Keyword: experiment
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MOPLXGD3 The Accelerator and Beam Physics of the Muon g-2 Experiment at Fermilab storage-ring, positron, lattice, betatron 10
 
  • D.A. Tarazona
    Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
 
  The physics case of the Muon g-2 Experiment at Fermilab is outstanding and has recently attracted significant attention from its first official results. Although its measurements involve high energy physics methods, such as counting positron production rates with the use of calorimeters and beam diagnostics with tracking detectors, this experiment is strongly bound to accelerator and beam physics. This paper reviews the principles of the experiment and the details necessary to provide a solid ground for the beam-dynamics uncertainties and the corrections of the systematic effects influencing the output of the experiment: a single numerical value, which may unveil new physics.  
slides icon Slides MOPLXGD3 [29.311 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPLXGD3  
About • Received ※ 08 June 2022 — Revised ※ 09 June 2022 — Accepted ※ 13 June 2022 — Issue date ※ 09 July 2022
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MOOYGD2 The AWAKE Experiment in 2021: Performance and Preliminary Results on Electron-Seeding of Self-Modulation proton, electron, plasma, wakefield 21
 
  • E. Gschwendtner, L. Verra, G. Zevi Della Porta
    CERN, Meyrin, Switzerland
  • P. Muggli, L. Verra
    MPI, Muenchen, Germany
  • P. Muggli
    MPI-P, München, Germany
  • L. Verra
    TUM, Munich, Germany
 
  The future programme of the Advanced Wakefield (AWAKE) experiment at CERN relies on the seeded self-modulation of an entire proton bunch, resulting in phase-reproducible micro-bunches. This important milestone was achieved during the 2021 proton run by injecting a short electron bunch ahead of the proton bunch, demonstrating for the first time the electron-seeding of proton bunch self-modulation. This talk describes the programme, performance and preliminary results of the AWAKE experiment in the 2021 proton run, and introduces the program of the 2022 proton run. The observation of electron-seeded self-modulation opens new avenues of exploration which will be studied in 2022, including the effect of a phase difference between the front and the back of a proton bunch and the possibility of reproducibly seeding the hosing instability using the electron beam.  
slides icon Slides MOOYGD2 [7.040 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOOYGD2  
About • Received ※ 07 June 2022 — Revised ※ 16 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 16 June 2022
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MOPOST021 ReAccelerator Upgrade, Commissioning and First Experiments at the National Superconducting Cyclotron Laboratory (NSCL) / Facility for Rare Isotope Beams (FRIB) cryomodule, MMI, linac, ion-source 101
 
  • A.C.C. Villari, G. Bollen, K.D. Davidson, K. Fukushima, A.I. Henriques, K. Holland, S.H. Kim, A. Lapierre, T. Maruta, D.G. Morris, S. Nash, P.N. Ostroumov, A.S. Plastun, J. Priller, B.M. Sherrill, R. Walker, T. Zhang, Q. Zhao
    FRIB, East Lansing, Michigan, USA
  • B. Arend, D.B. Crisp, D.J. Morrissey, M. Steiner
    NSCL, East Lansing, Michigan, USA
 
  Funding: Work supported by the NSF under grant PHY15-65546 and DOE-SC under award number DE-SC0000661
The reaccelerator ReA is a state-of-the-art super-conducting linac for reaccelerating rare isotope beams produced via inflight fragmentation or fission and subse-quent beam stopping. ReA was subject of an upgrade that increased its final beam energy from 3 MeV/u to 6 MeV/u for ions with charge over mass equal to 1/4. The upgrade included a new room-temperature rebuncher after the first section of acceleration, a new β = 0.085 QWR cryomodule and two new beamlines in a new ex-perimental vault. During commissioning, beams were accelerated with near 100 percent transport efficiency through the linac and delivered through beam transport lines. Measured beam characteristics match those calcu-lated. Following commissioning, stable and long living rare isotope beams from a Batch Mode Ion Source (BMIS) were accelerated and delivered to experiments. This con-tribution will briefly describe the upgrade, and results from beam commissioning and beam delivery for experi-ments.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOST021  
About • Received ※ 07 June 2022 — Revised ※ 12 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 21 June 2022
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MOPOST024 A Local Modification of HL-LHC Optics for Improved Performance of the Alice Fixed-Target Layout target, proton, collimation, optics 108
 
  • M. Patecki, D. Kikoła
    Warsaw University of Technology, Warsaw, Poland
  • A.S. Fomin, P.D. Hermes, D. Mirarchi, S. Redaelli
    CERN, Meyrin, Switzerland
 
  Funding: This project has received funding from the European Union’s Horizon 2020 research and innovation programme, grant agreement number 101003442 - FIXEDTARGETLAND.
The Large Hadron Collider (LHC) at the European Organization for Nuclear Research (CERN) is the world’s largest and most powerful particle accelerator colliding beams of protons and lead ions at energies up to 7 TeV and 2.76 TeV, respectively. ALICE is one of the detector experiments optimised for heavy-ion collisions. A fixed-target experiment in ALICE is considered to collide a portion of the beam halo, split using a bent crystal, with an internal target placed a few meters upstream of the detector. Fixed-target collisions offer many physics opportunities related to hadronic matter and the quark-gluon plasma to extend the research potential of the CERN accelerator complex. Production of physics events depends on the particle flux on target. The machine layout for the fixed-target experiment is being developed to provide a flux of particles on a target high enough to exploit the full capabilities of the ALICE detector acquisition system. In this paper, we discuss a method of increasing the system’s performance by applying a local modification of optics to set the crystal at the optimal betatron phase.
marcin.patecki@pw.edu.pl
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOST024  
About • Received ※ 08 June 2022 — Revised ※ 09 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 01 July 2022
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MOPOST025 Influences of the Transverse Motions of the Particles to the Recombination Rate of a Co-Propagating Electron-Ion System electron, alignment, target, cavity 112
 
  • G. Wang, D. Kayran, V. Litvinenko, I. Pinayev, P. Thieberger
    BNL, Upton, New York, USA
  • V. Litvinenko
    Stony Brook University, Stony Brook, USA
 
  Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy.
For a system with the ion beam co-propagating with the electron beam, such as a traditional electron cooler or a Coherent electron Cooler (CeC), the recombination rate is an important observable for matching the energy of the electrons with the ions. In this work, we have developed the analytical expressions to investigate how the recombination rate depends on the energy difference of the two beams, with the influences from the transverse motions of the particles being considered. The analytical results are then used to analyze the measured recombination data collected during the CeC experiment in run 21 and run 22.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOST025  
About • Received ※ 09 June 2022 — Revised ※ 10 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 27 June 2022
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MOPOST026 Influences of the Energy Jitter to the Performance of the Coherent Electron Cooling electron, simulation, kicker, emittance 115
 
  • G. Wang, V. Litvinenko, J. Ma
    BNL, Upton, New York, USA
  • V. Litvinenko
    Stony Brook University, Stony Brook, USA
 
  Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy.
The bandwidth of a coherent electron cooling (CeC) system is typically two to three orders of magnitude higher than the traditional RF based stochastic cooling system, which make it possible to cool the ion bunches with high energy and high intensity. However, for such broad bandwidth, jitters in the energy of the cooling electron bunches present a serious challenge to the performance of the cooling system. In this work, we present analytical as well as simulation studies about the influences of the energy jitter to a CeC system with parameters relevant to the on-going CeC experiment at RHIC.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOST026  
About • Received ※ 09 June 2022 — Revised ※ 10 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 29 June 2022
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MOPOST033 Betatron Tune Characterization of the Rutgers 12-Inch Cyclotron for Different Magnetic Poles Configurations focusing, cyclotron, betatron, HOM 136
 
  • C. Hernalsteens
    CERN, Meyrin, Switzerland
  • B.L. Beaudoin, T.W. Koeth
    UMD, College Park, Maryland, USA
  • M. Miller
    Brown University, Providence, USA
  • T.S. Ponter
    IBA, Louvain-la-Neuve, Belgium
  • K.J. Ruisard
    ORNL, Oak Ridge, Tennessee, USA
  • R. Tesse
    ULB, Bruxelles, Belgium
 
  The Rutgers cyclotron is a small 12-Inch, 1.2MeV proton cyclotron. Sets of magnet pole-tips were designed to demonstrate different cyclotron focusing options: weak focusing, radial sector focusing and spiral sector focusing. The purpose of this paper is to experimentally characterize the transverse dynamics provided by different types of focusing. Magnetic field measurements provide insight into the as-built properties of these magnetic poles configurations. First we discuss the axial betatron tune measurements as a function of the beam energy towards outer radii, which agree well with the values expected from measured magnetic data. Turn-by-turn betatron envelope oscillation measurements are also reported and compared with the tune measurements. Excellent agreement is once again found.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOST033  
About • Received ※ 09 June 2022 — Revised ※ 14 June 2022 — Accepted ※ 14 June 2022 — Issue date ※ 08 July 2022
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MOPOST035 Operational Experience and Performance of the REX/HIE-ISOLDE Linac ISOL, linac, operation, MMI 140
 
  • J.A. Rodriguez, N. Bidault, E. Fadakis, P. Fernier, M.L. Lozano, S. Mataguez, E. Piselli, E. Siesling
    CERN, Meyrin, Switzerland
 
  Located at CERN, ISOLDE is one of the world’s lead-ing research facilities in the field of nuclear science. Radioactive Ion Beams (RIBs) are produced when 1.4 GeV protons transferred from the Proton Synchrotron Booster (PSB) to the facility impinge on one of the two available targets. The RIB of interest is extracted, mass-separated and transported to one of the experimental stations, either directly, or after being accelerated in the REX/HIE-ISOLDE post-accelerator. In addition to a Penning trap (REXTRAP) to accumulate and transversely cool the beam and a charge breeder (REXEBIS) to boost the charge state of the ions, the post-accelerator includes a linac with both room temperature (REX linac) and superconducting (HIE-ISOLDE linac) sections followed by three HEBT lines to deliver the beam to the different experimental stations. The latest upgrades of the facility as well as a comprehensive list of the RIBs delivered to the users of the facility and the operational experience gained during the last physics campaigns will be presented in this contribution.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOST035  
About • Received ※ 07 June 2022 — Revised ※ 12 June 2022 — Accepted ※ 13 June 2022 — Issue date ※ 21 June 2022
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MOPOST050 Third-Order Resonance Compensation at the FNAL Recycler Ring resonance, sextupole, proton, operation 195
 
  • C.E. Gonzalez-Ortiz
    MSU, East Lansing, Michigan, USA
  • R. Ainsworth
    Fermilab, Batavia, Illinois, USA
  • P.N. Ostroumov
    FRIB, East Lansing, Michigan, USA
 
  The Recycler Ring (RR) at the Fermilab Accelerator Complex performs slip-stacking on 8 GeV protons, doubling the beam intensity delivered to the Main Injector (MI). At MI, the beam is accelerated to 120 GeV and delivered to the high energy neutrino experiments. Femilab’s Proton Improvement Plan II (PIP-II) will require the Recycler to store 50% more beam. Simulations have shown that the space charge tune shift at this new intensity will lead to the excitation of multiple resonance lines. Specifically, this study looks at normal sextupole lines 3 Qx=76 and Qx+2Qy=74, plus skew sextupole lines 3 Qy=73 and 2 Qx+Qy=75. Dedicated normal and skew sextupoles have been installed in order to compensate for these resonance lines. By measuring and calculating the Resonance Driving Terms (RDT), this study shows how each of the resonance lines can be compensated independently. Furthermore, this study shows and discusses initial investigations into compensating multiple lines simultaneously.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOST050  
About • Received ※ 09 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 21 June 2022  
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MOPOST053 Transverse Resonance Islands Buckets at SPEAR3 kicker, lattice, resonance, feedback 203
 
  • J. Kim, J.A. Safranek, K. Tian
    SLAC, Menlo Park, California, USA
 
  We present populating bunches into the transverse resonance islands buckets (TRIBs) on SPEAR3. As one of operation modes for the timing-mode or providing separated bunches in transverse direction, we are exploring TRIBs on SPEAR3. Experience and analysis on applying kicks multiple times using the bunch-by-bunch feedback kicker to move bunches into the TRIBs is described.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOST053  
About • Received ※ 06 June 2022 — Revised ※ 09 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 03 July 2022
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MOPOPT002 Improvements on Sirius Beam Stability controls, operation, network, feedback 226
 
  • S.R. Marques, M.B. Alves, F.C. Arroyo, M.P. Calcanha, H.F. Canova, B.E. Limeira, L. Liu, R.T. Neuenschwander, A.G.C. Pereira, D.O. Tavares, F.H. de Sá
    LNLS, Campinas, Brazil
  • G.O. Brunheira, A.C.T. Cardoso, R.B. Cardoso, R. Junqueira Leão, L.R. Leão, P.H.S. Martins, Moreira, S.S. Moreira, R. Oliveira Neto, M.G. Siqueira
    CNPEM, Campinas, SP, Brazil
 
  Sirius is a Synchrotron Light Source based on a 3 GeV electron storage ring with 518 meters circumference and 250 pm.rad emittance. The facility is built and operated by the Brazilian Synchrotron Light Laboratory (LNLS), located in the CNPEM campus, in Campinas. A beam stability task force was recently created to identify and mitigate the orbit disturbances at various time scales. This work presents studies regarding ground motion (land subsidence caused by groundwater extraction), improvements in the temperature control of the storage ring (SR) tunnel air conditioning (AC) system, vibration measurements in accelerator components and the efforts concerning the reduction of the power supplies’ ripple. The fast orbit feedback implementation and other future perspectives will also be discussed.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOPT002  
About • Received ※ 08 June 2022 — Revised ※ 14 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 17 June 2022
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MOPOPT004 Development of a New Clusterization Method for the GEM-TPC Detector detector, electron, electronics, ECR 233
 
  • M. Luoma, F. Garcia, A. Jokinen, R. Turpeinen, J. Äystö
    HIP, University of Helsinki, Finland
  • T. Blatz, H. Flemming, K. Götzen, C. Karagiannis, N. Kurz, S. Löchner, C. Nociforo, C.J. Schmidt, H. Simon, B. Voss, P. Wieczorek, M. Winkler
    GSI, Darmstadt, Germany
  • D. Chokheli
    Georgian Technical University, Tbilisi, Georgia
  • T. Grahn, S. Rinta-Antila
    JYFL, Jyväskylä, Finland
 
  The Facility for Antiproton and Ion Research FAIR, in Darmstadt Germany, will be one of the largest accelerator laboratories worldwide. The Superconducting FRagment Separator (Super-FRS)* is one of its main components. The Super-FRS can produce, separate and deliver high-energy radioactive beams with intensities up to 1e11 ions/s, covering projectiles from protons up to uranium and it can be used as an independent experimental device. The Gas Electron Multiplier-based Time Projection Chambers (GEM-TPC) in twin configuration is a newly developed beam tracking detector capable of providing spatial resolution of less than 1 mm with a tracking efficiency close to 100% at 1 MHz counting rate. The GEM-TPC (HGB4) was tested at the FRagment Separator (FRS), with 238U beam at 850 MeV/u. A new clusterization method was developed, for the first time and used for an analysis. This method allowed to access to waveforms of each strip signal within a single trigger in an event-by-event basis. The procedures involved in this method will be shown in details.
* H.Geissel et al., The Super-FRS project at GSI, Nucl. Instr. and Meth. in Phys., vol. B204, pp. 71-85, 2003.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOPT004  
About • Received ※ 08 June 2022 — Revised ※ 13 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 23 June 2022
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MOPOPT010 Status of Diamond and LGAD Based Beam-Detectors for the mCBM and CBM Experiments at GSI and FAIR detector, monitoring, heavy-ion, proton 247
 
  • A. Rost, P.-A. Loizeau
    FAIR, Darmstadt, Germany
  • I. Deppner, N. Herrmann, E. Rubio
    Universität Heidelberg, Heidelberg, Germany
  • J. Frühauf, T. Galatyuk, M. Kis, J. Pietraszko, M. Träger, F. Ulrich-Pur
    GSI, Darmstadt, Germany
  • T. Galatyuk, V. Kedych, W. Krüger
    TU Darmstadt, Darmstadt, Germany
 
