2023 — Revised: 10 May 2023 — Accepted: 19 Jun 2023 — Issue date: 26 Sep 2023
WEPA109
Parallel prediction of beam spot with neural networks and PCA at TTX
2908
At TTX, we try to use machine learning to give the virtual detection of the beam spot. The prediction of beam spot is difficult when the dimension becomes larger. We try to use PCA to make it smaller and use Neural networks to predict it. However, the weight of different dimension varies widely. We predict them parallel and get good results with easy neural networks.
Paper: WEPA109
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPA109
About: Received: 19 Apr 2023 — Revised: 11 May 2023 — Accepted: 22 Jun 2023 — Issue date: 26 Sep 2023
WEPA117
Improved waveforms for barrier-bucket systems
2928
Barrier-Bucket (BB) systems provide a method to apply a short gap to a coasting beam. This is utilized for different applications, like ion cleaning, or to compensate the medium energy loss caused by internal experiments. BB-cavities are broadband cavities, and the applied signal is commonly a short sine burst, followed by a flat section at zero voltage. Since the transfer function of the BB-system is usually neither flat nor linear, it is common to predistort the signal to obtain the desired shape at the rf gap. Nevertheless, the resulting waveform still has a ripple in the flat section. This is due to the lowpass characteristic of the amplifier and the sharp edges at the ends of the sine, which lead to an infinite number of harmonics. This paper provides better suited BB-waveforms, which are designed with a finite number of harmonics from the beginning. It is shown that a much better flatness can be achieved than for a conventional BB-waveform, without sacrificing any performance. These advanced waveforms are currently used at the hadron synchrotron COSY at Forschungszentrum Jülich, leading to improved BB-bunch shapes, in particular for electron-cooled beams.
Paper: WEPA117
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPA117
About: Received: 01 May 2023 — Revised: 01 Jun 2023 — Accepted: 21 Jun 2023 — Issue date: 26 Sep 2023
WEPA125
Irradiation tests of a cavity core material and GaN devices in J-PARC Main Ring
2955
Magnetic alloy cavities have been used in many accelerators. We have irradiated small magnetic alloy rings in J-PARC to evaluate radiation effects on magnetic properties. Complex permeabilities and hysteresis curves were measured before and after the irradiation. No significant variation was observed by the total ionization dose of 18 kGy and neutron flux of 2.3$\times10^{14}$ n/cm$^2$. The doses were measured by RadMON ver.6 developed by CERN. The test will be continued to higher dose. High neutron irradiation caused radio activities and radioactive nuclei in the cores were identified in this work. We also tried to use RadMON with low gain mode. It suggested that RadMON can be used beyond 16 kGy. Gallium nitride devices were also tested for future applications in accelerator tunnels. They showed excellent radiation hardness.
Paper: WEPA125
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPA125
About: Received: 27 Apr 2023 — Revised: 08 May 2023 — Accepted: 16 Jun 2023 — Issue date: 26 Sep 2023
WEPA134
Design, fabrication and mechanical tests of TIG-welded Ka-band accelerating structures for ultra-high gradient applications
2976
The investigation of the processes, materials, technology and welding procedures used to manufacture accelerating components for maximum accelerating gradient (>100 MV/m) and minimum RF breakdown probability has led us to the proposal of hard-copper structures in Ka-Band made of multiple parts. In this paper, we illustrate the TIG welding tests, including visual inspection and temperature monitoring, of Ka-band metallic RF cavities for the cases of two-half and four-quadrant models. The RF cavities made of multiple parts operate at ultra-high accelerating gradients (well above >100 MV/m). Therefore, the following aspects of the welding procedure were used as references for the positive outcome of the process: 1) Successful execution of each weld bead/seam in order to assure vacuum tightness of the cavity. 2) The cleanliness of the inside surfaces of the cavities: visual inspection for absence of oxidation after cutting the cavity samples; 3) The temperature of the cavity surfaces always below the annealing one (mechanical properties significantly change after heating above 590 ◦C), in order to keep the hardness of the copper.
Paper: WEPA134
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPA134
About: Received: 01 May 2023 — Revised: 08 Jun 2023 — Accepted: 08 Jun 2023 — Issue date: 26 Sep 2023
WEPA148
Overview of material choices for HL-LHC collimators
2999
In view of the High-Luminosity (HL-LHC) upgrade of the LHC collimation system, different materials were investigated to determine how the jaws of the new collimators could be manufactured to meet the demanding requirements of HL-LHC, such as thermomechanical robustness and stability, RF impedance, UHV, etc. During the Long-Shutdown 2 (LS2), five primary and 10 secondary low-impedance collimators were already produced using novel material. For LS3, in addition to more secondary collimators, the production and installation of other types of collimators, including tertiaries and physics debris units, is planned. This paper details the final material choices and rationale for each collimator family.
Paper: WEPA148
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPA148
About: Received: 10 May 2023 — Revised: 11 May 2023 — Accepted: 16 Jun 2023 — Issue date: 26 Sep 2023
WEPA170
The mechanism of non-uniform distribution of tin sites on the surface of niobium during the nucleation process
3043
A uniform distribution of nucleation tin sites is essential to the growth of high quality Nb3Sn thin film by vapor diffusion method. The less-nuclear zones were commonly observed in previous nucleation experiments. However, a fully understanding of the occurrence of less-nuclear zones has not yet been achieved. Here, the adsorption energy of nuclear agent SnCl2 on different crystal planes of niobium (Nb) including Nb (110), Nb (100), Nb (211) are studied through density functional theory (DFT) calculations and several types of adsorption configurations are optimized. The large differences of calculated adsorption energy of SnCl2 on three different crystal planes reveal strong crystal direction selectivity during nucleation stage. In addition, the phenomenon of nucleation experiment on large grain samples further consolidates the accuracy of the calculation results. The calculation results explain the presence of less-nuclear zones during nucleation process and provide guidance for the subsequent suppression of these regions.
Paper: WEPA170
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPA170
About: Received: 09 May 2023 — Revised: 23 Jun 2023 — Accepted: 08 Jun 2023 — Issue date: 26 Sep 2023
WEPA175
INFN-LASA R&D on high-Q cavities for the PIP-II project
3049
As the series production of PIP-II 650 MHz low beta cavities approaches, INFN-LASA R&D activities on cavity prototypes are ongoing. Different surface treatments have been exploited in a joint effort between INFN and FNAL, to establish the series cavity recipe. Meanwhile, the vertical test facility has been upgraded for the test of high-Q cavities, by increasing its capability to reduce the trapped magnetic flux and by developing of a magnetic mapping system suitable in the cryostat environment. Here, we report the latest experimental results.
Paper: WEPA175
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPA175
About: Received: 05 May 2023 — Revised: 12 May 2023 — Accepted: 19 Jun 2023 — Issue date: 26 Sep 2023
WEPL025
Application of beam-based alignment to the CLEAR facility
3166
The CERN Linear Electron Accelerator for Research (CLEAR) has been operating since 2017 as a user facility providing beams for a large variety of experiments. Its RF photocathode-based linear accelerator can accelerate electrons up to 220 MeV with a bunch charge of 0.1-1.5nC with single or up to 150 bunches per train. The flexibility of providing various beam parameters following user demands brights drawbacks and complexity in operating the accelerator. Standard beam steering based on the sequential variation of quadrupole and corrector magnets, performed by an operator manually, results in a very time-consuming process. This paper presents a tool we developed for automatic and global Beam-Based Alignment (BBA) for CLEAR based on dispersion-free steering and one-to-one corrections to transport beams with various charges and time structures.