  Funding: This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No. 871072.
The Compressed Baryonic Matter (CBM) experiment* is currently under construction at the Facility for Antiproton and Ion Research (FAIR) in Darmstadt. The aim of the experiment is the exploration of the Quantum Chromodynamics (QCD) phase diagram of matter at high net-baryon densities and for moderate temperatures. In this contribution a beam monitoring (BMON) system will be presented which will include a high-speed time-zero (T0) detector. The detector system must meet the requirements of the CBM time-of-flight (ToF) measurement system for proton and heavy-ion beams and should also allow for beam monitoring. The detector technology is planned to be based on chemical vapor deposition (CVD) diamond basis but also new Low Gain Avalanche Detector (LGAD) developments are evaluated. In this contribution the beam detector concept will be presented and the results of first prototype tests in the mini-CBM setup will be shown.
*P. Senger, Exploring Cosmic Matter in the Laboratory - The Compressed Baryonic Matter Experiment at FAIR, Particles, vol. 2, no. 4, pp. 499-510, 2019.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOPT010  
About • Received ※ 08 June 2022 — Revised ※ 10 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 25 June 2022
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MOPOPT013 Comparative Study of Broadband Room Temperature THz Detectors for High and Intermediate Frequency Response detector, electron, laser, photon 257
 
  • R. Yadav, S. Preu
    IMP, TU Darmstadt, Darmstadt, Germany
  • A. Penirschke
    THM, Friedberg, Germany
 
  Funding: Scholarship from Hesse ministry of science and culture (HMWK), Germany.
Room temperature terahertz (THz) detectors based on Field effect transistors (FETs) and Zero-bias Schottky diodes (SD) are prominent members for the temporal-spatial characterization of pulses down to the picosecond scale generated at particle accelerators. Comparative study of in house developed THz detectors both at higher and intermediate frequency (IF) is carried out using table top THz systems and commercially available sources. In this paper, we present high frequency and intermediate frequency (IF) response of Gallium Arsenide (GaAs) FET and Zero-bias Schottky diode THz detectors. The IF results obtained are helpful for understanding and designing of optimized IF circuit with broader bandwidth.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOPT013  
About • Received ※ 19 May 2022 — Revised ※ 09 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 25 June 2022
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MOPOPT028 Beam Diagnostics and Instrumentation for MESA cavity, operation, diagnostics, instrumentation 307
 
  • M. Dehn, K. Aulenbacher, J. Diefenbach, F. Fichtner, P. Heil, R.G. Heine, R.F.K. Kempf, C. Matejcek
    IKP, Mainz, Germany
  • C.L. Lorey
    KPH, Mainz, Germany
 
  Funding: Work supported by PRISMA and the German federal state of Rheinland-Pfalz
For the new Mainz Energy recovering Superconducting Accelerator (MESA) a wide range of beam currents is going to be used during machine optimization and for the physics experiments. To be able to monitor beam parameters like beam current, phases and beam positions several different kinds of beam instrumentation is foreseen. Some components have already been tested at the Mainz Microtron (MAMI) and others have been used at the MELBA test accelerator. In this paper we will present the current status of the instrumentation.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOPT028  
About • Received ※ 08 June 2022 — Revised ※ 10 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 02 July 2022
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MOPOPT029 Longitudinal Phase Space Benchmarking for PITZ Bunch Compressor simulation, booster, FEL, laser 310
 
  • A. Lueangaramwong, Z. Aboulbanine, G.D. Adhikari, N. Aftab, P. Boonpornprasert, G.Z. Georgiev, J. Good, M. Groß, C. Koschitzki, M. Krasilnikov, X.-K. Li, O. Lishilin, D. Melkumyan, H.J. Qian, G. Shu, F. Stephan, G. Vashchenko, T. Weilbach
    DESY Zeuthen, Zeuthen, Germany
  • N. Chaisueb
    Chiang Mai University, Chiang Mai, Thailand
 
  The longitudinal phase space characteristics of space-charge dominated electron beams are keys to achieving bunch compression for the accelerator-based THz source at the Photo Injector Test facility at DESY in Zeuthen (PITZ). Such a THz source is proposed as a prototype for an accelerator-based THz source for pump-probe experiments at the European XFEL. A start-to-end simulation has suggested the settings of the phase of booster linear accelerator manipulating longitudinal beam characteristics to optimize the performance of the THz FEL. Although beam diagnostics after compression at PITZ are limited, the longitudinal beam characteristics as a function of the booster phase have been measured and compared with the corresponding simulations. The benchmark involves measurements of longitudinal phase space distribution for bunch charges up to 2 nC. The measurement technique assigned uses 50-um slits to achieve higher momentum and time resolution (1.8 keV/c and 0.5 ps, respectively).  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOPT029  
About • Received ※ 07 June 2022 — Revised ※ 10 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 18 June 2022
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MOPOPT033 Study of Cherenkov Diffraction Radiation for Beam Diagnostics radiation, electron, diagnostics, beam-diagnostic 320
 
  • H. Hama, K. Nanbu
    Tohoku University, Research Center for Electron Photon Science, Sendai, Japan
 
  Cherenkov diffraction radiation (ChDR) has been paid attention to non-beam-destructive diagnostics in these years. However, the physical understanding of ChDR is not well satisfied yet because of precise experimental observation is not much easier than one expects. Although we do not deny the Cherenkov radiation and ChDR are fully explained by the classical electromagnetics, we encounter a couple of difficulties in actual applications. For instance, the theory is usually established for the far-field observation, in spite of that the radiation is often observed near-field in the realistic beam diagnostic tools employing photon measurements. In addition, the theory, as a matter of course, includes some assumptions which is sometimes not valid for the specific experiments. We have carried out experiments for observation of coherent ChDR in THz frequency region by a using 100 femtosecond electron beam supplied by the t-ACTS accelerator at Tohoku University. In a flame work of this study an FDTD simulation in the large space has been developed as well. In this presentation, we will show the experimental results comparing with both the theory and the simulation.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOPT033  
About • Received ※ 08 June 2022 — Revised ※ 15 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 21 June 2022
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MOPOPT034 Surrogate-Based Bayesian Inference of Transverse Beam Distribution for Non-Stationary Accelerator Systems controls, beam-transport, framework, simulation 324
 
  • H. Fujii, N. Fukunishi
    RIKEN Nishina Center, Wako, Japan
  • M. Yamakita
    Tokyo Tech, Tokyo, Japan
 
  Constraints on the beam diagnostics available in real-time and time-varying beam source conditions make it difficult to provide users with high-quality beams for long periods without interrupting experiments. Although surrogate model-based inference is useful for inferring the unmeasurable, the system states can be incorrectly inferred due to manufacturing errors and neglected higher-order effects when creating the surrogate model. In this paper, we propose to adaptively assimilate the surrogate model for reconstructing the transverse beam distribution with uncertainty and underspecification using a sequential Monte Carlo from the measurements of quadrant beam loss monitors. The proposed method enables sample-efficient and training-free inference and control of the time-varying transverse beam distribution.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOPT034  
About • Received ※ 19 May 2022 — Accepted ※ 13 June 2022 — Issue date ※ 17 June 2022  
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPOPT037 Beam Measurement and Application of the Metal Vapor Vacuum Arc Ion Source at KOMAC radiation, ion-source, extraction, vacuum 328
 
  • S.H. Lee, H.S. Kim, H.-J. Kwon
    KOMAC, KAERI, Gyeongju, Republic of Korea
 
  Funding: This work has been supported through KOMAC operation fund of KAERI by MSIT (Ministry of Science and ICT) and the NRF (National Research Foundation) of Korea grant fund the Korea government (MSIT).
The metal ion beam facility is developed based on the MEVVA* ion source at the KOMAC**. The MEVVA ion source has advantage that it can be extract almost metal ion species as well as high current ion beam. After the installation, we measured beam properties such as peak beam current, beam profile depending on the operation condition. The average charge state is measured in order to estimate the total dose. We evaluate the beam stability through the long-term beam extraction, and the measured the cathode erosion rate too. In addition, as one of the application fields, we irradiate the metal beam on the cathode of the fuel cell and measured the performance. In this paper, the beam measurement results, are summarized and fuel cell performances after metal beam irradiation are discussed.
*Korea Multi-purpose of Accelerator Complex
**Metal Vapor Vacuum Arc
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOPT037  
About • Received ※ 08 June 2022 — Revised ※ 13 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 21 June 2022
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MOPOPT041 Artificial Intelligence-Assisted Beam Distribution Imaging Using a Single Multimode Fiber at CERN network, simulation, coupling, detector 339
 
  • G. Trad, S. Burger
    CERN, Meyrin, Switzerland
 
  In the framework of developing radiation tolerant imaging detectors for transverse beam diagnostics, the use of machine learning powered imaging using optical fibers is explored for the first time at CERN. This paper presents the pioneering work of using neural networks to reconstruct the scintillating screen beam image transported from a harsh radioactive environment over a single, large-core, multimode, optical fiber. Profiting from generative modeling used in image-to-image translation, conditional adversarial networks have been trained to translate the output plane of the fiber, imaged on a CMOS camera, into the beam image imprinted on the scintillating screen. Theoretical aspects, covering the development of the dataset via geometric optics simulations, modeling the image propagation in a simplified model of an optical fiber, and its use for training the network are discussed. Finally, the experimental setups, both in the laboratory and at the CLEAR facility at CERN, used to validate the technique and evaluate its potential are highlighted.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOPT041  
About • Received ※ 08 June 2022 — Revised ※ 14 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 19 June 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPOPT042 Recent AWAKE Diagnostics Development and Operational Results electron, proton, plasma, laser 343
 
  • E. Senes, S. Burger, M. Krupa, T. Lefèvre, S. Mazzoni, E. Poimenidou, A. Topaloudis, M. Wendt, G. Zevi Della Porta
    CERN, Meyrin, Switzerland
  • P. Burrows, C. Pakuza
    JAI, Oxford, United Kingdom
  • P. Burrows, C. Pakuza
    Oxford University, Physics Department, Oxford, Oxon, United Kingdom
  • D.A. Cooke
    UCL, London, United Kingdom
  • J. Wolfenden
    The University of Liverpool, Liverpool, United Kingdom
  • J. Wolfenden
    Cockcroft Institute, Warrington, Cheshire, United Kingdom
 
  The Advanced Wakefield Experiment (AWAKE) at CERN investigates the Plasma-Wakefield acceleration of electrons driven by a relativistic proton bunch. After successfully demonstrating the acceleration process in the AWAKE Run 1, the experiment has now started the Run 2. The AWAKE Run 2 consists of several experimental periods that aim to demonstrate the feasibility of the AWAKE concept beyond the acceleration experiment, showing its feasibility as accelerator for particle physics application. As part of these developments, a dramatic effort in improving the AWAKE instrumentation is sustained. This contribution reports on the current developments of the instrumentation pool upgrade, including the digital camera system for transverse beam profile measurement, beam halo measurement and the spectrometer upgrade studies. The studies on the development of high-frequency beam position monitors are also described.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOPT042  
About • Received ※ 08 June 2022 — Revised ※ 13 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 23 June 2022
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MOPOPT045 Beam Loss Localisation with an Optical Beam Loss Monitor in the CLEAR Facility at CERN beam-losses, photon, electron, detector 351
 
  • S. Benítez Berrocal, E. Effinger, J.C. Esteban Felipe, W. Farabolini, P. Korysko, A.T. Lernevall, B. Salvachúa
    CERN, Meyrin, Switzerland
  • M. Chen
    University of Huddersfield, Huddersfield, United Kingdom
 
  A prototype of a Beam Loss Monitor based on the detection of Cherenkov light in optical fibres is being developed to measure beam losses in the CERN Super Proton Synchrotron. Several testing campaigns have been planned to benchmark the simulations of the system and test the electronics in the CLEAR facility at CERN. During the first campaigns, the emission of Cherenkov light inside optical fibres and the photodetector characterisation were studied. Fibre-based Beam Loss monitors continuously monitor beam losses over long distances. The localisation of the beam loss could be calculated from the timing of the signals generated by the photosensors coupled at both ends of the optical fibre. The experimental results of an optical fibre Beam Loss Monitor installed in the CLEAR facility are reported in this paper.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOPT045  
About • Received ※ 03 June 2022 — Revised ※ 12 June 2022 — Accepted ※ 13 June 2022 — Issue date ※ 24 June 2022
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MOPOPT048 Design of a Prototype Gas Jet Profile Monitor for Installation Into the Large Hadron Collider at CERN electron, proton, vacuum, photon 363
 
  • R. Veness, M. Ady, C. Castro Sequeiro, T. Lefèvre, S. Mazzoni, I. Papazoglou, A. Rossi, G. Schneider, O. Sedláček, K. Sidorowski
    CERN, Meyrin, Switzerland
  • P. Forck, S. Udrea
    GSI, Darmstadt, Germany
  • N. Kumar, A. Salehilashkajani, O. Sedláček, C.P. Welsch, H.D. Zhang
    Cockcroft Institute, Warrington, Cheshire, United Kingdom
  • N. Kumar, A. Salehilashkajani, O. Sedláček, O. Stringer, C.P. Welsch, H.D. Zhang
    The University of Liverpool, Liverpool, United Kingdom
 
  The Beam-Gas Curtain or BGC is the baseline instrument for monitoring the concentricity of the LHC proton beam with a hollow electron beam for the hollow e-lens (HEL) beam halo suppression device which is part of the High-Luminosity LHC upgrade. The proof-of-principles experiments of this gas-jet monitor have now been developed into a prototype instrument which has been built for integration into the LHC ring and is now under phased installation for operation in the upcoming LHC run. This paper describes the challenges overcome to produce a gas-jet fluorescence monitor for the ultra-high vacuum accelerator environment. It also presents preliminary results from the installation of the instrument at CERN.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOPT048  
About • Received ※ 07 June 2022 — Revised ※ 10 June 2022 — Accepted ※ 13 June 2022 — Issue date ※ 17 June 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPOPT053 A Beam Position Monitor for Electron Bunch Detection in the Presence of a More Intense Proton Bunch for the AWAKE Experiment electron, proton, plasma, radiation 381
 
  • C. Pakuza, P. Burrows
    Oxford University, Physics Department, Oxford, Oxon, United Kingdom
  • P. Burrows, C. Pakuza
    JAI, Oxford, United Kingdom
  • R. Corsini, W. Farabolini, P. Korysko, M. Krupa, T. Lefèvre, S. Mazzoni, E. Senes, M. Wendt
    CERN, Meyrin, Switzerland
 
  The Advanced Proton Driven Plasma Wakefield Experiment (AWAKE) at CERN uses 6 cm long proton bunches extracted from the Super Proton Synchrotron (SPS) at 400 GeV beam energy to drive high gradient plasma wakefields for the acceleration of electron bunches to 2 GeV within a 10 m length. Knowledge and control of the position of both copropagating beams is crucial for the operation of the experiment. Whilst the current electron beam position monitoring system at AWAKE can be used in the absence of the proton beam, the proton bunch signal dominates when both particle bunches are present simultaneously. A new technique based on the generation of Cherenkov diffraction radiation (ChDR) in a dielectric material placed in close proximity to the particle beam has been designed to exploit the large bunch length difference of the particle beams at AWAKE, 200 ps for protons versus a few ps for electrons, such that the electron signal dominates. Hence, this technique would allow for the position measurement of a short electron bunch in the presence of a more intense but longer proton bunch. The design considerations, numerical analysis and plans for tests at the CERN Linear Electron Accelerator for Research (CLEAR) facility are presented.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOPT053  
About • Received ※ 20 May 2022 — Revised ※ 09 June 2022 — Accepted ※ 10 June 2022 — Issue date ※ 17 June 2022
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MOPOPT054 A Modified Nomarski Interferometer to Study Supersonic Gas Jet Density Profiles laser, vacuum, optics, diagnostics 385
 
  • C. Swain, O. Apsimon, A. Salehilashkajani, C.P. Welsch, J. Wolfenden, H.D. Zhang
    Cockcroft Institute, Warrington, Cheshire, United Kingdom
  • Ö. Apsimon, A. Salehilashkajani, C. Swain, C.P. Welsch, J. Wolfenden, H.D. Zhang
    The University of Liverpool, Liverpool, United Kingdom
 
  Funding: This work is supported by the AWAKE-UK phase II project grant No. ST/T001941/1, the STFC Cockcroft core grant No. ST/G008248/1 and the HL-LHC-UK phase II project funded by STFC under Grant Ref: ST/T001925/1.
Gas jet-based non-invasive beam profile monitors, such as those developed for the high luminosity Large Hadron Collider (HL-LHC) upgrade, require accurate, high resolution methods to characterise the supersonic gas jet density profile. This paper proposes a modified Nomarski interferometer to non-invasively study the behaviour of these jets, with nozzle diameters of 1 mm or less in diameter. It discusses the initial design and results, alongside plans for future improvements. Developing systems such as this which can image on such a small scale allows for improved monitoring of supersonic gas jets used in several areas of accelerator science, thus allowing for improvements in the accuracy of experiments they are utilised in.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOPT054  
About • Received ※ 08 June 2022 — Revised ※ 10 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 03 July 2022
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MOPOPT055 A Gas Jet Beam Profile Monitor for Beam Halo Measurement simulation, electron, background, diagnostics 389
 
  • O. Stringer, N. Kumar, C.P. Welsch, H.D. Zhang
    The University of Liverpool, Liverpool, United Kingdom
  • N. Kumar, C.P. Welsch, H.D. Zhang
    Cockcroft Institute, Warrington, Cheshire, United Kingdom
 
  Funding: This work was supported by the HL-LHC-UK phase II project funded by STFC under Grant Ref: ST/T001925/1 and the STFC Cockcroft Institute core grant No. ST/G008248/1.
The gas jet beam profile monitor is a non-invasive beam monitor that is currently being commissioned at Cockcroft Institute. It utilises a supersonic gas curtain which transverses the beam at an angle of 45 degrees and measures beam-induced ionisation interactions of the gas to produce a 2D transverse beam profile image. This paper builds upon previously used single-slit skimmers and improves their ability to form the gas jet into a desired distribution for imaging beam halo. A skimmer device removes off-momentum gas particles and forms the jet into a dense thin curtain, suitable for transverse imaging of the beam. The use of a novel double-slit skimmer is shown to provide a mask-like void of gas over the beam core, increasing the relative intensity of the halo interactions for measurement. Such a non-invasive monitor would be beneficial to storage rings by providing real time beam characteristic measurements without affecting the beam. More specifically, beam halo behaviour is a key characteristic associated with beam losses within storage rings.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOPT055  
About • Received ※ 08 June 2022 — Revised ※ 09 June 2022 — Accepted ※ 26 June 2022 — Issue date ※ 26 June 2022
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MOPOPT057 Updates in Efforts to Data Science Enabled MeV Ultrafast Electron Diffraction System electron, network, gun, laser 397
 
  • S. Biedron, T.B. Bolin, M. Martínez-Ramón, S.I. Sosa Guitron
    UNM-ECE, Albuquerque, USA
  • M. Babzien, M.G. Fedurin, J.J. Li, M.A. Palmer
    BNL, Upton, New York, USA
  • S. Biedron
    UNM-ME, Albuquerque, New Mexico, USA
  • D. Martin, M.E. Papka
    ANL, Lemont, Illinois, USA
 
  Funding: Work supported by DOEs EPSCoR award DE-SC0021365, used resources of the Brookhaven National Laboratory’s Accelerator Test Facility and of the Argonne Leadership Computing Facility.
MeV ultrafast electron diffraction (MUED) is a pump-probe characterization technique to study ultrafast phenomena in materials with high temporal and spatial resolution. This complex instrument can be advanced into a turn-key, high-throughput tool with the aid of machine learning (ML) mechanisms and high-performance computing. The MUED instrument at the Accelerator Test Facility in Brookhaven National Laboratory was employed to test different ML approaches for both data analysis and control. We characterized different materials using MUED, mainly polycrystalline gold and single crystal Ta2NiS5. Diffraction patterns were acquired in single shot mode and convolutional neural network autoenconder models were evaluated for noise reduction and the reconstruction error was studied to identify anomalous diffraction patterns. Electron beam energy jitter was analyzed from single shot diffraction patterns to be used as a novel diagnostic tool. The MUED beamline was also simulated using VSim to construct a surrogate model for control of beam shape and energy. Progress towards ML-based controls leveraging off Argonne Leadership Computing Facility resources will also be presented.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOPT057  
About • Received ※ 02 July 2022 — Accepted ※ 26 June 2022 — Issue date ※ 08 July 2022  
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MOPOPT058 Machine Learning Training for HOM Reduction in a TESLA-Type Cryomodule at FAST HOM, cavity, electron, emittance 400
 
  • J.A. Diaz Cruz
    UNM-ECE, Albuquerque, USA
  • J.A. Diaz Cruz, A.L. Edelen, B.T. Jacobson, J.P. Sikora
    SLAC, Menlo Park, California, USA
  • D.R. Edstrom, A.H. Lumpkin, R.M. Thurman-Keup
    Fermilab, Batavia, Illinois, USA
 
  Low emittance electron beams are of high importance at facilities like the Linac Coherent Light Source II (LCLS-II) at SLAC. Emittance dilution effects due to off-axis beam transport for a TESLA-type cryomodule (CM) have been shown at the Fermilab Accelerator Science and Technology (FAST) facility. The results showed the correlation between the electron beam-induced cavity high-order modes (HOMs) and the Beam Position Monitor (BPM) measurements downstream the CM. Mitigation of emittance dilution can be achieved by reducing the HOM signals. Here, we present a couple of Neural Networks (NN) for bunch-by-bunch mean prediction and standard deviation prediction for BPMs located downstream the CM.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOPT058  
About • Received ※ 15 June 2022 — Revised ※ 18 June 2022 — Accepted ※ 24 June 2022 — Issue date ※ 26 June 2022
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MOPOPT062 Foil Focusing Effect in Pepper-Pot Measurements in Intense Electron Beams emittance, focusing, electron, solenoid 404
 
  • S. Szustkowski, M.A. Jaworski, D.C. Moir
    LANL, Los Alamos, New Mexico, USA
 
  Funding: Work supported by the US Department of Energy through the Los Alamos National Laboratory. Los Alamos National Laboratory is operated by Triad National Security, LLC, for the National Nuclear Security Administration of the U.S. Department of Energy (Contract No. 89233218CNA000001).
Thin conducting foils, such as pepper-pot masks, perpendicular to an oncoming intense electron beam acts like an imperfect axisymmetric lens. The beamlets distribution from a pepper-pot mask varies based on if the mask hole radius is smaller or larger than the beams Debye length. Correcting for focusing effect is necessary for measuring transverse emittance with pepper-pot technique for intense electron beams. The Dual Axis Radiographic Hydrodynamic Test Facility (DARHT) Axis-I produces a 20 MeV, 2 kA, 80 ns FWHM electron beam for flash radiography. In this paper, we explore the effect of foil focusing due to various pepper-pot masks at DARHT Axis-I injector region from a 55 mm velvet cathode.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOPT062  
About • Received ※ 01 June 2022 — Revised ※ 11 June 2022 — Accepted ※ 14 June 2022 — Issue date ※ 16 June 2022
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MOPOPT066 Gas Sheet Diagnostics Using Particle in Cell Code electron, simulation, diagnostics, plasma 410
 
  • M. Yadav, P. Manwani, J.B. Rosenzweig
    UCLA, Los Angeles, California, USA
  • G. Andonian
    RadiaBeam, Santa Monica, California, USA
  • Ö. Apsimon, C.P. Welsch
    The University of Liverpool, Liverpool, United Kingdom
  • N.M. Cook, A. Diaw, C.C. Hall
    RadiaSoft LLC, Boulder, Colorado, USA
  • N.P. Norvell
    UCSC, Santa Cruz, California, USA
 
  Funding: This work was supported by the STFC Liverpool Centre for Doctoral Training on Data Intensive Science (LIV. DAT) under grant agreement ST/P006752/1 and DE-SC0019717.
When intense particle beam propagates in dense plasma or gas, ionization can yield valuable information on the drive beam properties. Impact ionization and tunnel ionization are the two ionization regimes that must be accounted for varying beam properties. Due to these ionization mechanisms, new plasma electrons are generated causing different instabilities, dependent on the dominant ionization process considered. In order to accomplish the ambitious experimental goals of sophisticated beam diagnostics using ionization imaging, careful studies on the different ionization regimes, and the cross-over periods, required. Here we will discuss the impact ionization using fully parallel PIC code OSIRIS. We focus on understanding the gas sheet ionization diagnostics for characterizing high intensity charged particle beams. We study the interaction of neutral gas with an electron beam and varying density. We will also investigate the principle of detecting photon emission, rather than direct primary ion imaging, from the ionization induced in the interaction between the gas jet and charged particle beams.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOPT066  
About • Received ※ 07 June 2022 — Revised ※ 19 June 2022 — Accepted ※ 21 June 2022 — Issue date ※ 26 June 2022
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MOPOPT067 Electron Beam Phase Space Reconstruction From a Gas Sheet Diagnostic simulation, electron, diagnostics, network 414
 
  • N.M. Cook, A. Diaw, C.C. Hall
    RadiaSoft LLC, Boulder, Colorado, USA
  • G. Andonian
    RadiaBeam, Santa Monica, California, USA
  • N.P. Norvell
    UCSC, Santa Cruz, California, USA
  • M. Yadav
    The University of Liverpool, Liverpool, United Kingdom
 
  Funding: This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of High Energy Physics under Award Number DE-SC0019717.
Next generation particle accelerators craft increasingly high brightness beams to achieve physics goals for applications ranging from colliders to free electron lasers to studies of nonperturbative QED. Such rigorous requirements on total charge and shape introduce diagnostic challenges for effectively measuring bunch parameters prior to or at interaction points. We report on the simulation and training of a non-destructive beam diagnostic capable of characterizing high intensity charged particle beams. The diagnostic consists of a tailored neutral gas curtain, electrostatic microscope, and high sensitivity camera. An incident electron beam ionizes the gas curtain, while the electrostatic microscope transports generated ions to an imaging screen. Simulations of the ionization and transport process are performed using the Warp code. Then, a neural network is trained to provide accurate estimates of the initial electron beam parameters. We present initial results for a range of beam and gas curtain parameters and comment on extensibility to other beam intensity regimes.

 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOPT067  
About • Received ※ 08 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 10 July 2022  
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MOPOPT069 A Data-Driven Beam Trajectory Monitoring at the European XFEL FEL, lattice, undulator, operation 418
 
  • A. Sulc, R. Kammering, T. Wilksen
    DESY, Hamburg, Germany
 
  Funding: This work was supported by HamburgX grant LFF-HHX-03 to the Center for Data and Computing in Natural Sciences (CDCS) from the Hamburg Ministry of Science, Research, Equalities and Districts.
Interpretation of data from beam position monitors is a crucial part of the reliable operation of European XFEL. The interpretation of beam positions is often handled by a physical model, which can be prone to modeling errors or can lead to the high complexity of the computational model. In this paper, we show two data-driven approaches that provide insights into the operation of the SASE beamlines at European XFEL. We handle the analysis as a data-driven problem, separate it from physical peculiarities and experiment with available data based only on our empirical evidence and the data.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOPT069  
About • Received ※ 06 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 20 June 2022  
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MOPOTK001 The Influence of Solenoid Field on Off-Axis Travelling Beam in AREAL Accelerator solenoid, laser, alignment, simulation 422
 
  • H. Davtyan
    CANDLE, Yerevan, Armenia
  • G.A. Amatuni, A.A. Asoyan, A. Grigoryan, M.G. Yazichyan
    CANDLE SRI, Yerevan, Armenia
  • A. Grigoryan
    YSU, Yerevan, Armenia
 
  A wide range of experiments are being held at AREAL accelerator in the fields of materials science and life sci-ence by generating ultra-short 5 MeV electron beams. Beam parameter formation and stability preservation during the experiments are one of the key tasks of stable operation of the accelerator. Laser spot displacement on the photocathode could be one of the beam parameter distortion sources, which causes off-axis bunch travel also through the solenoid. The influences of laser spot horizontal displacement and the solenoid horizontal misalignment on the beam position at the experiment location are investigated separately via computer simulations. Using a laser spot mover and solenoid movers, an experiment has been carried out to compare simulation results with experiment.
*davtyan@asls.candle.am
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOTK001  
About • Received ※ 07 June 2022 — Revised ※ 10 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 02 July 2022
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MOPOTK003 Absorbed Dose Characteristics for Irradiation Experiments at AREAL 5 MeV Electron Linac electron, radiation, simulation, gun 429
 
  • V.G. Khachatryan, Z. Amirkhanyan, H. Davtyan, A. Grigoryan, B. Grigoryan, M. Ivanyan, V.H. Petrosyan, A. Vardanyan, A.S. Yeremyan
    CANDLE SRI, Yerevan, Armenia
  • A. Grigoryan
    YSU, Yerevan, Armenia
 
  Existing electron photogun facility at the CANDLE SRI currently can provide electron beam with the energy up to 5 MeV. The beam is being used as an irradiation source in the number of material science and life science experiments. Performed beam particle tracking simulations along with intensive application of the beam diagnostic instruments (bending magnet, YAG stations, Faraday cups) allow control of the experimental samples’ irradiation parameters, particularly exposure times for given dose as well as absorbed dose spatial distribution. Direct application of the electron beam for the irradiation experiments allows achievement of high absorbed dose. For the calculation of the irradiation parameters of the experimental samples’ particle transport simulation results should be combined with the beam current measurements by Faraday Cup (FC). Dose measurements and the comparison with numerical simulations using various initial parameters (Transverse size, divergence and energy spread) permit to pin down their actual values.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOTK003  
About • Received ※ 03 June 2022 — Revised ※ 10 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 02 July 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPOTK012 Concept of a Polarized Positron Source for CEBAF positron, electron, target, cavity 457
 
  • S.H. Habet, R.M. Bodenstein, S.A. Bogacz, J.M. Grames, A.S. Hofler, R. Kazimi, F. Lin, M. Poelker, Y. Roblin, A. Seryi, R. Suleiman, A.V. Sy, D.L. Turner
    JLab, Newport News, Virginia, USA
  • A. Ushakov
    Université Paris-Saclay, CNRS/IN2P3, IJCLab, Orsay, France
  • C.A. Valerio-Lizárraga
    ECFM-UAS, Culiacan, Sinaloa, Mexico
  • E.J-M. Voutier
    LPSC, Grenoble Cedex, France
 
  Funding: Laboratoire de Physique des 2 Infinis Irène Joliot-Curie Université Paris-Saclay -> Eric Voutier : eric.voutier@ijclab.in2p3.fr.
Positron beams would provide new and meaningful probes for the experimental program at the Thomas Jefferson National Accelerator Facility (JLab), including but not limited to future hadronic physics and dark matter experiments. Critical requirements involve generating positron beams with a high degree of spin polarization, sufficient intensity and a continuous-wave (CW) bunch train compatible with acceleration to 12 GeV at the Continuous Electron Beam Accelerator Facility (CEBAF). To address these requirements, a polarized positron injector based upon the bremsstrahlung of an intense CW spin polarized electron beam is considered*. First a polarized electron beam line provides >1 mA of polarized electrons at ~120 MeV to a high-power target for positron production. Next, a second beam line collects, shapes and aligns the spin of positrons for users. Finally, the positron beam is matched into the CEBAF acceptance for acceleration and transport to the end stations with energies up to 12 GeV. An optimized layout to provide positrons beams with intensity >100 nA (polarized) or intensity >3 µA (unpolarized) will be discussed in this poster.
* D. Abbott et al., "Production of Highly Polarized Positrons Using Polarized Electrons at MeV Energies", Phys. Rev. Lett., 116, 214801 (2016)
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOTK012  
About • Received ※ 08 June 2022 — Revised ※ 13 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 06 July 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPOTK014 Optics of a Recirculating Beamline for MESA target, optics, injection, scattering 465
 
  • C.P. Stoll, A. Meseck
    KPH, Mainz, Germany
 
  The Mainz Energy-recovering Superconducting Accelerator (MESA) is an Energy Recovery Linac (ERL) facility under construction at the Johannes Gutenberg-University in Mainz. It provides the opportunity for precision physics experiments with a 1 mA c.w. electron beam in its initial phase. In this phase experiments with unpolarised, high-density 1019 atoms per cm2 gas jet targets are foreseen at the Mainz Gas Internal Target Experiment (MAGIX). To allow experiments with thin polarised gas targets with sufficiently high interaction rates in a later phase, the beam current must be increased to up to 100 mA, which would pose significant challenges to the existing ERL machine. Thus, it is proposed here to use MESA in pulsed operation with a repetition rate of several kHz to fill a recirculating beamline, providing a quasi c.w. beam current to a thin gas target. The optics necessary for this recirculating beamline are presented here.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOTK014  
About • Received ※ 01 June 2022 — Revised ※ 10 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 07 July 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPOTK033 Beamline Design and Optimisation for High Intensity Muon Beams at PSI target, proton, dipole, solenoid 523
 