Paper: WEPL025
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPL025
About: Received: 04 May 2023 — Revised: 14 Jun 2023 — Accepted: 14 Jun 2023 — Issue date: 26 Sep 2023
WEPL054
CEBAF Injector Model for K-Long bunch charge at 200 kV
3236
The upcoming Jefferson Lab K-Long experiment at Hall D will require unique beam conditions with a much lower bunch repetition rate and atypically high bunch charge. To optimize the Continuous Electron Beam Accelerator Facility (CEBAF) injector for this experiment, we performed Multi-Objective Genetic Optimization (MGO) using General Particle Tracer (GPT) to determine the magnetic elements and RF settings necessary for the K-long bunch charge (0.64 pC) at 200 kV. We also investigated the transmission and beam characteristics of low to high charge per bunch electron beams through the injector for simultaneous operations of all four CEBAF Halls and characterized the transmission as a function of the photocathode laser spot size and pulse length. Our findings provide valuable insights into optimizing the CEBAF injector for the Jefferson Lab K-Long experiment, as well as for other experiments with similar beam conditions.
Paper: WEPL054
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPL054
About: Received: 02 May 2023 — Revised: 04 May 2023 — Accepted: 15 Jun 2023 — Issue date: 26 Sep 2023
WEPL060
An improved method for linear optics and coupling correction based on closed orbit modulation
3252
A new method is introduced to process the closed orbit modulation by two corrector magnets modulated with sinusoidal waveforms. The new method can extract linear optics information from tens of thousands of orbits and represent such information with only a few parameters per beam position monitor. The concise form makes it easy to fit for linear lattice errors. The method has been demonstrated for linear optics correction on SPEAR3 and NSLS-II storage rings. One iteration of optics correction, including data taking and lattice fitting, takes only tens of seconds.
Paper: WEPL060
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPL060
About: Received: 02 May 2023 — Revised: 11 May 2023 — Accepted: 23 Jun 2023 — Issue date: 26 Sep 2023
WEPL074
High accuracy optics measurement in J-PARC MR for 1.3 MW upgrade plan
3276
J-PARC MR is a high intensity synchrotron that accelerates protons from 3 GeV to 30 GeV. In MR, beam study for 1.3 MW upgrade plan is now in progress. The upgrade is done by shortening the repetition period and increasing the number of protons, and it is crucial to understand their effects on beam motion. Especially, the betatron function is one of the most important parameters that determines the beam motion. In MR, the betatron function has been measured by using turn-by-turn signal of the beam position monitor. Betatron function has been adjusted to match with model within 3% accuracy in relative error in low energy period. However, in evaluating the effects of space charge forces and eddy currents on beam optics whose impact will be largen by the upgrade, the accuracy of betatron function measurement during the injection and acceleration period will be even more important. In this study, we have attempt to match betatron function to model within 1% accuracy in relative error both in injection and acceleration period which has never been achieved in MR, by performing beta function measurement using COD response from the steering magnets in MR.
Paper: WEPL074
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPL074
About: Received: 03 May 2023 — Revised: 24 May 2023 — Accepted: 24 May 2023 — Issue date: 26 Sep 2023
WEPM058
Energy deposition simulations for a damage experiment with superconducting sample coils
3696
An experiment to study damage caused by the impact of 440 GeV/c protons on sample superconducting racetrack coils made from NbTi and Nb3Sn strands was recently carried out at CERN's HiRadMat facility. This paper reports on the detailed Monte Carlo simulations performed with FLUKA and Geant4 to evaluate the energy deposition of the 440 GeV/c proton beam on the sample coils positioned in the experimental setup. using the measured beam parameters during the experiment. The measured hotspot temperatures and temperature gradients reached in the sample coils are presented and compared with the simulations. In addition, comparisons between the simulation results from FLUKA and Geant4 are discussed in detail.
Paper: WEPM058
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPM058
About: Received: 03 May 2023 — Revised: 23 May 2023 — Accepted: 23 May 2023 — Issue date: 26 Sep 2023
WEPM059
Damage experiment with superconducting sample coils - experimental setup and observations during beam impact
3700
The damage mechanisms and limits of superconducting accelerator magnets caused by the impact of high-intensity particle beams have been the subject of extensive studies at CERN in the recent years. Recently, an experiment with dedicated racetrack coils made of Nb-Ti and Nb3Sn strands was performed in CERN’s HiRadMat facility. In this paper, the design and construction of the sample coils as well as the results of their qualification before the beam impact are described. Furthermore, the experimental setup is discussed. Finally, the measurements during the beam experiment such as the beam-based alignment, the observations during the impact of 440 GeV protons on the sample coils and the obtained hotspots and temperature gradients are presented.
Paper: WEPM059
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPM059
About: Received: 03 May 2023 — Revised: 11 May 2023 — Accepted: 16 Jun 2023 — Issue date: 26 Sep 2023
WEPM070
Investigations on NbTi superconducting racetrack coils under pulsed-current excitations
3735
One of the key issues in the technology of superconductors is the protection against quenches. When designing a superconductor as a magnet, a coil or even current leads, the design should be made such that the superconductor withstands all operational conditions as fast discharges, pulsed loads or even rapid transient background fields. Computational modeling of pulsed-current characterization in a self-field NbTi racetrack sample coil has been performed using the finite element modelling software Opera as a step towards understanding the thermal and electromagnetic processes during a quench. The pulse was modelled to be generated by discharging a capacitor into an RLC circuit, which includes the NbTi racetrack coil as the sample under test. The coil was driven to the resistive state and the quench occurred by applying the pulse with a peak value exceeding the critical current of the sample coil. This contribution presents the results obtained from investigating a pulsed NbTi coil in a model based on an electromagnetic analysis. In addition, a comparison to the theoretical expectations derived for the damped oscillations in the pulse-driving circuit is given. Finally, the results from a coupled analysis, where both thermal and electromagnetic properties are being considered, within a quench multi-physics study are presented.
Paper: WEPM070
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPM070
About: Received: 01 Apr 2023 — Revised: 16 May 2023 — Accepted: 19 Jun 2023 — Issue date: 26 Sep 2023
WEPM109
Beam-Impact Validation of HL-LHC Collimator Materials: the "MultiMat-2" Experiment
3822
In 2017, a proton-impact test HL-LHC collimator materials was carried out in the HiRadMat facility at CERN. The experiment, called “MultiMat”, enabled the testing of bulk and coated materials developed at CERN for different beam collimation functionalities. Manufacturing of these materials was then passed to the industry, leading to a series production for use in the collimators installed in the LHC during Long Shutdown 2 (LS2). The industrial versions of bulk and coating materials were tested in HiRadMat in 2021 in the “MultiMat-2” experiment, that efficiently re-used of the same experimental test bench as for “MultiMat”. This new experiment proved the reliability of the absorbers installed in LS2, and confirmed the possible use of alternative materials and coatings for the next LS3 collimator production. This paper describes the preparation and beam parameters of “MultiMat-2”, the experimental and data-acquisition equipment and the main results of the experiment.