  • E.V. Valetov
    PSI, Villigen PSI, Switzerland
 
  Funding: This project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No. 884104 (PSI-FELLOW-III-3i).
The High Intensity Muon Beams (HIMB) project at the Paul Scherrer Institute (PSI) will provide muon intensities of the order of 1e10 muons/s for particle physics and material science experiments, two orders of magnitude higher than the state of the art, which is currently available also at PSI. In particle transport simulations for the HIMB, we use G4beamline with measured pi+ cross-sections and with variance reduction. We also use the codes COSY INFINITY, TRANSPORT, and TURTLE for some studies. We perform asynchronous Bayesian optimisation of the beamlines on a computing cluster using G4beamline and the optimisation package DeepHyper. We performed numerous studies for the design of the HIMB, and we produced various results, including the muon transmission, beam phase space, polarisation, and momentum spectrum.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOTK033  
About • Received ※ 16 May 2022 — Revised ※ 08 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 08 July 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPOTK035 Beam-Based Diagnostics of Electric Guide Fields and Lattice Parameters for Run-1 of the Muon g-2 Storage Ring at Fermilab storage-ring, detector, lattice, dipole 531
 
  • D.A. Tarazona, M. Berz, K. Makino
    MSU, East Lansing, Michigan, USA
  • J.D. Crnkovic, M.J. Syphers
    Fermilab, Batavia, Illinois, USA
  • K.S. Khaw
    Shanghai Jiao Tong University, Shanghai, People’s Republic of China
  • J. Mott
    BUphy, Boston, Massachusetts, USA
  • J. Price
    The University of Liverpool, Liverpool, United Kingdom
  • M.J. Syphers
    Northern Illinois University, DeKalb, Illinois, USA
  • D.A. Tarazona
    Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
  • V. Tishchenko
    BNL, Upton, New York, USA
 
  Funding: Fermi National Accelerator Laboratory (Fermilab) resources, a US DoE, Office of Science, HEP User Facility. Fermilab is managed by Fermi Research Alliance under Contract No. DE-AC02-07CH11359.
A portion of the Muon g-2 Storage Ring electric system, which provides vertical beam focusing, exhibited an unexpected time dependence that produced a characteristic evolution of the stored beam during Run-1 of the Muon g-2 Experiment at Fermilab (E989). A method to reconstruct the Run-1 electric guide fields has been developed, which is based on a numerical model of the muon storage ring and optimization algorithms supported by COSY INFINITY. This method takes beam profile measurements from the Muon g-2 straw tracking detectors as input, and it produces a full reconstruction of the time-dependent fields. The fields can then be used for the reproduction of detailed beam tracking simulations and the calculation of ring lattice parameters for acceptance studies and systematic error evaluations.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOTK035  
About • Received ※ 08 June 2022 — Revised ※ 12 June 2022 — Accepted ※ 23 June 2022 — Issue date ※ 25 June 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPOTK045 Generation of High Emittance Ratios in High Charge Electron Beams at FACET-II emittance, quadrupole, laser, cathode 560
 
  • O. Camacho
    UCLA, Los Angeles, USA
  • A. Halavanau, R. Robles
    SLAC, Menlo Park, California, USA
 
  Funding: DE-SC0009914
Experiments foreseen at FACET-II, including dielectric plasma wakefield acceleration and linear collider tests, call for electron beams with highly asymmetric transverse emittances - so called "flat beams". A canonical recipe for the generation of such beams is injecting a magnetized beam at a waist into an appropriately tuned skewed quadrupole triplet channel. However, due to the intense non-linear space-charge forces that dominate nC bunches, this method presents difficulties in maintaining the flatness. We proceed with generalized round-to-flat-beam (RTFB) transformation, which takes into account the non-negligible divergence of the beam at the channel entrance, using a quartet of skewed quadrupoles. Our analytical results are further optimized in ELEGANT and GPT simulation programs and applied to the case of the FACET-II beamline. Non-ideal cathode spot distributions obtained from recent FACET-II experiments are used for accurate numerical modeling. Tolerances to quadrupole strengths and alignment errors are also considered, with an eye towards developing hardware specifications.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOTK045  
About • Received ※ 03 June 2022 — Revised ※ 24 June 2022 — Accepted ※ 25 June 2022 — Issue date ※ 09 July 2022
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MOPOTK052 CEBAF Injector Model for KL Beam Conditions laser, simulation, gun, cathode 580
 
  • S. Pokharel, G.A. Krafft
    ODU, Norfolk, Virginia, USA
  • M.W. Bruker, J.M. Grames, A.S. Hofler, R. Kazimi, G.A. Krafft, S. Zhang
    JLab, Newport News, Virginia, USA
 
  Funding: This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics under contract DE-AC05-06OR23177.
The Jefferson Lab KL experiment will run at the Continuous Electron Beam Accelerator Facility with a much lower bunch repetition rate (7.80 or 15.59 MHz) than nominally used (249.5 or 499 MHz). While the proposed average current of 2.5 - 5.0 muA is relatively low compared to the maximum CEBAF current of approximately 180 muA, the corresponding bunch charge is atypically high for CEBAF injector operation. In this work, we investigated the evolution and transmission of low-rep-rate, high-bunch-charge (0.32 to 0.64 pC) beams through the CEBAF injector. Using the commercial software General Particle Tracer, we have simulated and analyzed the beam characteristics for both values of bunch charge. We performed these simulations with the existing injector using a 130 kV gun voltage. We have calculated and measured the transmission as a function of the photocathode laser spot size and pulse length. We report on the findings of these simulations and optimum parameters for operating the experiment.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOTK052  
About • Received ※ 07 June 2022 — Accepted ※ 12 June 2022 — Issue date ※ 26 June 2022  
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPOTK062 Numerical Calibration of the Bead-Pull Setup for Beam Coupling Impedance Evaluation cavity, impedance, simulation, coupling 607
 
  • D.M.F. El Dali, E. Métral, C. Zannini
    CERN, Meyrin, Switzerland
  • G. De Michele, S. Fanella
    AVO-ADAM, Meyrin, Switzerland
 
  The bead-pull method is a commonly used electromagnetic field measurement technique exploited to tune a radiofrequency cavity to achieve design specifications. The frequency of a resonant cavity is perturbed by inserting a metallic or dielectric bead. For a given electromagnetic field, the amplitude of the perturbation depends only on the geometry of the perturbing object. Therefore, the calibration of the bead can be done in different resonant structures without loss of generality. In this paper, a method to perform an accurate calibration of the bead with electromagnetic simulations is proposed. Compared to the common practice of measuring a reference cavity, the flexibility given by the simulation method to study different bead shapes and sizes could be advantageous to optimize the measurement setup. A calibrated bead-pull setup allows to quantify the electric field and, therefore, the shunt impedance of the resonant modes of the cavity. As experimental benchmark, the beam coupling impedance measured with the calibrated bead-pull setup is compared with electromagnetic simulations.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOTK062  
About • Received ※ 07 June 2022 — Revised ※ 11 June 2022 — Accepted ※ 20 June 2022 — Issue date ※ 20 June 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPOTK067 High-Charge Transmission Diagnostics for Beam-Driven RF Structures wakefield, diagnostics, acceleration, monitoring 618
 
  • E.E. Wisniewski, G. Chen, D.S. Doran, S.Y. Kim, W. Liu, X. Lu, J.G. Power, C. Whiteford
    ANL, Lemont, Illinois, USA
  • X. Lu, D.C. Merenich
    Northern Illinois University, DeKalb, Illinois, USA
  • F. Stulle
    BERGOZ Instrumentation, Saint Genis Pouilly, France
  • E.E. Wisniewski
    Illinois Institute of Technology, Chicago, Illinois, USA
 
  Funding: U.S. Department of Energy Office of Science Contract No. DE-AC02-06CH11357.
The Argonne Wakefield Accelerator group (AWA) has been using high Charge bunch-trains (>450 nC) for structure wakefield RF power generation and high power testing (100 s of MW) for many years. These experiments involve fast beam-tuning for high charge transmission through small aperture wakefield structures over a large range of charge levels. The success of these experiments depends on real-time, non-destructive, fast charge measurements with devices that are robust in the high-charge and high-powered RF environment. AWA uses Bergoz Integrating Charge Transformers (ICT) which are ideal for these critical charge measurements. The devices used, the method developed and its application are detailed.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOTK067  
About • Received ※ 08 June 2022 — Revised ※ 15 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 27 June 2022
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MOPOMS003 Single-Sided Pumped Compact Terahertz Driven Booster Accelerator electron, booster, gun, acceleration 625
 
  • T. Kroh, R. Bazrafshan, F.X. Kärtner, N.H. Matlis
    Deutsches Elektronen Synchrotron (DESY) and Center for Free Electron Science (CFEL), Hamburg, Germany
  • M. Fakhari, M. Pergament, T. Rohwer, M. Vahdani, D. Zhang
    CFEL, Hamburg, Germany
  • F.X. Kärtner
    The Hamburg Center for Ultrafast Imaging, University of Hamburg, Hamburg, Germany
  • K. Kawase
    JAEA, Kizugawa, Japan
 
  Funding: European Research Council under the European Union’s Seventh Framework Programme (FP7/2007-2013) through the Synergy Grant ’Frontiers in Attosecond X-ray Science: Imaging and Spectroscopy’ (609920).
Scaling the RF-accelerator concept to terahertz (THz) frequencies brings several compelling advantages, including compactness, intrinsic timing between the photoemission and driving field sources, and high field gradients associated with the short THz wavelength and high breakdown threshold. Recent demonstrations of such THz powered accelerators relied on two counter-propagating single-cycle THz pulses. However, to achieve high energy gains in the acceleration process high energy THz pulses are needed which in turn require complex optical setups. Here, we present on the development of a matchbox sized multi-layered accelerator designed to boost the 50 keV output of a DC electron gun to energies of ~400 keV that only requires a single THz pulse to be powered. An integrated tunable mirror inside the structure interferes the front of the driving THz pulse with its rear part such that the field in the interaction region is optimized for efficient acceleration. This reduces the complexity of the required optical setup. Such a compact booster accelerator is very promising as electron source in ultrafast electron diffraction experiments and as booster stage prior to THz based LINACs.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOMS003  
About • Received ※ 08 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 20 June 2022  
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPOMS013 Toward Emittance Measurements at 11.7 GHz Short-Pulse High-Gradient RF Gun gun, linac, emittance, GUI 649
 
  • S.V. Kuzikov, C.-J. Jing, E.W. Knight
    Euclid TechLabs, Solon, Ohio, USA
  • G. Chen, C.-J. Jing, P. Piot, E.E. Wisniewski
    ANL, Lemont, Illinois, USA
  • C.-J. Jing
    Euclid Beamlabs, Bolingbrook, USA
  • P. Piot
    Fermilab, Batavia, Illinois, USA
  • P. Piot, W.H. Tan
    Northern Illinois University, DeKalb, Illinois, USA
 
  Funding: This project is supported with DoE SBIR Phase II Grant #DE-SC0018709.
A short pulse high gradient RF gun has been recently tested at Argonne Wakefield Accelerator (AWA) facility. The carried-out test showed that the 1,5-cell gun was able to inject 3 MeV, up to 100 pC bunches at room tem-perature being fed by 9 ns up to 300 MW 11.7 GHz puls-es. The cathode field was as high as about 400 MV/m. So high field is aimed to mitigate repealing Coulomb forces substantially. In accordance with simulations the emit-tance could be as low as less than 0.2 mcm. To obtain so low emittance in the experiment, the gun is assumed to be equipped with a downstream linac to be fed from the same power extractor as the gun itself. Here we report design of the RF power distribution system splitting RF power among the gun and the linac, results of low-power tests, and emittance measurement plans for upcoming new experiment at AWA.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOMS013  
About • Received ※ 01 June 2022 — Revised ※ 09 June 2022 — Accepted ※ 18 June 2022 — Issue date ※ 01 July 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPOMS025 Photocathode Performance Characterisation of Ultra-Thin MgO Films on Polycrystalline Copper cathode, electron, emittance, photon 691
 
  • C. Benjamin, H.M. Churn, L.B. Jones, T.C.Q. Noakes
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
  • G.R. Bell, C. Benjamin, T.J. Rehaag
    University of Warwick, Coventry, United Kingdom
  • H.M. Churn, L.B. Jones, T.C.Q. Noakes
    Cockcroft Institute, Warrington, Cheshire, United Kingdom
 
  Funding: Department of Physics, The University of Warwick, Coventry, United Kingdom STFC ASTeC, Daresbury, Warrington, United Kingdom WA4 4AD
The performance expected from the next generation of electron accelerators is driving research into photocathode technology as this fundamentally limits the achievable beam quality. The performance characteristics of a photocathode are most notably; normalised emittance, brightness and energy spread*. Ultra–thin Oxide films on metal substrates have been shown to lower the work function (WF) of the surface, enhancing commonly utilised metal photocathodes, potentially improving lifetime and performance characteristics**. We present the characterisation of two MgO/Cu photocathodes grown at Daresbury. The surface properties such as; surface roughness, elemental composition and WF, have been studied using atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and ultraviolet photoelectron spectroscopy (UPS). The photoemissive properties have been characterised with quantum efficiency (QE) measurements at 266 nm. Additionally, we measure the Transverse Energy Distribution Curves (TEDC) for these photocathodes under illumination at various wavelengths using ASTeC’s Transverse Energy Spread Spectrometer (TESS) and extract the Mean Transverse Energy (MTE)***.
*D.H. Dowell, et al, Nucl. Instr. and Meth A (2010), doi:10.1016/j.nima.2010.03.104
**V. Chang, et al, Phys. Rev. B (2018), doi.org/10.1103/PhysRevB.97.155436
***Proc. FEL ’13, TUPPS033, 290-293
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOMS025  
About • Received ※ 19 May 2022 — Revised ※ 11 June 2022 — Accepted ※ 13 June 2022 — Issue date ※ 21 June 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPOMS042 Comparison Between Run 2 TID Measurements and FLUKA Simulations in the CERN LHC Tunnel of the Atlas Insertion Region radiation, simulation, operation, luminosity 732
 
  • D. Prelipcean, K. Biłko, F. Cerutti, A. Ciccotelli, D. Di Francesca, R. García Alía, B. Humann, G. Lerner, D. Ricci, M. Sabaté-Gilarte
    CERN, Meyrin, Switzerland
  • B. Humann
    TU Vienna, Wien, Austria
 
  In this paper we present a systematic benchmark between the simulated and the measured data for the radiation monitors useful for Radiation to Electronics (R2E) studies at the Large Hadron Collider (LHC) at CERN. For this purpose, the radiation levels in the main LHC tunnel on the right side of the Interaction Point 1 (ATLAS detector) are simulated using the FLUKA Monte Carlo code and compared against Total Ionising Dose (TID) measurements performed with the Beam Loss Monitoring (BLM) system, and 180 m of Distributed Optical Fibre Radiation Sensor (DOFRS). Considering the complexity and the scale of the simulations as well as the variety of the LHC operational parameters, we find a generally good agreement between measured and simulated radiation levels, typically within a factor of 2 or better.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOMS042  
About • Received ※ 08 June 2022 — Revised ※ 23 June 2022 — Accepted ※ 26 June 2022 — Issue date ※ 09 July 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPOMS052 6 MeV Novel Hybrid (Standing Wave - Traveling Wave) Photo-Cathode Electron Gun for a THz Superradiant FEL gun, electron, cathode, klystron 760
 
  • A. Nause, L. Feigin, A. Friedman, A. Weinberg
    Ariel University, Ariel, Israel
  • A. Fukasawa, J.B. Rosenzweig
    UCLA, Los Angeles, California, USA
  • B. Spataro
    LNF-INFN, Frascati, Italy
 