Paper: WEPM109
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPM109
About: Received: 11 May 2023 — Revised: 16 Jun 2023 — Accepted: 16 Jun 2023 — Issue date: 26 Sep 2023
WEPM112
Target systems design for a high intensity facility in the CERN's ECN3 area
3830
A new high intensity fixed target facility could be accommodated at CERN by fully exploiting the Super Proton Synchrotron. Multiple physics experiment proposals such as BDF/SHiP, NA62-BD, HIKE and SHADOWS are being considered. Amongst the different possibilities to locate such experiments and their respective target complex at CERN, the ECN3 hall in the North Area has been selected for further study. This contribution will detail the status of the design and physics optimisation of the target systems proposed for a high intensity upgrade in the CERN's North Area ECN3. Radiation protection considerations, remote handling strategy, services supply, installation, operation, maintenance, and decommissioning aspects are herein discussed.
Paper: WEPM112
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPM112
About: Received: 30 Apr 2023 — Revised: 11 May 2023 — Accepted: 19 Jun 2023 — Issue date: 26 Sep 2023
WEPM121
Logistics strategies for Elettra 2.0
3845
Logistics is not "rocket science" nevertheless a poor coordination and planning of procurement, transportation, and storage can cause congestion in the supply and movimentation of components and systems, increasing the risk of delays, damages and - worst of all - injuries to the personnel. Upgrading an existing machine doubles the difficulties, handling the old parts and the new ones, almost at the same time. This paper deals with the activities carried on so far for Elettra 2.0 Project, with main focus on the removal and handling of the existing Storage Ring (SR) and the associated systems. Different approaches have to be adopted for what is contained in the SR tunnel – subject to radio protection verification – and what is external to the tunnel and can be more easily handled. Additionally, parts to re-use and those that must be temporary removed, protected and stored require different procedures from the other ones to discard and dispose.
Paper: WEPM121
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPM121
About: Received: 02 May 2023 — Revised: 06 May 2023 — Accepted: 15 Jun 2023 — Issue date: 26 Sep 2023
WEPM127
The CMS Enfourneur n.2: a Huge, Lean, and Safe Machine for LS3 ECAL Upgrade
3866
In preparation for the High Luminosity phase of the LHC at CERN, to start in 2029, a refurbishment of the electronics of the CMS electromagnetic calorimeter (ECAL) is planned. The ECAL barrel section is organized in 36 elements called Supermodules (SMs), 18 in each side. All SMs, weighing about 3 tons each, must be ex-tracted, upgraded and inserted again during the Long Shutdown 3 (LS3) using two large machines, Enfourneur n.1 (E1) and n.2 (E2) operating one per each CMS side. E1 – used for the original SMs installation - has been heavily upgraded to be compliant with the current safety norms, but the demands from the logistics of the CMS cavern and the tight schedule require to produce a second machine. The new E2 machine must meet some major engineering challenges: maintaining or improving func-tionality and safety in compliance with European regula-tions in terms of safety (Eurocodes and the Machinery Directive in particular), as well as being installable in the CMS plus side, which is only accessible through narrow shafts and tunnels. E2 was therefore designed in a modu-lar way, harmonizing functional and structural require-ments with the space and tools available for transport and installation. Functionality and safety have also been improved by replacing hydraulic actuation with electri-cally driven controls and motors, resulting in refined positioning capabilities and simplified procedures for handling heavy, voluminous, and extremely delicate objects such as supermodules. The E2 design is currently complete and the construction has started in January 2023.
Paper: WEPM127
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-WEPM127
About: Received: 03 May 2023 — Revised: 10 May 2023 — Accepted: 20 Jun 2023 — Issue date: 26 Sep 2023
THODB3
Sustainability in storage ring based light sources
3936
Climate change and its consequences require strong changes in our consumption modes and approaches. Large research infrastructures consume a large amount of various energy sources, from helium to electricity. Therefore, their societal impact in the current energy crisis is tremendous, as well as their environmental impact. The Energy for Sustainable Science at Research Institutes workshop, held every two years, gathers a large panel of institutes whose efforts and ideas aim towards a less energy consuming and impactful science.
Paper: THODB3
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THODB3
About: Received: 03 May 2023 — Revised: 08 Jun 2023 — Accepted: 08 Jun 2023 — Issue date: 26 Sep 2023
THPA011
Study of noise impact on AI-based ptychography for beam characterization
3970
Coherent X-ray beam focus can be characterized using ptychography, a lensless imaging technique used at synchrotron X-ray light sources and free-electron lasers. Ptychography relies on collecting X-ray diffraction from a thin sample at overlapping regions and reconstructing an image from the data. Since the phase is not measured by the detector, ptychography can solve for the phase of the sample and the probe. This is useful for characterizing the beam focus, coherence, and energy dependence, and for exploring experimental conditions. Ptychography, however, is challenging due to the time to collect data from each sample point and also for iterative reconstruction of the phase. Recently, AI-based ptychographic methods have shown promise in making ptychography-based beam characterization faster and more efficient. This poster presents a study on the effect of various types of noise present in ptychographic data. A number of noise sources occur in ptychographic setups and include noise from parasitic scattering (background), outliers, correlated noise sources, cosmic rays, bad frames, beam jitter, motor jitter, fluctuating dark noise, beam miscentering, a static sloped background and fluence jitter. This study explores the effect of random noise in experimental data used for AI-based ptychographic reconstruction and how it impacts reconstructed probe and object image accuracy. Results on noise impact using both AI-based and iterative ptychographic methods are compared.
Paper: THPA011
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPA011
About: Received: 30 Apr 2023 — Revised: 08 May 2023 — Accepted: 23 Jun 2023 — Issue date: 26 Sep 2023
THPA049
The Personnel Access System for FAIR
4067
Once completed, the Facility for Antiproton and Ion Research in Europe GmbH, FAIR, is to be one of the leading nuclear physics laboratories in Europe and one of the largest and most versatile accelerator complexes worldwide. FAIR can serve a number of experiments simultaneously, using fast-cycling synchrotrons. In this context, safety of personnel has the highest priority. The essential function of the Personnel Access System (PAS) is to prevent the presence of personnel in areas with particle beam or its secondary radiation. A particular challenge for FAIR is the large number of areas where personnel can access. For efficiency, it is required that during access to some areas, the beam operation continues in other areas of FAIR. For other hazards (e.g. electrical hazards, RF, laser beams) in certain areas, the PAS ensures that only personnel with adequate authorization can access and provides a safety signal to switch off hazardous equipment. Based on safety PLCs for the control system, the PAS uses some novel technologies such as hand vein scanners and safety radar systems.
Paper: THPA049
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPA049
About: Received: 02 May 2023 — Revised: 11 May 2023 — Accepted: 12 May 2023 — Issue date: 26 Sep 2023
THPA057
Reliability studies for CERN’s new safe machine parameter system
4085
The Safe Machine Parameter system (SMP) is a critical part of the machine protection system in CERN’s Large Hadron Collider (LHC) and the Super Proton Synchrotron (SPS). It broadcasts safety-critical parameters like beam energy, beam intensity, the beta functions and flags indicating safety levels of the beam to other machine protection elements. The current SMP will be replaced by a consolidated system during CERN’s Long Shutdown 3, foreseen to start in 2026. In this contribution the results of the reliability study of the new SMP system are presented. This study quantifies the criticality of end-users by identifying the hazard chains leading to potential damage of the involved equipment. Data-driven risk matrices are used to derive acceptable failure frequencies and reliability requirements. The study encompasses Monte Carlo simulations of sub-system level configurations to support the decision-making process in this project.
Paper: THPA057
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPA057
About: Received: 03 May 2023 — Revised: 10 May 2023 — Accepted: 19 Jun 2023 — Issue date: 26 Sep 2023
THPA073
Developing a two-colour all-fibre balanced optical cross-correlator for sub-femtosecond synchronisation
4135
In modern accelerator facilities, femtosecond synchronisation between an optical master oscillator (OMO) that provides facility-wide timing pulses and an external experiment laser is needed to achieve the few-fs resolution required for experiments such as pump-probe spectroscopy. This can be achieved with a balanced optical cross-correlator (BOXC), which determines the timing delay between two laser pulses via the generation of sum-frequency radiation in a nonlinear crystal. In this paper, a design for a two-colour fibre-coupled BOXC using waveguided periodically-poled lithium niobate (PPLN) crystals is presented. An all-fibre two-colour BOXC is highly desirable as it would be more robust against environment fluctuations, easier to implement, and can achieve greater synchronisation performance compared to free-space coupled BOXCs that are currently used in accelerator facilities. This proposed design can theoretically achieve 5 - 10 times greater sensitivity to relative timing changes between laser pulses than current free-space two-colour BOXCs, which can make sub-fs synchronisation between an OMO and an external experiment laser of different wavelength achievable.
Paper: THPA073
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPA073
About: Received: 28 Apr 2023 — Revised: 09 May 2023 — Accepted: 11 May 2023 — Issue date: 26 Sep 2023
THPA075
Synchronization and phase locking of resonant magnet power supplies for Mu2e experiment at Fermilab
4139
The Mu2e Experiment has stringent beam structure requirements; namely, it requires short (~200 ns) proton bunches separated by 1.5-2.0 $\mu$s. This beam structure will be produced using the Fermilab 8 GeV Booster, the 8 GeV Recycler Ring, and the Delivery Ring, which was formerly part of the antiproton accumulator system. Out of time beam is limited to a fraction of level of no more than $1\times 10^{-10}$, a requirement known as "extinction". Achieving this level of extinction requires a system of resonant magnets and collimators, phased such that only in time particles will pass through. The Mu2e magnet system involves two components: a 300 kHz component, timed such that the 600 kHz beam will pass through the collimators at the nodes, and a 4.5 MHz system to reduce the slewing of the in-time beam. These two systems must be precisely phase locked to the bunch rate coming from the Delivery Ring, which itself must be phased to match beam transfers coming from the Recycler. This poster describes the control system for the magnets, which is based on an Intel Arria FPGA, which handles phase locking of the magnets to the Delivery Ring, including the phase jumps required to match transfers from the Recycler.
Paper: THPA075
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPA075
About: Received: 04 May 2023 — Revised: 11 May 2023 — Accepted: 16 Jun 2023 — Issue date: 26 Sep 2023
THPA079
Characterization and optimization of laser-generated THz beam for THz based streaking
4149
At the Ferninfrarot Linac- und Test-Experiment (FLUTE) at the Karlsruhe Institute of Technology (KIT) a new and compact method for longitudinal diagnostics of ultrashort electron bunches is being developed. For this technique, which is based on THz streaking, strong electromagnetic pulses with frequencies around 240 GHz are required. Therefore, a setup for laser-generated THz radiation using tilted-pulse-front pumping in lithium niobate was designed, delivering up to 1 µJ of THz pulse energy with a conversion efficiency of up to 0.03 %. In this contribution we study the optimization of the THz beam transport and environment.
Paper: THPA079
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPA079
About: Received: 02 May 2023 — Revised: 05 Jun 2023 — Accepted: 22 Jun 2023 — Issue date: 26 Sep 2023
THPA123
Development of a new online model application for the high-energy beam transfer lines at GSI
4251
The high-energy beam transfer lines at GSI serve numerous experimental stations such as HADES, HTC and HTD as well as the fragment separator FRS and the storage rings ESR and CRYRING with a wide range of different heavy ion beams from the SIS18 synchrotron. The large amount of experiments carried out during beam times under different beam conditions require frequent changes of beam optics and beam steering in the transfer lines. In the past, the online model tool "Mirko Expert" was available for this purpose, which however is not compatible with the new control system infrastructure. Therefore, a new online model application based on the MAD-X beam dynamics simulation code and the JMad programming interface is under development in Java. This paper presents the concept and features of the new online model application, as well as possible future extensions. Efforts to overcome discrepancies in the present Mirko and MAD-X optics models are also discussed.
Paper: THPA123
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPA123
About: Received: 28 Apr 2023 — Revised: 08 May 2023 — Accepted: 15 Jun 2023 — Issue date: 26 Sep 2023
THPA128
An online analysis platform for improving X-ray light source operations
4266
The design, execution, and analysis of light source experiments requires the use of sophisticated simulation, controls and data management tools. Existing workflows require significant specialization to accommodate specific beamline operations and data pre-processing steps necessary for more intensive analysis. Recent efforts to address these needs at the National Synchrotron Light Source II (NSLS-II) have resulted in the creation of the Bluesky data collection framework, an open-source library for coordinating experimental control and data collection. Bluesky provides high level abstraction of experimental procedures, instrument readouts, and data analyses to encapsulate data collection workflows. We present a prototype data analysis platform for integrating data collection with real time analysis at the beamline. Our application leverages Bluesky to provide data selection, in combination with a flexible run engine to execute user configurable Python-based analyses with customizable queueing and resource management. We discuss initial demonstrations to support X-ray photon correlation spectroscopy experiments and future efforts to expand the platform's features.
Paper: THPA128
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPA128
About: Received: 03 May 2023 — Revised: 10 May 2023 — Accepted: 11 May 2023 — Issue date: 26 Sep 2023
THPA140
Vacuum design of the Super-FRS at FAIR
4287
The large-acceptance Superconducting Fragment Separator (Super-FRS) at the Facility for Antiproton and Ion Research (FAIR) at GSI Darmstadt poses peculiar challenges for its vacuum systems. Although the vacuum levels ranging from 1E-5 to 1E-7 mbar for the single-pass beamline are rather undemanding in absolute values, a combination of high level of prompt and residual radiation in the target and pre-separator area, highly outgassing and self-sealing inserts, and large volumes not usually encountered in accelerator systems are setting exceptional demands on the design of the vacuum systems. The radiation environment also has an impact on regular maintenance and emergency intervention strategies as well as on radiation hardness requirements of the standard vacuum components. We present the vacuum layout of the Super-FRS, giving an overview of the major vacuum requirements with pressure profiles from analytical as well as Molflow+ simulations of selected vacuum sectors. Additionally, the solutions implemented for remote handling of the standard and special vacuum components are discussed.