  A novel 6 MeV hybrid photo injector was designed and commissioned at Ariel University in Israel as an on-going collaboration with UCLA. This unique, new generation design provides a radically simpler approach to RF feeding of a gun/buncher system, leading to a much shorter beam via velocity bunching owed to an attached traveling wave section of the photo-injector. This design results in better performance in beam parameters, providing a high quality electron beam, with energy of 6 MeV, emittance of less than 3 ’m, and a 150 fs pulse duration at up to 1 nC per pulse. The Hybrid gun is driven by a SLAC XK5 Klystron as the high power RF source, and third harmonic of a fs level IR Laser amplifier (266 nm) to extract electrons from the Cathode. The unique e-gun will produce a bunched electron pulse to drive a THz FEL, which will operate at the super-radiance regime, and therefore requires extraordinary beam properties. It will also be used for MeV UED experiments in a separate line using a dogleg section. Here we describe the gun and presents experimental results from the gun and its sub-systems, including energy and charge measurements, compared with the design simulations.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOMS052  
About • Received ※ 11 June 2022 — Revised ※ 13 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 18 June 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPOST031 Online Optimization of the Transfer Line from UNILAC towards SIS18 at GSI Using a Genetic Autotune Algorithm simulation, injection, lattice, controls 922
 
  • S. Reimann
    GSI, Darmstadt, Germany
  • S. Reimann
    IAP, Frankfurt am Main, Germany
 
  Due to the complexity of GSI’s accelerator facilities and it’s upcoming expansion FAIR, various methods for optimizing accelerator settings are currently being studied to increase efficiency and to minimize the need for manual intervention. Besides a necessary improvement of the accelerator models, a better reproducibility of settings and the development of feedback systems, also heuristic methods are in the focus of the investigation. This work presents the results, recently achieved in optimizing the transfer line from UNILAC to SIS18 using the Autotune algorithm.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOST031  
About • Received ※ 18 May 2022 — Revised ※ 13 June 2022 — Accepted ※ 14 June 2022 — Issue date ※ 17 June 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPOST045 Overview of the Machine Learning and Numerical Optimiser Applications on Beam Transfer Systems for LHC and Its Injectors proton, extraction, kicker, alignment 961
 
  • F.M. Velotti, M.J. Barnes, E. Carlier, Y. Dutheil, M.A. Fraser, B. Goddard, N. Magnin, R.L. Ramjiawan, E. Renner, P. Van Trappen
    CERN, Meyrin, Switzerland
  • E. Waagaard
    Uppsala University, Uppsala, Sweden
 
  Machine learning and numerical optimisation algorithms are getting more and more popular in the accelerator physics community and, thanks to the computing power available, their application in daily operation more likely. In the CERN accelerator complex, and specifically on the beam transfer systems, many promising exploitation of these numerical tools have been put in place in the last years. Some of the state-of-the-art machine learning models have been explored and used to solve problems that were never fully addressed in the past. In this paper, the most recent results of application of machine learning and numerical optimisation for injection, extraction and transfer of beam from machine and to experimental areas are presented. An overview of the possible next steps and shortcomings is finally discussed.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOST045  
About • Received ※ 06 June 2022 — Revised ※ 14 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 10 July 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPOST049 Simulation Study for an Inverse Designed Narrowband THz Radiator for Ultrarelativistic Electrons radiation, simulation, electron, photon 973
 
  • G. Yadav, C.P. Welsch
    The University of Liverpool, Liverpool, United Kingdom
  • T. Feurer
    Universität Bern, Institute of Applied Physics, Bern, Switzerland
  • U. Haeusler, A. Kirchner
    FAU, Erlangen, Germany
  • B. Hermann, R. Ischebeck
    PSI, Villigen PSI, Switzerland
  • P. Hommelhoff
    University of Erlangen-Nuremberg, Erlangen, Germany
  • C.P. Welsch
    Cockcroft Institute, Warrington, Cheshire, United Kingdom
 
  THz radiation has many applications, including medical physics, pump-probe experiments, communications, and security systems. Dielectric grating structures can be used to generate cost-effective and beam synchronous THz radiation based on the Smith Purcell effect. We present a 3-D finite difference time domain (FDTD) simulation study for the THz radiation emitted from an inverse designed grating structure after a 3 GeV electron bunch traverses through it. Our farfield simulation results show a narrowband emission spectrum centred around 881 um, close to the designed value of 900 um. The grating structure was experimentally tested at the SwissFEL facility, and our simulated spectrum shows good agreement with the observed one.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOST049  
About • Received ※ 08 June 2022 — Revised ※ 10 June 2022 — Accepted ※ 11 June 2022 — Issue date ※ 12 June 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPOST050 Liverpool Centre for Doctoral Training for Innovation in Data Intensive Science cathode, simulation, electron, network 976
 
  • C.P. Welsch
    Cockcroft Institute, Warrington, Cheshire, United Kingdom
  • C.P. Welsch
    The University of Liverpool, Liverpool, United Kingdom
 
  Funding: This new Center for Doctoral Training has received funding from the UK’s Science and Technology Facilities Council.
The Liverpool center for doctoral training for innovation in data intensive science (LIV. INNO) is an inclusive hub for training three cohorts of students in data intensive science. Starting in October 2022, each year will train about 12 PhD students in applying data skills to address cutting edge research challenges across astrophysics, nuclear, theoretical and particle physics, as well as accelerator science. This framework is expected to provide an ideal basis for driving science and innovation, as well as boosting the employability of the LIV. INNO PhD students. This contribution gives examples of the accelerator science R&D projects in the center. It includes details about research into the optimization of 3D imaging techniques and the characterization of photocathodes for accelerator applications.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOST050  
About • Received ※ 05 June 2022 — Revised ※ 09 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 06 July 2022
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TUPOST051 Using Data Intensive Science for Accelerator Optimization plasma, simulation, electron, radiation 980
 
  • C.P. Welsch
    Cockcroft Institute, Warrington, Cheshire, United Kingdom
  • C.P. Welsch
    The University of Liverpool, Liverpool, United Kingdom
 
  Funding: This work was supported by STFC under grant agreement ST/P006752/1.
Particle accelerators and light sources are some of the largest, most data intensive, and most complex scientific systems. The connections and relations between machine subsystems are complicated and often nonlinear with system dynamics involving large parameter spaces that evolve over multiple relevant time scales and accelerator systems. In 2017, the Liverpool Centre for Doctoral Training in Data Intensive Science (LIV. DAT) was established. With almost 40 PhD students, the centre is now established as an international hub for training PhD students in data intensive science. This contribution presents results from studies carried out in LIV. DAT into novel high gradient accelerators with a focus on the data science techniques that were used. This includes studies into inverse-designed narrowband THz radiators for ultra-relativistic electrons, simulation of the transverse asymmetry and inhomogeneity on seeded self-modulation of beams in plasma, as well as studies into the physical aspects of collinear laser injection in Trojan Horse laser plasma experiments.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOST051  
About • Received ※ 08 June 2022 — Revised ※ 09 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 05 July 2022
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TUPOST054 Experiment of Bayesian Optimization for Trajectory Alignment at Low Energy RHIC Electron Cooler electron, alignment, collider, controls 987
 
  • Y. Gao, K.A. Brown, X. Gu, J. Morris, S. Seletskiy
    BNL, Upton, New York, USA
  • J.A. Crittenden, G.H. Hoffstaetter, W. Lin
    Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
 
  Funding: Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy; U.S. National Science Foundation under Award PHY-1549132, the Center for Bright Beams.
As the world’s first electron cooler that uses radio frequency (rf) accelerated electron bunches, the low energy RHIC electron cooling (LEReC) system is a nonmagnetized cooler of ion beams in RHIC at Brookhaven National Laboratory. Beam dynamics in LEReC are different from the more conventional electron coolers due to the bunching of the electron beam. To ensure an efficient cooling performance at LEReC, many parameters need to be monitored and fine-tuned. The alignment of the electron and ion trajectories in the LEReC cooling sections is one of the most critical parameters. This work explores using a machine learning (ML) method - Bayesian Optimization (BO) to optimize the trajectories’ alignment. Experimental results demonstrate that ML methods such as BO can perform control tasks efficiently in the RHIC controls system.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOST054  
About • Received ※ 04 June 2022 — Revised ※ 11 June 2022 — Accepted ※ 13 June 2022 — Issue date ※ 27 June 2022
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TUPOST059 PyEmittance: A General Python Package for Particle Beam Emittance Measurements with Adaptive Quadrupole Scans emittance, quadrupole, software, simulation 1003
 
  • S.A. Miskovich, A.L. Edelen, C.E. Mayes
    SLAC, Menlo Park, California, USA
 
  The emittance of a particle beam is a critically important parameter for many particle accelerator applications. Its measurements guide the initial tuning of an accelerator and are typically done using quadrupole or wire scans. Quadrupole scans are time-intensive, and it can be difficult to determine scan values that provide a good emittance measurement. To address this issue, we describe an adaptive quadrupole scan method that automates the determination of the scan range. With a given initial set of scanning values, our method adapts the range to capture the waist of the beam, and returns the Twiss parameters and a measure of the beam matching at the measurement screen. With the added capability to repeat beam size measurements when needed, this method provides a reliable measurement of the emittance even with sub-optimal initial conditions. To efficiently integrate these measurements into Python-based machine learning optimizations, the method was developed into a Python package, PyEmittance, at the SLAC National Accelerator Laboratory. We present the experimental tests of PyEmittance as performed at the Linac Coherent Light Source (LCLS) and the Facility for Advanced Accelerator Experimental Test (FACET-II).  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOST059  
About • Received ※ 08 June 2022 — Revised ※ 13 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 17 June 2022
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TUPOPT005 Status of the Superconducting Soft X-Ray Free-Electron Laser User Facility FLASH laser, undulator, FEL, operation 1006
 
  • M. Vogt, C. Gerth, K. Honkavaara, M. Kuhlmann, J. Rönsch-Schulenburg, L. Schaper, S. Schreiber, R. Treusch, J. Zemella
    DESY, Hamburg, Germany
 
  The XUV and soft X-ray free-electron laser FLASH at DESY is capable of operating two undulator beamlines simultaneously with up to several thousand bunches per second. It is driven by a normal conducting RF photo-cathode gun and a superconducting L-band linac. FLASH is currently undergoing a substantial refurbishment and upgrade program (FLASH2020+). The first 9-months installation shutdown started in November 2021. Here we report on the operation in 2021 and present main upgrades during the ongoing shutdown.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOPT005  
About • Received ※ 07 June 2022 — Revised ※ 13 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 17 June 2022
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TUPOPT008 An Overview of the T20 Beamline for the LUXE Experiment at the European XFEL FEL, emittance, electron, linac 1014
 
  • S.D. Walker, N. Golubeva
    DESY, Hamburg, Germany
 
  The Laser Und XFEL Experiment (LUXE) at the EUXFEL aims to explore hitherto unprobed regions of quantum electrodynamics characterised by both high-energy and high-intensity. This will be accomplished by leveraging the electron beam provided by the EUXFEL and an intensely-focussed laser to study electron-photon and photon-photon interactions. The LUXE experiment will be placed in the empty XTD20 tunnel and to this end a new beamline, T20, will need to be installed to deliver one bunch per bunch train to LUXE. The T20 beamline feature a total bend angle of 6.7 degrees, which combined with the very short bunches provided by the EUXFEL raises concerns regarding the deleterious impact of of coherent synchrotron radiation (CSR) on the bunch emittances. As the LUXE experiment has specific beam size requirements at its IP, these effects and the limits on the focus must be characterised. In this paper the T20 beamline design and its final focus are outlined. Furthermore, the impact of collective effects on the beam quality at the LUXE IP are discussed, and finally a means to mitigate the impact of these effects and improve the beam quality at the LUXE IP is shown.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOPT008  
About • Received ※ 13 June 2022 — Revised ※ 14 June 2022 — Accepted ※ 19 June 2022 — Issue date ※ 10 July 2022
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TUPOPT016 Status of the THz@PITZ Project - The Proof-of-Principle Experiment on a THz SASE FEL at the PITZ Facility undulator, FEL, electron, dipole 1033
 
  • T. Weilbach, P. Boonpornprasert, G.Z. Georgiev, G. Koss, M. Krasilnikov, X.-K. Li, A. Lueangaramwong, F. Mueller, A. Oppelt, S. Philipp, F. Stephan
    DESY Zeuthen, Zeuthen, Germany
 
  Funding: This work was supported by the European XFEL research and development program.
In order to allow THz pump/X-ray probe experiments at full bunch repetition rate for users at the European XFEL, the Photo Injector Test Facility at DESYin Zeuthen (PITZ) is building a prototype of an accelerator-based THz source. The goal is to generate THz SASE FEL radiation with a mJ energy level per bunch using an undulator driven by the electron beam from PITZ. Therefore, the existing PITZ beam line is extended into a tunnel annex downstream of the existing accelerator tunnel. The final design of the beam line extension consists of a bunch compressor, a collimation system and a beam dump in the PITZ tunnel. In the tunnel annex one LCLS-I undulator is installed for the production of the THz radiation with a quadrupole triplet in front of it for matching the beam parameters for the FEL process. Behind the undulator two screen stations couple out the THz radiation, for measurements of bunch compression, pulse energy or spatial distribution. A dipole separates the electron from the THz beam and a quadrupole doublet transports the electron beam to the beam dump. The installation progress will be presented.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOPT016  
About • Received ※ 07 June 2022 — Revised ※ 15 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 25 June 2022
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TUPOPT017 Start-to-end Simulations for Bunch Compressor and THz SASE FEL at PITZ FEL, simulation, booster, undulator 1037
 
  • A. Lueangaramwong, P. Boonpornprasert, M. Krasilnikov, X.-K. Li, F. Stephan
    DESY Zeuthen, Zeuthen, Germany
 
  The magnetic bunch compressor was designed as part of a THz accelerator source being developed at the Photo Injector Test facility at DESY in Zeuthen (PITZ) as a prototype for pump-probe experiments at the European XFEL. As an electron bunch is compressed to achieve higher bunch currents for the THz source, the beam dynamics in the bunch compressor was studied by numerical simulations. A start-to-end simulation optimizer including coherent synchrotron radiation (CSR) effects has been developed by combining the use of ASTRA, OCELOT, and GENESIS to support the design of the THz source prototype. In this paper we present simulation results to explore the possibility of improving the performance of the THz FEL at PITZ by using the developed bunch compressor.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOPT017  
About • Received ※ 18 May 2022 — Revised ※ 11 June 2022 — Accepted ※ 13 June 2022 — Issue date ※ 13 June 2022
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TUPOPT029 Infrared Free-Electron Laser Project in Thailand electron, FEL, radiation, FEM 1070
 
  • S. Rimjaem, N. Chaisueb, P. Kitisri, K. Kongmali, E. Kongmon, P. Nanthanasit, S. Pakluea, J. Saisut, S. Sukara, K. Techakaew, C. Thongbai
    Chiang Mai University, Chiang Mai, Thailand
  • P. Apiwattanakul, P. Jaikaew, W. Jaikla, N. Kangrang
    Chiang Mai University, PBP Research Facility, Chiang Mai, Thailand
  • M. Jitvisate
    Suranaree University of Technology, Nakhon Ratchasima, Thailand
  • M.W. Rhodes
    ThEP Center, Commission on Higher Education, Bangkok, Thailand
 
  The infrared free-electron laser (IR FEL) project is established at Chiang Mai University in Thailand with the aim to provide experimental stations for users utilizing accelerator-based terahertz (THz) and mid-infrared (MIR) radiation. Main components of the system include a thermionic RF gun, an alpha magnet as a bunch compressor and energy filter, a standing-wave RF linac, a THz transition radiation (THz-TR) station, two magnetic bunch compressors and beamlines for MIR/THz FEL. The system commissioning is ongoing to produce the beams with proper properties. Simulation results suggest that the oscillator MIR-FEL with wavelengths of 9.5-16.6 um and pulse energies of 0.15-0.4 uJ can be produced from 60-pC electron bunches with energy of 20-25 MeV. The super-radiant THz-FEL with frequencies of 1-3 THz and 700 kW peak power can be produced from 10-16 MeV electron bunches with a charge of 50 pC and a length of 200-300 fs. Furthermore, the THz-TR with a spectral range of 0.3-2.5 THz and a pulse power of up to 1.5 MW can be obtained. The MIR/THz FEL will be used as high-brightness light source for pump-probe experiments, while the coherent THz-TR will be used in time-domain spectroscopy.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOPT029  
About • Received ※ 08 June 2022 — Revised ※ 12 June 2022 — Accepted ※ 13 June 2022 — Issue date ※ 16 June 2022
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TUPOPT037 LCLS Multi-Bunch Improvement Plan: First Results kicker, FEL, linac, undulator 1092
 
  • A. Halavanau, A.L. Benwell, T.G. Beukers, L.B. Borzenets, F.-J. Decker, J. Hugyik, A. Ibrahimov, E.N. Jongewaard, A.K. Krasnykh, A.L. Le, K. Luchini, A.A. Lutman, A. Marinelli, M. Petree, A. Romero, A.V. Sy
    SLAC, Menlo Park, California, USA
 
  LCLS copper linac primarily operates in a single bunch mode with a repetition rate of 120 Hz. Presently, several in-house projects and LCLS user experiments require double- and multi-pulse trains of X-rays, with inter-pulse delay spanning between 0.35 and 220 ns. We discuss beam control improvements to the copper linac using ultra-fast stripline kicker, as well as additional photon diagnostics. We especially focus on a case of double-pulse mode, with 218 ns separation.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOPT037  
About • Received ※ 12 June 2022 — Revised ※ 13 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 10 July 2022
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TUPOPT038 FAST-GREENS: A High Efficiency Free Electron Laser Driven by Superconducting RF Accelerator undulator, electron, laser, radiation 1094
 
  • P. Musumeci, P.E. Denham, A.C. Fisher, Y. Park
    UCLA, Los Angeles, California, USA
  • R.B. Agustsson, T.J. Hodgetts, A.Y. Murokh, M. Ruelas
    RadiaBeam, Santa Monica, California, USA
  • L. Amoudry
    Université Paris-Saclay, CNRS/IN2P3, IJCLab, Orsay, France
  • D.R. Broemmelsiek, S. Nagaitsev, J. Ruan, J.K. Santucci, G. Stancari, A. Valishev
    Fermilab, Batavia, Illinois, USA
  • D.L. Bruhwiler, J.P. Edelen, C.C. Hall
    RadiaSoft LLC, Boulder, Colorado, USA
  • A.H. Lumpkin, A. Zholents
    ANL, Lemont, Illinois, USA
 
  Funding: This work is supported by DOE grants DE-SC0017102, DE-SC0018559 and DE-SC0009914
In this paper we’ll describe the FAST-GREENS experimental program where a 4 m-long strongly tapered helical undulator with a seeded prebuncher is used in the high gain TESSA regime to convert a significant fraction (up to 10 %) of energy from the 240 MeV electron beam from the FAST linac to coherent 515 nm radiation. We’ll also discuss the longer term plans for the setup where by embedding the undulator in an optical cavity matched with the high repetition rate from the superconducting accelerator (3,9 MHz), a very high average power laser source can be obtained. Eventually, the laser pulses can be redirected onto the relativistic electrons to generate by inverse compton scattering a very high flux of circularly polarized gamma rays for polarized positron production.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOPT038  
About • Received ※ 09 June 2022 — Revised ※ 12 June 2022 — Accepted ※ 12 June 2022 — Issue date ※ 02 July 2022
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TUPOPT044 High-Power Attosecond Pulses via Cascaded Amplification electron, FEM, laser, ISOL 1101
 
  • P.L. Franz, Z.H. Guo, S. Li, R. Robles
    Stanford University, Stanford, California, USA
  • D.K. Bohler, D.B. Cesar, X. Cheng, J.P. Cryan, T.D.C. Driver, J.P. Duris, A. Kamalov, S. Li, A. Marinelli, R. Obaid, R. Robles, N.S. Sudar, A.L. Wang, Z. Zhang
    SLAC, Menlo Park, California, USA
 
  Funding: This work was supported by US Department of Energy Contracts No. DE-AC02-76SF00.
The timescale for electron motion in molecular systems is on the order of hundreds of attoseconds, and thus the time-resolved study of electronic dynamics requires a source of sub-femtosecond x-ray pulses. Here we report the experimental generation of sub-femtosecond duration soft x-ray free electron laser (XFEL) pulses with hundreds of microjoules of energy using fresh-slice amplification in two cascaded stages at the Linac Coherent Light Source. In the first stage, an enhanced self-amplified spontaneous emission (ESASE) pulse is generated using laser-shaping of the electron beam at the photocathode*. The electron bunch is then delayed relative to the pulse by a magnetic chicane, allowing the radiation to slip onto a fresh slice of the bunch, which amplifies the ESASE pulse in the second cascade stage. Angular streaking** characterizes the experimental pulse durations as sub-femtosecond at ~465 eV in the experiment.
* Zhang, Z. et al. New J. Phys. 22 (2020)
** Li, S. et al. Optics Express 26.4 (2018): 4531-4547.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOPT044  
About • Received ※ 08 June 2022 — Revised ※ 15 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 21 June 2022
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TUPOPT047 Progress Report on Population Inversion X-Ray Laser Oscillator at LCLS cavity, laser, target, FEL 1107
 
  • A. Halavanau, R. Alonso-Mori, A. Aquila, U. Bergmann, F.-J. Decker, F. Fuller, M. Liang, A.A. Lutman, R.A. Margraf, R.H. Paul, C. Pellegrini
    SLAC, Menlo Park, California, USA
  • R. Ash, N.B. Welke
    UW-Madison/PD, Madison, Wisconsin, USA
  • A.I. Benediktovitch
    DESY, Hamburg, Germany
  • S.C. Krusic
    JSI, Ljubljana, Slovenia
  • N. Majernik, P. Manwani, J.B. Rosenzweig
    UCLA, Los Angeles, California, USA
  • R. Robles
    Stanford University, Stanford, California, USA
  • N. Rohringer
    Max Planck Institute for the Physics of Complex Systems, Dresden, Germany
 
  We report the progress in the design and construction of a population inversion x-ray laser oscillator (XLO) using LCLS as an x-ray laser pump, being developed by a SLAC, CFEL, University of Hamburg (Germany), University of Wisconsin, Josef Stefan Institute (Slovenia) and UCLA collaboration. In this proceeding, we will present the latest XLO design and numerical simulations substantiated by our first experimental results. In our next experimental step XLO will be tested on the Coherent X-ray Imaging (CXI) end-station at LCLS as a two pass Regenerative Amplifier operating at the Copper Kα1 photon energy of 8048 eV. When built, XLO will generate fully coherent transform limited pulses with about 50 meV FWHM bandwidth. We expect the XLO will pave the way for new user experiments, e.g. in inelastic x-ray scattering, parametric down conversion, quantum science, x-ray interferometry, and external hard x-ray XFEL seeding.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOPT047  
About • Received ※ 12 June 2022 — Revised ※ 14 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 24 June 2022
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TUPOPT048 bERLinPro Becomes SEALab: Status and Perspective of the Energy Recovery Linac at HZB linac, SRF, electron, cavity 1110
 
  • A. Neumann, B. Alberdi-Esuain, T. Birke, P. Echevarria, D. Eichel, F. Falkenstern, R. Fleischhauer, A. Frahm, F. Göbel, A. Heugel, F. Hoffmann, H. Huck, T. Kamps, S. Klauke, G. Klemz, J. Kolbe, J. Kühn, B.C. Kuske, J. Kuszynski, S. Mistry, N. Ohm, H. Ploetz, S. Rotterdam, O. Schappeit, G. Schindhelm, C. Schröder, M. Schuster, H. Stein, E. Suljoti, Y. Tamashevich, M. Tannert, J. Ullrich, A. Ushakov, J. Völker, C. Wang
    HZB, Berlin, Germany
  • T. Kamps
    HU Berlin, Berlin, Germany
 
  Funding: Work supported by German Bundesministerium für Bildung und Forschung, Land Berlin, and grants of Helmholtz Association
Since end of the year 2020 the energy recovery linac (ERL) project bERLinPro of Helmholtz-Zentrum Berlin has been officially completed. But what is the status of this facility, the next scientific goals in the framework of accelerator physics at HZB, what are the perspectives? To reflect the continuation of this endeavor and the broadening of applications of this machine from high current SRF based energy recovery concept up to an ultrafast electron diffraction (UED) facility producing shortest electron pulses, the facility is now named Sealab, Superconducting RF Electron Accelerator Laboratory. In this contribution, an overview of lessons learned so far, the status of the machine, the coming set up and commissioning steps with an outlook to midterm and future applications will be given. In summary, Sealab will expand, including the ERL application, and become a general accelerator physics and technology test machine to employ UED as a first study case and will also be an ideal testbed to investigate new control schemes based on digital twins or machine learning methods.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOPT048  
About • Received ※ 06 June 2022 — Revised ※ 13 June 2022 — Accepted ※ 14 June 2022 — Issue date ※ 03 July 2022
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TUPOPT053 Study of Bunch Length Measurement by Forward Coherent Smith-Purcell Radiation radiation, electron, background, detector 1125
 
  • H. Yamada, H. Hama, F. Hinode, K. Kanomata, S. Kashiwagi, S. Miura, T. Muto, I. Nagasawa, K. Nanbu, H. Saito, K. Shibata, K. Takahashi
    Tohoku University, Research Center for Electron Photon Science, Sendai, Japan
 
  We are currently conducting basic research on the development of a non-destructive real-time bunch length monitor using coherent Smith-Purcell radiation at the t-ACTS test accelerator at the Center for Electron Photon Science, Tohoku University. The angular distribution of coherent Smith-Purcell radiation reflects the longitudinal shape of the electron bunch. Using this, we came up with a method to measure the bunch length from the peak angle of the angular distribution. In this presentation, we mainly report the results of an experiment to determine the bunch length from the peak angle of the angular distribution of coherent Smith-Purcell radiation using a 100 fs electron beam of t-ACTS.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOPT053  
About • Received ※ 14 June 2022 — Revised ※ 15 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 09 July 2022
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TUPOPT054 Generation of Coherent THz Transition Radiation for Time Domain Spectroscopy at the PBP-CMU Electron Linac Laboratory radiation, electron, linac, FEM 1129
 
  • S. Pakluea
    Chiang Mai University, PBP Research Facility, Chiang Mai, Thailand
  • M. Jitvisate
    Suranaree University of Technology, Nakhon Ratchasima, Thailand
  • S. Rimjaem, J. Saisut, C. Thongbai
    Chiang Mai University, Chiang Mai, Thailand
  • S. Rimjaem, J. Saisut, C. Thongbai
    ThEP Center, Commission on Higher Education, Bangkok, Thailand
 
  The accelerator system at the PBP-CMU Electron Linac Laboratory is used to generate terahertz transition radiation (THz-TR). Due to broad spectrum, it can be used as the light source for THz time-domain spectroscopy (TDS) to measure both the intensity and phase of the THz signal. This contribution presents the generation of the THz-TR produced from 10-20 MeV electron beams and the system preparation for THz TDS. The electron bunches, which are compressed to have a length of femtosecond scale at the experimental station, is used to generate the THz-TR using a 45°-tilted aluminum foil as a radiator. The radiation properties including angular distribution, polarization and radiation spectrum are measured in the accelerator hall and at the TDS station. The radiation spectral range covers up to 2.3 THz with the peak power of 0.5 - 1.25 MW is expected. The effects of electron bunch distribution, divergence of the beam and influence of optical components on the radiation properties were studied. The results show that the considered effects have a significant impact on the TR properties. The Information will be used in the TR characterization that is needed to be interpreted carefully.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOPT054  
About • Received ※ 08 June 2022 — Revised ※ 14 June 2022 — Accepted ※ 27 June 2022 — Issue date ※ 04 July 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPOPT059 Machine Learning Methods for Chromaticity Control at the 1.5 GeV Synchrotron Light Source DELTA sextupole, storage-ring, synchrotron, controls 1141
 
  • D. Schirmer, A. Althaus, T. Schüngel
    DELTA, Dortmund, Germany
 
  In the past, the chromaticity values at the DELTA electron storage ring were manually adjusted using 15 individual sextupole power supply circuits, which are combined into 7 magnet families. To automate and optimize the time-consuming setting process, various machine learning (ML) approaches were investigated. For this purpose, simulations were first performed using a storage ring model and the performance of different neural network (NN) based models was compared. Subsequently, the neural networks were trained with experimental data and successfully implemented for chromaticity correction in real accelerator operation.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOPT059  
About • Received ※ 20 May 2022 — Revised ※ 11 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 21 June 2022
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TUPOPT062 A Data-Driven Anomaly Detection on SRF Cavities at the European XFEL cavity, FEL, network, SRF 1152
 
  • A. Sulc, A. Eichler, T. Wilksen
    DESY, Hamburg, Germany
 
  Funding: This work was supported by HamburgX grant LFF-HHX-03 to the Center for Data and Computing in Natural Sciences (CDCS) from the Hamburg Ministry of Science, Research, Equalities and Districts.
The European XFEL is currently operating with hundreds of superconducting radio frequency cavities. To be able to minimize the downtimes, prevention of failures on the SRF cavities is crucial. In this paper, we propose an anomaly detection approach based on a neural network model to predict occurrences of breakdowns on the SRF cavities based on a model trained on historical data. We used our existing anomaly detection infrastructure to get a subset of the stored data labeled as faulty. We experimented with different training losses to maximally profit from the available data and trained a recurrent neural network that can predict a failure from a series of pulses. The proposed model is using a tailored architecture with recurrent neural units and takes into account the sequential nature of the problem which can generalize and predict a variety of failures that we have been experiencing in operation.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOPT062  
About • Received ※ 17 May 2022 — Revised ※ 14 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 24 June 2022
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TUPOPT069 Preparation and Characterization of BTO-BFO Multiferroic Ceramics as Electrical Controllable Fast Phase Shifting Component controls, factory, site, radiation 1178
 
  • N.W. Martirosyan, A. Grigoryan, Kh.Gh. Kirakosyan, V. Sahakyan, A. Sargsyan
    CANDLE SRI, Yerevan, Armenia
  • A. Grigoryan
    YSU, Yerevan, Armenia
  • G.S. Karoyan, R.H. Khazaryan, M.M. Mkrtchian, T. Vandunts
    NPUA, Yerevan, Armenia
 
  A rich variety of dielectric, optical, acoustic/piezoelectric, ferromagnetic properties of ferroelectric and multiferroic composite materials open a new perspective for the development of modern accelerators with new principle of electron acceleration and control system. These properties may be controlled by external electric fields. In particular, the production of electric field controlling ultrafast facilities for 0.7-20 GHz RF phase shifting and amplitude modulation where a very short response time of <10 nsec is required . A Self-propagating High-temperature Synthesis (SHS) technology for obtaining ceramic materials, based on (1-x)BiFeO3-xBaTiO3 compositions with various dopant (MgO, MnO, etc.), has been developed. The general parameters of the SHS process (temperature and propagation velocity of the combustion front) are measured. The dependences of microstructure (grain size, density, and porosity), as well as electro physical properties of the sintered samples on compaction and sintering thermodynamic variables, such as the pressing pressure and duration, sintering temperature, sintering duration and atmosphere, heating and cooling rates, are experimentally investigated.
* https://doi.org/10.3390/coatings11010066
** Appl. Phys. Let., V.101, p. 232903-5, 2012
*** A. Kanareykin & et al. FERROELECTRIC BASED HIGH POWER TUNER FOR L-BAND ACCELERATOR APPLICATIONS. IPAC2013
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOPT069  
About • Received ※ 31 May 2022 — Revised ※ 11 June 2022 — Accepted ※ 11 June 2022 — Issue date ※ 12 June 2022
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TUPOTK006 Systematic Investigation of Flux Trapping Dynamics in Niobium Samples cavity, SRF, controls, niobium 1200
 
  • F. Kramer, S. Keckert, S. Keckert, J. Knobloch, J. Knobloch, O. Kugeler
    HZB, Berlin, Germany
  • J. Knobloch, O. Kugeler
    BESSY GmbH, Berlin, Germany
  • J. Knobloch
    University of Siegen, Siegen, Germany
 
  Trapped magnetic flux in superconducting cavities can significantly increase surface resistance, and, thereby, limits the cavities’ performance. To reduce trapped flux in cavities, a better understanding of the fundamental mechanism of flux trapping is vital. We develop a new experimental design: measuring magnetic flux density at 15 points just above a niobium sheet of dimensions (100 x 60 x 3) mm with a time resolution of up to 2 ms and a flux resolution better than 0.5 µT. This setup allows us to control the temperature gradient and cooldown rate, both independently of each other, as well as the magnitude and direction of an external magnetic field. We present data gathered on a large-grain sample as well as on a fine-grain sample. Our data suggests that not only the temperature gradient but also the cooldown rate affects trapped flux. Additionally, we detect a non-trivial relationship between trapped flux and magnitude of applied field.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOTK006  
About • Received ※ 08 June 2022 — Revised ※ 12 June 2022 — Accepted ※ 13 June 2022 — Issue date ※ 16 June 2022
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TUPOTK020 Status of LASA-INFN R&D Activity on PIP-II Low-beta Prototypes cavity, radiation, SRF, operation 1241
 