Paper: THPA140
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPA140
About: Received: 08 May 2023 — Revised: 06 Jun 2023 — Accepted: 06 Jun 2023 — Issue date: 26 Sep 2023
THPA146
Study of titanium coating of multipole injection kicker by magnetron sputtering method
4298
One of the projects for upgrading at the Taiwan Photon Source (TPS) is the design and fabrication of an improved multipole injection kicker (MIK). The aim is to improve the injection efficiency using four kickers, to deliver transparent injections during the top-up operation. A uniform titanium coating on the inner surface of the ce-ramic substrate is required to reduce the impedance of the stored electron beam and to conduct the image current. The study results of the deposition of a titanium film on a ceramic substrate (30 cm × 6 cm ) in a long vacuum chamber show that the thickness uniformity of the thin film can be controlled within 5 % with an electrical resis-tivity of 2 × 10-4 ohm-cm. The adhesion between the ceramic substrate and the titanium film meet the highest ASTM-D3359 5B requirements (bonding strength 39.2 MPa). The details of the coating set-up, experimental processes and measurement method are described in this paper.
Paper: THPA146
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPA146
About: Received: 02 May 2023 — Revised: 10 May 2023 — Accepted: 11 May 2023 — Issue date: 26 Sep 2023
THPA154
The effect of small bends in thin non-evaporable getter coated tubes on the partial pressure ratio as a function of sticking probability
4320
Non-evaporable getter (NEG) coated vacuum cham-bers are widely used as a vacuum solution in modern particle accelerators. In the development and testing of new NEG coatings to produce better vacuum, the pumping properties are evaluated. In this paper, Test Particle Monte-Carlo Simulations are created to investigate whether small bends in sample tubes may affect the results of pumping speed measurements, and therefore lead to a set of inaccurate results. With the preference to move towards smaller beam emittance in new accelerators, the required aperture of the beam vacuum chamber is getting smaller as well. The chambers are thus becoming more delicate (less mechanically stable), and able to be bent, therefore creating the risk that when NEG-coated samples are created, a bend in the tube is skewing the results. Findings have shown that a bend of less than 1° could lead to a change in results by a factor of 10 in a sticking probability, which is a severe difference that cannot be ignored. The results have a strong correlation with the molecular beaming area from the bottom to the top of the modelled tubes. In future, it will be important to define how straight a tube must be to obtain accurate pumping property measurements.
Paper: THPA154
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPA154
About: Received: 03 May 2023 — Revised: 07 May 2023 — Accepted: 11 May 2023 — Issue date: 26 Sep 2023
THPA187
A new product lifecycle management platform for CERN’s accelerator complex and beyond
4403
Particle accelerator projects are complex, and CERN’s current engineering tools already manage millions of documents that follow various lifecycles and workflows. Future projects will push size and complexity to yet higher levels, in addition to increased collaboration with external partners. As reliable data is critical for success of complex system design, CERN is now implementing a new PLM (Product Lifecycle Management) platform that outperforms previous disparate design data management systems in several aspects: Consolidation of legacy data in a consistent data model; Federation of data from different systems and external partners in a common structure; Processes with flexible Workflows and Lifecycles; Integration with Simulation, Manufacturing, Maintenance, and other services dealing with design and product data. The overarching goal for the new PLM platform is to act as a catalyser for improved quality and traceability of data (often known as the “Digital Thread”) and to serve as the foundation for Digital Twins of current and future accelerators with the aim to drastically reduce development times as well as operation and maintenance cost.
Paper: THPA187
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPA187
About: Received: 03 May 2023 — Revised: 11 May 2023 — Accepted: 19 Jun 2023 — Issue date: 26 Sep 2023
THPA189
Development of a combined element with an electric and magnetic fields for the JEDI experiment
4406
Precision measurements of the permanent electric dipole moment (EDM) of fundamental particles require the development of new methods and techniques. The precursor experiments to measure the proton and deuteron EDM at the Cooler Synchrotron COSY in Jülich led to the of a ring concept with combined magnetic and electric field elements. The building of high-stability electric and magnetic field deflectors is one of the technical challenges of this project. The previous studies on small-size deflectors have shown promising results in achieving high electric field strengths. For the present tests, a large-gap dipole magnet with a suitable vacuum chamber is equipped with a real-size prototype 1 m long deflector plates. Using high-voltage (200 kV) precision power converters we are aiming to achieve the design values of the prototype electrostatic ring of the order of 7 MV/m with 60 mm spacing between the electrodes in a presence of a necessary magnetic field. The setup for studying the electric and magnetic field strength at various distances, as well as the results of the measurements, will be presented.
Paper: THPA189
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPA189
About: Received: 03 May 2023 — Revised: 22 May 2023 — Accepted: 22 Jun 2023 — Issue date: 26 Sep 2023
THPL002
Development and commissioning of a new materials irradiation station at ATLAS
4416
A new dedicated materials irradiation beamline and target station was developed and recently commissioned at the ATLAS facility at Argonne National Laboratory. The new ATLAS Materials Irradiation Station (AMIS) is located just downstream of the first linac section (PII) and designed to receive heavy-ion beams with energies of 0.5 - 1.5 MeV/u. The main activity at AMIS is the irradiation of samples for radiation damage studies of nuclear materials. The facility will provide a unique accessible platform for accelerated testing of nuclear fuels and materials that support the testing and deployment of new materials for advanced reactors in a short period of time, which otherwise can take years of testing in conventional reactors. Although the focus of the AMIS line is to irradiate and investigate materials for nuclear energy applications, other research and applications are welcome. In particular, more beam time will be available following the completion of the ongoing ATLAS multi-user upgrade which will allow simultaneous beam sharing between different experimental stations. The development and commissioning results of the AMIS beamline will be presented and discussed.
Paper: THPL002
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPL002
About: Received: 04 May 2023 — Revised: 08 Jun 2023 — Accepted: 08 Jun 2023 — Issue date: 26 Sep 2023
THPL038
Ultra fast reinforcement learning demonstrated at CERN AWAKE
4510
Reinforcement learning (RL) is a promising direction in machine learning for the control and optimisation of particle accelerators since it learns directly from experience without needing a model a-priori. However, RL generally suffers from low sample efficiency and thus training from scracth on the machine is often not an option. RL agents are usually trained or pre-tuned on simulators and then transferred to the real environment. In this work we propose a model-based RL approach based on Gaussian processes (GPs) to overcome the sample efficiency limitation. Our RL agent was able to learn to control the trajectory at the CERN AWAKE (Advanced Wakefield Experiment) facility, a problem of 10 degrees of freedom, within a few interactions only. To date, numerical optimises are used to restore or increase and stabilise the performance of accelerators. A major drawback is that they must explore the optimisation space each time they are applied. Our RL approach learns as quickly as numerical optimisers for one optimisation run, but can be used afterwards as single-shot or few-shot controllers. Furthermore, it can also handle safety and time-varying systems and can be used for the online stabilisation of accelerator operation.This approach opens a new avenue for the application of RL in accelerator control and brings it into the realm of everyday applications.
Paper: THPL038
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPL038
About: Received: 03 May 2023 — Revised: 23 Jun 2023 — Accepted: 23 Jun 2023 — Issue date: 26 Sep 2023
THPL051
Automated Faraday cup readings at ATLAS
4547
Since its commissioning, operators at the Argonne Tandem Linear Accelerator System (ATLAS) have used an analog current meter to manually record beam current measurements from Faraday cups along the beamline. Recently an automated process using a digital picoammeter was developed for beam current measurements. This automation has streamlined daily operations, increased the precision of measurements, and expedited the generation of digital data for use with ongoing artificial intelligence and machine learning work (AI/ML).