  • M. Bertucci, A. Bosotti, A. D’Ambros, E. Del Core, A.T. Grimaldi, P. Michelato, L. Monaco, C. Pagani, R. Paparella, D. Sertore
    INFN/LASA, Segrate (MI), Italy
  • A. Gresele
    Zanon Research & Innovation, Schio, VI, Italy
  • C. Pagani
    Università degli Studi di Milano & INFN, Segrate, Italy
 
  LASA-INFN is developing some PIP-II β=0.61 cavity prototypes so to set up a high-Q recipe allowing to reach the PIP-II performance target in view of the series production. A single-cell cavity was treated with a XFEL-like baseline recipe, whereas a multicell cavity underwent a mid-T bake step as final surface treatment. Both cavities have been then tested at the LASA vertical experimental facility. The test results are here reported and discussed. Basing on the satisfactory results so far obtained, a strategy for the qualification and upgrade of the LASA vertical test facility is outlined.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOTK020  
About • Received ※ 08 June 2022 — Revised ※ 13 June 2022 — Accepted ※ 14 June 2022 — Issue date ※ 16 June 2022
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TUPOTK023 Study on Commercial Diodes as Thermometers at Low Temperature for Temperature Mapping System of Nb3sn Superconducting Radiofrequency Cavities cavity, SRF, laser, controls 1252
 
  • R. Wanison, K. Umemori, T. Yamada
    KEK, Ibaraki, Japan
  • K. Takahashi
    Sokendai, Ibaraki, Japan
  • R. Wanison
    Department of Mechanical Engineering, Faculty of Engineering, Chiang Mai University, Chiang Mai, Thailand
 
  Nb3Sn Superconducting radiofrequency (SRF) cavities has been researched and developed at Center for Applied Superconducting Accelerator (CASA), KEK. One of effec-tive tools for research on the performance of SRF cavities is a temperature mapping (T-map) system for detecting small increases in temperature. It is a thermometer array positioned precisely on an outer surface of cavity wall. Thermometer should cover at least from the range of typi-cal operating temperature of 4 K to the transition tempera-ture of 18 K, for the Nb3Sn SRF cavities. Therefore, car-bon resistor can not be used as a cheap thermometer due to low sensitivity at this temperature range. In this pro-ceeding, we report the results of the test for various com-mercially available diodes as a thermometer for T-map system. The sensitivity, stability and the repeatability are measured, cooled by a GM cryocooler.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOTK023  
About • Received ※ 08 June 2022 — Revised ※ 11 June 2022 — Accepted ※ 13 June 2022 — Issue date ※ 07 July 2022
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TUPOMS015 Proposal of a Girder Realignment Test in PETRA III alignment, controls, storage-ring, vacuum 1435
 
  • M. Schaumann, I.V. Agapov, R. Bartolini, M. Bieler, R. Böspflug, D. Einfeld, M.G. Hoffmann, J. Keil, L. Liao, G. Priebe, M. Schlösser, R. Wanzenberg
    DESY, Hamburg, Germany
 
  PETRA IV can benefit from the fine control of the girders that carry the storage ring elements to achieve the design beam performance. Based on the corrector magnet strength pattern it is desired to realign girders to stay within the alignment tolerances. In the current PETRA III configuration, the girders in the Max von Laue Hall are equipped for remote alignment, however, those have not been moved since their initial installation and the alignment system is currently not connected to the control system. In preparation for PETRA IV, a movement test of one of the PETRA III girders should confirm the ability to safely and precisely remote control the equipment based on an optics model that describes the effect of the girder movement on the orbit. This paper studies the feasibility of this test and prepares an initial mock-up experiment to be performed on a spare girder.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOMS015  
About • Received ※ 07 June 2022 — Revised ※ 13 June 2022 — Accepted ※ 14 June 2022 — Issue date ※ 15 June 2022
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TUPOMS020 Long-Term Orbit Stability in the PETRA III Storage Ring alignment, operation, storage-ring, status 1449
 
  • L. Liao, M. Bieler, J. Keil, C. Li, M. Schaumann, R. Wanzenberg
    DESY, Hamburg, Germany
 
  The study of long-term orbit stability in the PETRA III light source plays an important role for the design of its upgrade to PETRA IV. The PETRA III tunnel is made of individual segments that move against each other. Here, the long-term drifts of the tunnel ground that are mostly introduced by temperature variations, are of the highest concern for the PETRA IV alignment tolerances and orbit stability. This paper studies the evolution of the beam orbit and corrector magnet currents over several years and correlates tunnel movement to RMS orbit drifts.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOMS020  
About • Received ※ 16 May 2022 — Revised ※ 12 June 2022 — Accepted ※ 13 June 2022 — Issue date ※ 06 July 2022
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TUPOMS021 PETRA III Operational Performance and Availability operation, synchrotron, synchrotron-radiation, dipole 1453
 
  • R. Wanzenberg, M. Bieler, J. Keil, L. Liao, G.K. Sahoo, M. Schaumann
    DESY, Hamburg, Germany
 
  At DESY the Synchrotron Light Source PETRA III offers scientists outstanding opportunities for experiments with hard X-rays of exceptionally high brilliance since 2009. The light source is operated mainly in two operation modes with 480 and 40 bunches at a beam energy of 6 GeV. With the completion of the last milestone of the extension project in summer 2021 that brought the new dipole beamline P66 into operation, 2022 is the first year where almost 5000 hours of user run time could be scheduled. This paper will review the statistics of availability and failures over the years and provides a detailed description of the operation in 2021. Additionally, an outlook for the next runs is given.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOMS021  
About • Received ※ 19 May 2022 — Revised ※ 13 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 17 June 2022
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TUPOMS037 RCDS-S: An Optimization Method to Compensate Accelerator Performance Drifts kicker, simulation, operation, storage-ring 1506
 
  • Z. Zhang, X. Huang, M. Song
    SLAC, Menlo Park, California, USA
 
  We propose an optimization algorithm, Safe Robust Conjugate Direction Search (RCDS-S), which can perform accelerator tuning while keeping the machine performance within a designated safe envelope. The algorithm builds probability models of the objective function using Lipschitz continuity of the function as well as characteristics of the drifts and applies to the selection of trial solutions to ensure the machine operates safely during tuning. The algorithm can run during normal user operation constantly, or periodically, to compensate for the performance drifts. Simulation and online tests have been done to validate the performance of the algorithm.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOMS037  
About • Received ※ 08 June 2022 — Revised ※ 16 June 2022 — Accepted ※ 30 June 2022 — Issue date ※ 30 June 2022
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TUPOMS043 High Power Tests of a New 4-Rod RFQ with Focus on its Mechanical Vibrations simulation, rfq, laser, operation 1523
 
  • S.R. Wagner, D. Koser, K. Kümpel, H. Podlech
    IAP, Frankfurt am Main, Germany
  • K.B. Bahrke-Rein
    TU Darmstadt, Darmstadt, Germany
  • M. Basten
    GSI, Darmstadt, Germany
  • M. Basten
    HIM, Mainz, Germany
  • H. Podlech
    HFHF, Frankfurt am Main, Germany
 
  Because of strong mechanical vibrations of the electrodes and its sensitivity to changes of thermal load, the operational stability of the existing 4-rod RFQ at the High Charge State Injector (HLI) at the GSI Helmholtz Centre for Heavy Ion Research in Darmstadt, Germany, could not be ensured for all planned operating states. To resolve this issue and ensure stable injection into the HLI, a new RFQ-prototype, optimized in terms of vibration suppression and cooling efficiency, was designed at the Institute of Applied Physics (IAP) of Goethe University Frankfurt. To test the performance of this prototype and demonstrate the operational stability in terms of mechanical vibration as well as thermal load, high power tests with more than 25’kW/m were performed at GSI. After initial conditioning, detailed vibrational measurements during high power RF operation using a laser Doppler vibrometer were performed, which were then compared to previously conducted simulations using ANSYS. Ultimately, the ability for stable operation up to high power levels with an efficient vibration suppression and moderate heating have clearly been demonstrated.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOMS043  
About • Received ※ 07 June 2022 — Revised ※ 13 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 18 June 2022
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TUPOMS044 Dielectric Loaded THz Waveguide Experimentally Optimized by Dispersion Measurements GUI, electron, higher-order-mode, acceleration 1526
 
  • M.J. Kellermeier, R.W. Aßmann, K. Flöttmann, F. Lemery
    DESY, Hamburg, Germany
  • R.W. Aßmann
    LNF-INFN, Frascati, Italy
  • W. Hillert
    University of Hamburg, Institut für Experimentalphysik, Hamburg, Germany
 
  Emerging high power THz sources pave the road for THz- driven acceleration of ultra-short bunches, and enable their manipulation for diagnostic purposes. Due to the small feature sizes of THz-guiding devices new methods are necessary for their electromagnetic characterization. A new technique has recently been developed which characterizes THz waveguides with respect to their dispersion relations and attenuation. Here, the method is applied to circular waveguides, partially filled with polymer capillaries of different thicknesses, to find a suitable size for THz driven streaking at 287 GHz. Further, rough 3d-printed metallic waveguides are measured to study the effect of roughness on attenuation and phase constant. In general, additive manufacturing techniques show promise for advanced integrated designs of THz driven structures.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOMS044  
About • Received ※ 05 June 2022 — Revised ※ 12 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 28 June 2022
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TUPOMS046 Fabrication and Low-Power Test of Disk-and-Washer Cavity for Muon Acceleration cavity, linac, acceleration, dipole 1534
 
  • Y. Takeuchi, J. Tojo
    Kyushu University, Fukuoka, Japan
  • E. Cicek, H. Ego, K. Futatsukawa, N. Kawamura, T. Mibe, M. Otani, N. Saito, T. Yamazaki, M. Yoshida
    KEK, Ibaraki, Japan
  • Y. Iwashita
    Kyoto University, Research Reactor Institute, Osaka, Japan
  • R. Kitamura, T. Morishita
    JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
  • Y. Kondo
    JAEA, Ibaraki-ken, Japan
  • Y. Nakazawa
    Ibaraki University, Hitachi, Ibaraki, Japan
  • Y. Sue, K. Sumi, M. Yotsuzuka
    Nagoya University, Graduate School of Science, Chikusa-ku, Nagoya, Japan
  • H.Y. Yasuda
    University of Tokyo, Tokyo, Japan
 
  The muon g-2/EDM experiment is under preparation at Japan Proton Accelerator Research Complex (J-PARC), and the muon linear accelerator for the experiment is being developed. A Disk-and-Washer (DAW) cavity will be used for the medium-velocity part of the accelerator, and muons will be accelerated from v/c=ß=0.3 to 0.7 with the operating frequency of 1.296 GHz. Machining, brazing, and low-power measurements of a prototype cell reflecting the design of the first tank of DAW were performed to identify fabrication problems. Several problems were identified, such as displacement of washers during brazing, and some measures will be taken in the actual tank fabrication. In this paper, the results of the prototype cell fabrication will be reported.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOMS046  
About • Received ※ 08 June 2022 — Revised ※ 15 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 23 June 2022
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TUPOMS054 Data Augmentation for Breakdown Prediction in CLIC RF Cavities operation, cavity, network, ECR 1553
 
  • H.S. Bovbjerg, M. Shen, Z.H. Tan
    Aalborg University, Aalborg, Denmark
  • A. Apollonio, H.S. Bovbjerg, T. Cartier-Michaud, W.L. Millar, C. Obermair, D. Wollmann
    CERN, Meyrin, Switzerland
  • C. Obermair
    TUG, Graz, Austria
 
  One of the primary limitations on the achievable accelerating gradient in normal-conducting accelerator cavities is the occurrence of vacuum arcs, also known as RF breakdowns. A recent study on experimental data from the CLIC XBOX2 test stand at CERN proposes the use of supervised machine learning methods for predicting RF breakdowns. As RF breakdowns occur relatively infrequently during operation, the majority of the data was instead comprised of non-breakdown pulses. This phenomenon is known in the field of machine learning as class imbalance and is problematic for the training of the models. This paper proposes the use of data augmentation methods to generate synthetic data to counteract this problem. Different data augmentation methods like random transformations and pattern mixing are applied to the experimental data from the XBOX2 test stand, and their efficiency is compared.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOMS054  
About • Received ※ 08 June 2022 — Revised ※ 12 June 2022 — Accepted ※ 13 June 2022 — Issue date ※ 15 June 2022
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WEIXSP1 Towards High-Repetition Rate Petawatt Laser Experiments with Cryogenic Jets Using a Mechanical Chopper System laser, target, proton, plasma 1594
 
  • M. Rehwald, S. Assenbaum, C. Bernert, U. Schramm, K. Zeil
    HZDR, Dresden, Germany
  • C.B. Curry, M. Gauthier, S.H. Glenzer, C. Schoenwaelder, F. Treffert
    SLAC, Menlo Park, California, USA
  • S. Göde
    EuXFEL, Schenefeld, Germany
 
  Laser-plasma based ion accelerators require suitable high-repetition rate target systems that enable systematic studies at controlled plasma conditions and application-relevant particle flux. Self-refreshing, micrometer-sized cryogenic jets have proven to be an ideal target platform. Yet, operation of such systems in the harsh environmental conditions of high power laser induced plasma experiments have turned out to be challenging. Here we report on recent experiments deploying a cryogenic hydrogen jet as a source of pure proton beams generated with the PW-class ultrashort pulse laser DRACO. Damage to the jet target system during application of full energy laser shots was prevented by implementation of a mechanical chopper system interrupting the direct line of sight between the laser plasma interaction zone and the jet source.  
slides icon Slides WEIXSP1 [4.896 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEIXSP1  
About • Received ※ 16 May 2022 — Revised ※ 10 June 2022 — Accepted ※ 14 June 2022 — Issue date ※ 15 June 2022
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WEOYGD3 Isochronous Mode of the Experimental Storage Ring (ESR) at GSI sextupole, electron, detector, dipole 1620
 
  • S.A. Litvinov, R. Hess, B. Lorentz, M. Steck
    GSI, Darmstadt, Germany
 
  The isochronous optics of the ESR is a unique ion-optical setting in which the particles within a finite momentum acceptance circulate at constant frequency. It is used for direct mass measurements of short-lived exotic nuclei by a Time-of-Flight method. Besides the mass spectrometry, the isochronous ESR has been used as an instrument for the search of short lived isomers stored in the ring, which was performed in 2021 for the first time. Introduction to the isochronous mode of the ESR, comparison with a standard operational mode, recent machine experiments will be presented here. Possible improvements of the isochronous optics at the ESR and perspectives of the isochronous mode at CR, FAIR will be outlined.  
slides icon Slides WEOYGD3 [6.871 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEOYGD3  
About • Received ※ 08 June 2022 — Revised ※ 15 June 2022 — Accepted ※ 28 June 2022 — Issue date ※ 04 July 2022
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WEOZSP2 Suppression of Crab Cavity Noise Induced Emittance Growth by Transverse Beam Coupling Impedance emittance, impedance, simulation, octupole 1659
 
  • N. Triantafyllou, A. Wolski
    The University of Liverpool, Liverpool, United Kingdom
  • F. Antoniou, H. Bartosik, P. Baudrenghien, X. Buffat, R. Calaga, Y. Papaphilippou
    CERN, Meyrin, Switzerland
  • T. Mastoridis
    CalPoly, San Luis Obispo, California, USA
 
  Crab Cavities are a key component of the High Luminosity LHC (HL-LHC) upgrade, as they aim to minimize the luminosity reduction caused by the crossing angle. Two superconducting crab cavities were installed in the Super Proton Synchrotron (SPS) at CERN in 2018 to test their operation in a proton machine for the first time. An important point to consider is the increase in transverse emittance induced by noise in the Low-Level RF (LLRF) system. During the first experimental campaign in 2018, the measured emittance growth was found to be a factor of 4 lower than predicted by the available analytical models. In this report, the effects of transverse beam impedance in the presence of CC LLRF noise on transverse emittance growth are presented and the results of the second experimental campaign, which took place in the SPS in 2021, are discussed.  
slides icon Slides WEOZSP2 [2.694 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEOZSP2  
About • Received ※ 08 June 2022 — Revised ※ 12 June 2022 — Accepted ※ 14 June 2022 — Issue date ※ 15 June 2022
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WEPOST003 Implications of the Upgrade II of LHCb on the LHC Insertion Region 8: From Energy Deposition Studies to Mitigation Strategies luminosity, dipole, radiation, detector 1679
 