Paper: THPL051
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPL051
About: Received: 03 May 2023 — Revised: 12 Jun 2023 — Accepted: 12 Jun 2023 — Issue date: 26 Sep 2023
THPL063
Design of an electron energy spectrometer and energy selector for laser-plasma driven beams at EPAC
4568
The Extreme Photonics application Centre (EPAC) is a new national facility to support UK science, technology, innovation and industry currently under construction at the Rutherford Appleton Laboratory, UK. EPAC is designed to facilitate a wide variety of user experiments with 1PW 10Hz laser systems. It is anticipated that early experiments will include laser-plasma acceleration of electrons to energies ranging from 100 MeV up to 10 GeV, with later experiments using these electrons as a beam once stable generation is achieved. EPAC is designed to be flexible, allowing users to select the relevant central electron energy for their experiment. To achieve this goal EPAC and the Accelerator Science & Technology Centre (ASTeC) at STFC Daresbury Laboratory have been working on the design of a beamline to capture laser-plasma driven electrons with broad energy spread, measure their energy spectrum, perform selection of specific energies if necessary and deliver these electrons to a user interaction point. We present here the conceptual design of the proposed spectrometer and energy selection system.
Paper: THPL063
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPL063
About: Received: 27 Apr 2023 — Revised: 07 May 2023 — Accepted: 15 Jun 2023 — Issue date: 26 Sep 2023
THPL064
Design of a broadband modular permanent magnet electron energy spectrometer for FEBE
4572
The CLARA accelerator facility at Daresbury Laboratory, UK, was originally designed to operate as a free-electron laser test facility. To improve the user exploitation of the facility a dedicated full energy beam exploitation (FEBE) area has been designed and is currently being installed in a separate experimental bunker on the CLARA accelerator. This facility will allow users to conduct experiments combining a 250 MeV electron beam of up to 250 pC bunch charge with laser pulses up to 100 TW in a large target chamber. A second downstream chamber contains room for a number of diagnostics that are customisable to the experiments being conducted. The ability to combine a laser and electron beam in FEBE presents the possibility of novel acceleration experiments. FEBE is designed to allow user experiments which aim to further accelerate the electron beam from 250 MeV to 600 MeV, or 2 GeV at a reduced repetition rate. To measure the output of these experiments an innovative in-vacuum permanent magnet spectrometer dipole has been designed with modular construction to measure broadband electron energy spectra. The modular nature allows the length of the installed dipole to be tailored to the experiment, allowing room for additional diagnostics in experiments where maximum energies below 2 GeV are expected.
Paper: THPL064
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPL064
About: Received: 27 Apr 2023 — Revised: 07 May 2023 — Accepted: 15 Jun 2023 — Issue date: 26 Sep 2023
THPL080
Review of CERN beam instrumentation for fixed target experiments
4625
Measuring beam parameters in the vicinity of fixed target experiments or interceptive devices like beam dumps is essential to ensure efficient fixed target physics and safe beam operation. At the same time the beam diagnostic reach is very often challenging in terms of robustness and performance. This paper reviews the CERN instruments exploited to measure protons at different CERN fixed target facilities (ISOLDE, PS East Area, AD, SPS North Area, HIRADMAT) and beam dumps (SPS, LHC), focusing on recent developments/results, limitations and future plans. Emphasis will be given to beam size and beam position monitors systems and their response to high power and/or density proton beams at target locations, thus involving radiation hardness, background and power deposition issues. The discussion will also refer to new materials studies and modern machine learning techniques developed to enhance the monitors overall accuracy and reliability.
Paper: THPL080
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPL080
About: Received: 03 May 2023 — Revised: 12 May 2023 — Accepted: 22 Jun 2023 — Issue date: 26 Sep 2023
THPL098
Opendigitizer: digitizer modernisation using openCMW and GNU radio 4.0 for FAIR
4684
OpenDigitizer* is an open-source modernisation of FAIR's modular digitizer infrastructure and graphical user interface based on OpenCMW, WebAssembly, and the GNU Radio 4.0 frameworks. Already used to provide generic monitoring and first-line diagnostics for accelerator-related devices, it further supports equipment experts, operation, and FAIR users in developing basic to advanced top-level measurement and control loops. Supporting hundreds of industrial digitizers with sampling frequencies ranging from a few MS/s to GS/s, the core relies on directed signal flow graphs to express arbitrary post-processing and feedback control loop logics that are both numerically highly efficient as well as provide an intuitive high-level yet detailed nuts-and-bolts representation to inspect and/or to reconfigure existing systems by accelerator-, control- or other system domain-experts alike with little to no prior required programming experience. The diagnostics UI tools are compatible with WebAssembly (WASM) allowing their native deployment, on mobile as well as on any browser-based platform, facilitating their flexible use both in the accelerator tunnel during commissioning, trouble-shooting, as well as in the control room.
Paper: THPL098
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPL098
About: Received: 03 May 2023 — Revised: 09 May 2023 — Accepted: 20 Jun 2023 — Issue date: 26 Sep 2023
THPL100
Raspberry Pi cameras as beam induced fluorescence monitors for low and high energy beams
4692
Miniature single-board cameras have been used for several years to monitor beam-induced residual gas fluorescence. This work gives an overview of the use of so-called Raspberry Pi cameras in accelerator experiments. These devices are installed in vacuum at hard-to-reach locations. They have been tested in strong magnetic fields with low energy proton beams from 2 keV to 60 keV. They have also been tested in the high energy range with 4.8 MeV/u, $^{48}Ca^{10+}$ beams. Nitrogen and argon were used as residual gas and the pressure was varied from $1\cdot10^{-5}mbar$ to $1 mbar$.
Paper: THPL100
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPL100
About: Received: 03 May 2023 — Revised: 23 May 2023 — Accepted: 23 May 2023 — Issue date: 26 Sep 2023
THPL119
Recording two-beam LHC BPM signals to validate a technique for extracting individual beam positions
4749
As part of the High Luminosity upgrade for the Large Hadron Collider, several new directive-coupler (stripline) BPMs will be installed near the ATLAS and CMS detectors where the two counter-rotating beams exist within a single beampipe. In the worst case scenario, the bunches of the second beam arrive at the BPM location just 4 ns after those of the first and the BPM signals from the two beams overlap significantly. Using simulations of the expected BPM output, a novel scheme for digitally processing these two-beam signals in order to extract the true position of each beam has been developed. The offline validation of this technique requires genuine two-beam signals. In October 2022, suitable signals were gathered using an early proof-of-concept digital BPM processor connected to an existing room-temperature stripline BPM close to the CMS detector. During this period of data acquisition, RF cogging was used to vary the difference in arrival time of the two beam at the BPM location and orbit bumps were used to vary the beam-beam displacement in order to ultimately be able to determine the performance of the digital processing scheme.
Paper: THPL119
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPL119
About: Received: 02 May 2023 — Revised: 23 May 2023 — Accepted: 23 May 2023 — Issue date: 26 Sep 2023
THPL122
Split-ring resonator experiments and data analysis at FLUTE
4760
FLUTE (Ferninfrarot Linac- Und Test-Experiment) is a compact linac-based test facility for accelerator and diagnostics R&D located at the Karlsruher Institute of Technology (KIT). A new accelerator diagnostics tool, called the split-ring resonator (SRR), was tested at FLUTE, which aims at measuring the longitudinal bunch profile of fs-scale electron bunches. Laser-generated THz radiation is used to excite a high frequency oscillating electromagnetic field in the SRR. Electrons passing through the 20 µm x 20 µm SRR gap are time-dependently deflected in the vertical plane, leading to a vertical streaking of the electron bunch. During the commissioning of the SRR at FLUTE, large series of streaking attempts with varying machine parameters and set-ups were investigated in an automatized way. The recorded beam screen images during this experiment have been analyzed and evaluated. This contribution motivates and presents the automatized experiment and discusses the data analysis.
Paper: THPL122
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPL122
About: Received: 02 May 2023 — Revised: 09 May 2023 — Accepted: 11 May 2023 — Issue date: 26 Sep 2023
THPL174
Qualitative measurements of bunch length at CLARA using coherent transition radiation
4863
Bunch length is an important metric for user experiments at the Compact Linear Accelerator for Research and Applications (CLARA). A prototype Bunch Compression Monitor (BCM) based on Coherent Transition Ration (CTR) was recently installed and commissioned to support recent user experiments. The intensity of CTR is measured using a pyroelectric detector. A noise cancellation scheme based on a second detector offset from the focus of the CTR was used to reduce the noise caused by the broadband nature of pyroelectric detectors. Qualitative measurements of the bunch length as a function of RF phase are presented, along with an overview of the system design. Plans for an improved system are also presented.
Paper: THPL174
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPL174
About: Received: 03 May 2023 — Revised: 24 May 2023 — Accepted: 24 May 2023 — Issue date: 26 Sep 2023
THPM010
CFD studies and experimental validation of the convective heat transfer coefficient in non-fully developed flows applied to conventional geometries used in particle accelerators
4912
In the field of Particle Accelerators engineering, the design of the cooling channels of its components has been extensively based on experimental correlations for the calculation of convective heat transfer coefficients. In this scenario, this work is focused on studying whether the experimental correlations are conservative when the flow is turbulent in fully developed and non-fully developed regions. For this research, simulation models have been developed for turbulent flows in fully developed and non-fully developed regions, all of them for cooling channels with a 10 mm inner diameter. In the first case, for a circular channel, turbulence models have been studied, and comparative studies with respect to experimental correlations and previous studies performed at ALBA have been carried out. Simulation models based on the coefficients obtained from experimentally observed correlations, CFD models and an experimental validation of a mirror with inside cooling, have been performed in the second case.
Paper: THPM010
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPM010
About: Received: 27 Apr 2023 — Revised: 08 May 2023 — Accepted: 15 Jun 2023 — Issue date: 26 Sep 2023
THPM028
Anodic bonding of silicon and glass for bent monochromator
4953
Anodic bonding technology is a method which mainly by the aid of the electric field and temperature for connecting two materials such as glass-glass or glass-silicon wafer substrate by forming covalent bonding. The bent monochromator used in the synchrotron radiation which was made by high quality silicon wafer bonded onto concave cylindrical shape Pyrex glass base. In the past, it is made by gluing. The anodic bonding method for fabricating the bent monochromator which has more advantages than bonding by glue, such as tight bonging, non-intermediate, and simple process. This paper describes the detailed manufacturing processes and testing results.
Paper: THPM028
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPM028
About: Received: 07 Apr 2023 — Revised: 27 Jun 2023 — Accepted: 27 Jun 2023 — Issue date: 26 Sep 2023
THPM030
Initial high electric field – vacuum arc breakdown test results for additively manufactured pure copper electrodes
4957
Additive Machining (AM) technology is already used in many manufacturing domains and provides many benefits such as design freedom, cooling, and performance improvements as well as significant manufacturing time reduction. AM is also being considered for the manufacture of a Radio Frequency Quadrupole, where an important unknown is the voltage holding capability of AM surfaces. To address this question a series of high electrical field tests was performed on additively manufactured (AM) pure copper electrodes using the CERN pulsed dc high-voltage system. The tests were carried out with different test surface conditions such as “rough”, as built by AM, post-processed and machined. During each test, an ultra-high vacuum was maintained, and the breakdown rate monitored by changing the electric field level and pulse structure. The initial results provide the first reference values for AM built pure copper electrodes performance under vacuum arc breakdown test. According to test results, AM process and material powder characterisation as well as post-processing will be improved in preparation for RF power and beam tests on a full RFQ prototype.
Paper: THPM030
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPM030
About: Received: 03 May 2023 — Revised: 09 May 2023 — Accepted: 19 Jun 2023 — Issue date: 26 Sep 2023
THPM064
Beam properties beyond the therapeutic range at HIT
5042
The Heidelberg ion beam therapy facility HIT has more than ten years experience in patient treatment. More than 7800 patients have been treated with protons and heavy ions, about 700 are treated every year. Outside the beam time dedicated to therapy, quality assurance (QA) and machine tuning, we provide beams for a large spectrum of experiments in physics, biology and medicine which make use of various ion beam settings apart from the therapeutic application. By slow extraction the HIT synchrotron produces a wide range of spill lengths between a few ms and more than 10s. The intensity can be varied accordingly: For biological FLASH-radiation experiments we provide more than 2e9 carbon ions/s, still applying the high-quality raster-scanning beam delivery method. On the other hand, we deliver very stable low intensity beams in the order of 1000 ions/s if sensitive detector equipment is mounted. The layout of the facility was done for therapeutic ion beams with a maximum beam energy that corresponds to a penetration depth of ≈ 30cm in water and tissue accordingly. Especially for developments in ion beam radiography we now commissioned beams with higher energies for the light ions available at HIT (p, He). This paper summarizes the large variety of accelerator settings for the different experimental activities.
Paper: THPM064
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPM064
About: Received: 03 May 2023 — Revised: 21 Jun 2023 — Accepted: 21 Jun 2023 — Issue date: 26 Sep 2023
THPM073
Dual-scattering foil installation at CLEAR
5059
The CLEAR facility at CERN allows users to receive an electron beam with energy up to 200 MeV, allowing flexibility in intensity, beam size and bunch structures. Separate from the main CERN accelerator complex, it is capable of hosting numerous experiments with rapid installations at two test stands. It would be highly desirable for many applications, but particularly those of a medical nature, to be able to provide a ‘flat’ beam at CLEAR, with a uniform intensity distribution over a significant component of its transverse dimensions. Over the winter shutdown 2022-2023, a dual-scattering system has been installed in the CLEAR beamline to generate such a beam distribution. It was placed several metres upstream of the beamline end to reduce X-ray contamination in the flattened beam and increase total transmission of the beam. Studies on the flattened beam composition in terms of structure and dose were carried out, utilising a dipole directly upstream of the in-air test stand to separate the electron and X-ray components for analysis.
Paper: THPM073
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPM073
About: Received: 03 May 2023 — Revised: 11 May 2023 — Accepted: 22 Jun 2023 — Issue date: 26 Sep 2023
THPM078
VHEE and ultra high dose rate radiotherapy studies in the CLEAR user facility
5063
Given the current availability of high-gradient accelerator technology for cost effective and compact electron LINACs in the 100-200 MeV energy range, using Very High Energy Electron (VHEE) radiotherapy (RT) for cancer treatment recently gained a lot of interest. The Ultra High Dose Rate (UHDR) or FLASH dose regime, in which cancerous cells are damaged while healthy tissues are largely spared is one of the main topics studied. VHEE beams are especially adapted for FLASH RT, given their penetration depth and the high beam current, needed to treat large deep-seated tumors. In the CERN Linear Accelerator for Research (CLEAR) facility, numerous unique experiments have been initiated on VHEE and FLASH RT issues, in collaboration with several multidisciplinary user groups, including dosimetric, chemical and biological studies. The dedicated systems, techniques and methods used for VHEE/UHDR RT studies, locally developed by members of the CLEAR operation team, are presented in this paper together with a summary of the main results obtained in collaboration with the user groups.
Paper: THPM078
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPM078
About: Received: 03 May 2023 — Revised: 17 May 2023 — Accepted: 22 Jun 2023 — Issue date: 26 Sep 2023
THPM108
Generation and NRF application of Flat-Laser Compton Scattering gamma-ray beam in UVSOR
5121
Laser Compton Scattering Gamma-ray beam (F-LCS), which has a flat distribution in the energy spectrum and the special distribution, has been developed to study an isotope selective CT Imaging application in the beamline BL1U in UVSOR*. The generation of F-LCS beam has been demonstrated by using the Apple-II undulator installed in BL1U in UVSOR**. The principle of F-LCS generation, EGS5 simulation which takes into account the distribution of the laser-electron interaction region and detailed measurement results will be presented at the conference. In addition, the application of F-LCS beam to Nuclear Resonance Fluorescence (NRF) experiment has been performed in UVSOR and the result will be discussed.
Paper: THPM108
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPM108
About: Received: 02 May 2023 — Revised: 10 May 2023 — Accepted: 11 May 2023 — Issue date: 26 Sep 2023
THPM109
An objective approach to determining the steel penetration capabilities of X-ray cargo inspection systems
5124
The ANSI* steel penetration test is an important measure of the image performance capability of a cargo inspection system. Currently, the method for determining the arrow's visibility is completely subjective, as what one may deem 'visible', another may claim as not. An objective method is to calculate the contrast-to-noise ratio (CNR) between the steel plate and the arrow. A series of penetration scans were taken with the thickness of the steel plate ranging from 290-335 mm, and it was found that CNR decreases with increasing steel thickness. There is a point at which the CNR begins to level off - namely the 'limit of determination'. This is where the arrow can be objectively deemed as being no longer visible and, in this experiment, it was found to be at a CNR of around 0.23-0.25. Under-sampling the image data was also tested, and it was found that it did not have a detrimental effect on the CNR, and therefore the image performance. Once tested on more data sets, a definite value of the 'limit of determination' can be found. In future, this method has the capability of replacing the current method as an objective approach to determining the visibility of the arrow, and therefore measuring image performance using the steel penetration test.
Paper: THPM109
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPM109
About: Received: 24 Apr 2023 — Revised: 06 Jun 2023 — Accepted: 06 Jun 2023 — Issue date: 26 Sep 2023
THPM116
Respiratory protective equipment fit tests for researchers at the National Synchrotron Radiation Research Center
5134
Researchers at the National Synchrotron Radiation Re-search Center should use respiratory protective equip-ment to prevent respiratory damage caused by gases, steam, solvents, chemicals, materials containing toxic substances, and oxygen-deficient environments. Those working with organic matter and certain chemical sub-stances and those exposed to occupation dust should use respiratory protective gear to ensure their health. This study conducted qualitative and quantitative fit tests for various mask brands and sizes, namely 3M-9042, N95-9211, P95-8576, and 3M-6200 masks. The gear worn by all 18 participants in the qualitative fit test passed. By contrast, the gear worn by 12 of the 15 participants in the quantitative test passed; the failure of the remaining gear was due to differences in face shape. The N95-9211 mask can be used in three-piece protective gear because it exhibited a tight fit. Additionally, the 3M-6200 negative-pressure half-face mask exhibited the most satisfactory fit and can be used in protective gear.
Paper: THPM116
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPM116
About: Received: 10 May 2023 — Revised: 15 Jun 2023 — Accepted: 15 Jun 2023 — Issue date: 26 Sep 2023
THPM117
Interactive automated Bragg peak identification with 3D neutron scattering data
5138
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, neutron wavelength, and environmental conditions. RadiaSoft and Oak Ridge National Laboratory personnel are considering single-crystal diffraction data from the TOPAZ instrument. We are leveraging a new method for rapid, interactive analysis of neutron data using NVIDIA’s IndeX 3D volumetric visualization framework. 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. The implementation of automatic peak identification into IndeX allows scientists to visualize and analyze data in real-time. Our methods include a robust comparison with current analysis techniques which show improvement in a variety of aspects. These improvements will be incorporated into IndeX for visualization to allow scientists an interactive tool for crystal analysis.
Paper: THPM117
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPM117
About: Received: 03 May 2023 — Revised: 19 May 2023 — Accepted: 19 May 2023 — Issue date: 26 Sep 2023
THPM121
Construction of and experiments with a compact plasma source
5146
Experiments requiring the use of plasma sources often have trouble getting time on large plasma sources to perform their experiments despite needing only a few centimeters of high density plasma. It is significantly more convenient to have a short, high density plasma source that is available on demand for immediate experimentation. A capillary discharge plasma source was built at UCLA for this exact reason and is due to enter experimental service soon. Using argon gas and a spontaneous breakdown approach to plasma formation, this capillary is capable of generating plasmas up to 10^14 cm^-3 with a repetition rate of about 10 seconds without requiring excessive laboratory space. This compact plasma source will be used in experiments involving the SAMURAI and AWA facilities, whose results will be evaluated against the MHD code FLASH. This paper will discuss the theory behind and construction of a capillary discharge plasma source and interferometric diagnostic system, and present experimental results that utilized this plasma source.
Paper: THPM121
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPM121
About: Received: 03 May 2023 — Revised: 29 Aug 2023 — Accepted: 23 Jun 2023 — Issue date: 26 Sep 2023
THPM129
Upgrade plans and new target stations for the HZB cyclotron
5169
The HZB cyclotron provides protons for eye-tumor treatment in collaboration with the Charité – Universitätsmedizin Berlin. So far, more than 4300 patients have been treated. Parallel to therapy, there is an on-going R & D program for beam dosimetry and beam delivery. Furthermore, beam time is used for external users, e.g. the irradiation of geological samples or radiation hardness tests. For the irradiation of geological samples, a new experimental setup was designed and implemented. For radiation hardness tests, the set-up has been equipped with a new camera for measuring the spatial beam distribution. The use of this camera facilitates the area determination of irregularly formed beam shapes. For the measurements of degradation of solar cells their response is monitored on-line in parallel with the incoming proton beam. In response of requests of our users, a new target station for the irradiation of solar cells is planned. This target station will be equipped with in-situ luminescence measurements. Furthermore, a study for a cyclotron being able to deliver He and protons with an energy of 70 MeV/u has been started.
Paper: THPM129
DOI: reference for this paper: 10.18429/JACoW-IPAC2023-THPM129
About: Received: 28 Apr 2023 — Revised: 11 May 2023 — Accepted: 19 Jun 2023 — Issue date: 26 Sep 2023