  • A. Ciccotelli
    The University of Manchester, Manchester, United Kingdom
  • R.B. Appleby
    UMAN, Manchester, United Kingdom
  • F. Butin, F. Cerutti, A. Ciccotelli, L.S. Esposito, B. Humann, M. Wehrle
    CERN, Meyrin, Switzerland
  • B. Humann
    TU Vienna, Wien, Austria
 
  Starting from LHC Run3, a first upgrade of the LHCb experiment (Upgrade I) will enable oeration with a significantly increased instantaneous luminosity in the LHC Insertion Region 8 (IR8), up to 2·1033/(cm2 s). Moreover, the proposed second upgrade of the LHCb experiment (Upgrade II) aims at increasing it by an extra factor 7.5 and collecting an integrated luminosity of 400/fb by the end of Run6. Such an ambitious goal poses challenges not only for the detector but also for the accelerator components. Monte Carlo simulations represent a valuable tool to predict the implications of the radiation impact on the machine, especially for future operational scenarios. A detailed IR8 model implemented by means of the FLUKA code is presented in this study. With such a model, we calculated the power density and dose distributions in the superconducting coils of the LHC final focusing quadrupoles (Q1-Q3) and separation dipole (D1) and we highlight a few critical issues calling for mitigation measures. Our study addresses also the recombination dipole (D2) and the suitability of the present TANb absorber, as well as the proton losses in the Dispersion Suppressor (DS) and their implications.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOST003  
About • Received ※ 08 June 2022 — Revised ※ 15 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 25 June 2022
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WEPOST023 Design of a Very Low Energy Beamline for NA61/SHINE target, optics, detector, radiation 1741
 
  • C.A. Mussolini, N. Charitonidis
    CERN, Meyrin, Switzerland
  • P. Burrows, C.A. Mussolini
    JAI, Oxford, United Kingdom
  • P. Burrows, C.A. Mussolini
    Oxford University, Physics Department, Oxford, Oxon, United Kingdom
  • Y. Nagai
    Colorado University at Boulder, Boulder, Colorado, USA
  • E.D. Zimmerman
    CIPS, Boulder, Colorado, USA
 
  A new, low-energy branch is being designed for the H2 beamline at the CERN North Experimental Area. This new low-energy branch would extend the capabilities of the current infrastructure enabling the study of particles in the low, 1 - 13 GeV/c, momentum range. The first experiment to profit from this new line will be NA61/SHINE (SPS Heavy Ion and Neutrino Experiment), a multi-purpose experiment studying hadron production in hadron-proton, hadron-nucleus and nucleus-nucleus collisions at the SPS. However, other future fixed target experiments or test-beam experiments installed in the downstream zones could also benefit from the low-energy particles provided. The proposed layout and expected performance of this line, along with estimates of particle rates, and considerations on the technical implementation of the beamline are presented in this contribution. A description on the instrumentation, which will enable particle-by-particle tagging, crucial for the experiments scope, is also discussed.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOST023  
About • Received ※ 08 June 2022 — Revised ※ 13 June 2022 — Accepted ※ 29 June 2022 — Issue date ※ 05 July 2022
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WEPOST024 Physics Beyond Colliders: The Conventional Beams Working Group proton, optics, kaon, target 1745
 
  • C.A. Mussolini, D. Banerjee, A. Baratto Roldan, J. Bernhard, M. Brugger, N. Charitonidis, G.L. D’Alessandro, L. Gatignon, A. Gerbershagen, F. Metzger, R.P. Murphy, E.G. Parozzi, S.M. Schuh-Erhard, F.W. Stummer, M.W.U. Van Dijk
    CERN, Meyrin, Switzerland
  • F. Metzger
    HISKP, Bonn, Germany
  • R.P. Murphy, F.W. Stummer
    Royal Holloway, University of London, Surrey, United Kingdom
  • C.A. Mussolini, F.W. Stummer
    JAI, Oxford, United Kingdom
  • C.A. Mussolini
    Oxford University, Physics Department, Oxford, Oxon, United Kingdom
  • E.G. Parozzi
    Universita Milano Bicocca, MILANO, Italy
  • E.G. Parozzi
    INFN MIB, MILANO, Italy
 
  The Physics Beyond Colliders initiative aims to exploit the full scientific potential of the CERN accelerator complex and its scientific infrastructure for particle physics studies, complementary to current and future collider experiments. Several experiments have been proposed to fully utilize and further advance the beam options for the existing fixed target experiments present in the North and East Experimental Areas of the CERN SPS and PS accelerators. We report on progress with the RF-separated beam option for the AMBER experiment, following a recent workshop on this topic. In addition we cover the status of studies for ion beams for the NA60+ experiment, as well as of those for high intensity beams for Kaon physics and feebly interacting particle searches. With first beams available in 2021 after a CERN-wide long shutdown, several muon beam options were already tested for the NA64mu, MUonE and AMBER experiments.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOST024  
About • Received ※ 08 June 2022 — Revised ※ 14 June 2022 — Accepted ※ 23 June 2022 — Issue date ※ 10 July 2022
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WEPOST039 Mapping Charge Capture and Acceleration in a Plasma Wakefield of a Proton Bunch Using Variable Emittance Electron Beam Injection electron, plasma, wakefield, emittance 1780
 
  • E. Granados, A.-M. Bachmann, E. Chevallay, S. Döbert, V.N. Fedosseev, F. Friebel, S.J. Gessner, E. Gschwendtner, S.Y. Kim, S. Mazzoni, M. Turner, L. Verra
    CERN, Meyrin, Switzerland
  • A.-M. Bachmann, L. Verra
    MPI, Muenchen, Germany
  • S.Y. Kim
    UNIST, Ulsan, Republic of Korea
  • S.Y. Kim
    ANL, Lemont, Illinois, USA
  • J.T. Moody
    MPI-P, München, Germany
 
  In the Phase 2 of the AWAKE first experimental run (from May to November 2018), an electron beam was used to probe and test proton-driven wakefield accelera-tion in a rubidium plasma column. The witness electron bunches were produced using an RF-gun equipped with a Cs2Te photocathode illuminated by a tailorable ultrafast ultraviolet (UV) laser pulse. The construction of the UV beam optical system enabled appropriate transverse beam shaping and control of its pulse duration, size, and position on the photocathode, as well as time delay with respect to the ionizing laser pulse that seeds the plasma wakefields in the proton bunches. Variable photocathode illumination provided the required flexibility to produce electron bunches with variable charge, emittance, and injection trajectory into the plasma column. In this work, we analyze the overall charge capture and shot-to-shot reproducibility of the proton-driven plasma wakefield accelerator with various UV illumination and electron bunch injection parameters.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOST039  
About • Received ※ 23 May 2022 — Revised ※ 10 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 29 June 2022
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WEPOST041 Physical Aspects of Collinear Laser Injection at SLAC FACET-II E-310: Trojan Horse Experiment plasma, radiation, laser, electron 1787
 
  • M. Yadav, O. Apsimon, E. Kukstas, C.P. Welsch
    The University of Liverpool, Liverpool, United Kingdom
  • C.E. Hansel, P. Manwani, B. Naranjo, J.B. Rosenzweig
    UCLA, Los Angeles, USA
  • B. Hidding
    USTRAT/SUPA, Glasgow, United Kingdom
 
  Funding: This work was performed with support of the US Department of Energy, Division of High Energy Physics, un-der Contract No. DE-SC0009914, and the STFC grant ST/P006752/1.
The Facility for Advanced Accelerator Experimental Tests (FACET-II) is a test accelerator infrastructure at SLAC dedicated to the research and development of advanced accelerator technologies. We performed simulations of electron beam driven wakefields, with collinear lasers used for ionization injection of electrons. We numerically generated a witness beam using the OSIRIS code in an up ramp plasma as well as uniform plasma regimes. We report on challenges and details of the E-310 experiment which aims to demonstrate this plasma photocathode injection at FACET-II. We examine the phenomena beam hosing and drive beam depletion. Details of the witness beam generated are discussed. Computation of betatron-radiation X-ray spatial distribution and critical energy are done for FACET-II low emittance beams.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOST041  
About • Received ※ 07 June 2022 — Revised ※ 14 June 2022 — Accepted ※ 21 June 2022 — Issue date ※ 23 June 2022
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WEPOST045 Simulating Enhanced Focusing Effects of Ion Motion in Adiabatic Plasmas plasma, focusing, emittance, electron 1798
 
  • D.R. Chow, C.E. Hansel, P. Manwani, J.B. Rosenzweig, M. Yadav
    UCLA, Los Angeles, USA
  • Ö. Apsimon, C.P. Welsch
    The University of Liverpool, Liverpool, United Kingdom
 
  Funding: This work was performed with support of the US Department of Energy, Division of High Energy Physics, under Contract No. DE-SC0009914, and the STFC Liverpool Centre for Doctoral Training on Data Intensive Science (LIV. DAT) under grant agreement ST/P006752/1.
The FACET-II facility offers the unique opportunity to study low emittance, GeV beams and their interactions with high density plasmas in plasma wakefield acceleration (PWFA) scenarios. One of the experiments relevant to PWFA research at FACET-II is the ion collapse experiment E-314, which aims to study how ion motion in a PWFA can produce dual-focused equilibrium. As nonlinear focusing effects due to nonuniform ion distributions have not been extensively studied; we explore the difficulties of inducing ion motion in an adiabatic plasma and examines the effect an ion column has on beam focusing. A case study is performed on a system containing a plasma lens and adiabatic PWFA. Ions in the lens section are assumed to be static, while simulations of an adiabatic matching section are modified to include the effects of ion column collapse and their nonlinear focusing fields. Using the parameters of the FACET-II beam, we find that a collapsed ion column amplifies the focusing power of a plasma without compromising emittance preservation. This led to a spot size orders of magnitude less than that of a simply matched beam.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOST045  
About • Received ※ 07 June 2022 — Revised ※ 15 June 2022 — Accepted ※ 23 June 2022 — Issue date ※ 25 June 2022
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WEPOST050 Further Measurements of Beam-Beam Interactions in a Gear-Changing System in DESIREE synchrotron, collider, pick-up, space-charge 1810
 
  • E.A. Nissen
    JLab, Newport News, Virginia, USA
  • A. Källberg, A. Simonsson
    Stockholm University, Stockholm, Sweden
 
  Funding: Notice: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177. The U.S. Government retains a license to publish or reproduce this manuscript.
In this work we detail experiments performed on a gear-changing system using the Double ElectroStatic Ion Ring ExpEriment (DESIREE). A gear-changing system is one where there are different harmonic numbers in each ring. This experiment used carbon and nitrogen beams in a 4 on 3 gear-changing arrangement, with the last bunch of each left off. The bunch length can be measured and synchrotron motion detected. We performed this measurement on three different values of carbon current, and present the differences in the bunch length frequency spectrum here, which correspond to twice the synchrotron frequencies.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOST050  
About • Received ※ 08 June 2022 — Revised ※ 11 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 30 June 2022
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WEPOST052 Influence of Plasma Electrode Aperture Size on Beam Emittance From a Multicusp Ion Source plasma, emittance, ion-source, extraction 1813
 
  • A.M. George, M.P. Dehnel, S.V. Melanson, J.J. Munich
    D-Pace, Nelson, British Columbia, Canada
  • N. Broderick
    University of Auckland, Auckland, New Zealand
 
  D-Pace’s TRIUMF-licensed multicusp filament ion source is capable of producing H beams up to 17.4 mA*. In most cases, the H beam is transported to the entrance of an accelerator or a magnet for further applications. The emittance of the beam extracted from the ion source should be maintained as low as possible to reduce the beam losses to the walls of the transport pipes. The beam emittance from the ion source can be controlled by changing the aperture diameter of the plasma electrode. The current study deals with the range of H beam emittance that can be achieved from D-Pace’s filament ion source, using different plasma electrode aperture sizes. The corresponding beam currents and the electron to ion ratios are also reported.
* Melanson, S., M. Dehnel, D. Potkins, H. McDonald, and C. Philpott. "H-, D-, C2-: a comparison of RF and filament powered volume-cusp ion sources." Ele 5 (2017): 10.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOST052  
About • Received ※ 06 June 2022 — Revised ※ 10 June 2022 — Accepted ※ 13 June 2022 — Issue date ※ 16 June 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPOST053 Extraction of High-Charge State Argon and α-Particles from D-Pace Penning Ion Source Test Stand ion-source, operation, extraction, cathode 1816
 
  • N. Savard
    UBC, Vancouver, B.C., Canada
  • M.P. Dehnel, J.J. Munich
    D-Pace, Nelson, British Columbia, Canada
 
  At D-Pace’s Ion Source Test Facility (ISTF), we measure the extracted current of high-charge state ions from a hot cathode Penning ion source. Producing high-charge states of Boron, Arsenic, and Phosphorous is of interest to the ion implantation community. Higher-charge states allow these doping agents to be accelerated to higher energies within the same accelerating electric fields. When used for doping silicon semiconductors, this allows for deeper implantation of the ions. We use Argon and Helium gas as a proxy to determine whether the Penning ion source could be used for this application as it is less toxic to work with. The ability to reach charge states of greater than 4+ with Argon and 1+ with Helium leads to the possibility of producing highe-charge states of ions used in the ion implantation industry. This paper shows the extracted beam currents of Ar3+ - Ar6+ and alpha-ions for the hot cathode Penning ion source with variations in the confining magnetic field (0.4 - 0.95 T), gas flow (0.3 - 10 sccm), and arc discharge current (1 - 3 A).  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOST053  
About • Received ※ 27 May 2022 — Revised ※ 15 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 16 June 2022
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WEPOPT005 Investigation of Polarized Proton Spin Coherence Time at Storage Rings sextupole, proton, storage-ring, betatron 1832
 
  • A.A. Melnikov, A.E. Aksentyev, Y. Senichev
    RAS/INR, Moscow, Russia
  • A.E. Aksentyev
    MEPhI, Moscow, Russia
  • E. Syresin
    JINR/VBLHEP, Dubna, Moscow region, Russia
 
  Funding: We appreciate a support of this study by the Russian Science Foundation grant 22-42-04419 and the ERC Advanced Grant of the European Union (proposal number 694340).
The idea of the Electric Dipole Moment (EDM) search using the storage ring with polarized beam demands long Spin Coherence Time (SCT). It is the time during which the RMS spread of the orientation of spins of all particles in the bunch reaches one radian. Long SCT is needed to observe a coherent effect on polarization induced by the EDM. The possibility of getting a 1000 s SCT for deuterons has been shown experimentally at COoler SYnchrotron (COSY), accelerator at FZJ Jülich, Germany. Reaching high values of SCT for protons is more challenging due to a higher anomalous magnetic moment. Obtaining sufficient proton SCT is obligatory for planned EDM search experiments at COSY and the ProtoType EDM Ring (PTR). It has been shown that the second order momentum compaction factor (alpha1) has to be optimized along with chromaticities to get high SCT. Three families of sextupoles have to be used. The optimal values of chromaticities and alpha1 are discussed. The racetrack option of PTR is investigated.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOPT005  
About • Received ※ 16 May 2022 — Revised ※ 14 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 02 July 2022
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WEPOPT006 Investigation of Spin-Decoherence in the NICA Storage Ring for the Future EDM-Measurement Experiment polarization, storage-ring, dipole, GUI 1835
 
  • A.E. Aksentyev, A.A. Melnikov, Y. Senichev
    RAS/INR, Moscow, Russia
  • A.E. Aksentyev
    MEPhI, Moscow, Russia
  • V. Ladygin, E. Syresin
    JINR, Dubna, Moscow Region, Russia
 
  Funding: We acknowledge support by the joint Deutsche ForschungsGemeinschaft (DFG) and Russian Science Foundation (RSF) grant 22-42-04419
A new experiment to measure electric dipole moments (EDMs) of elementary particles, based on the Frequency Domain method, has been proposed for implementation at the NICA facility (JINR, Russia). EDM experiments in general, being measurement-of-polarization experiments, require long spin-coherence times at around 1,000 seconds. The FD method involves a further complication (well paid off in orders of precision) of switching the polarity of the guiding field as part of its CW-CCW injection procedure. This latter procedure necessitates a calibration process, during which the beam polarization axis changes its orientation from the radial (used for the measurement) to the vertical (used for the calibration) direction. If this change occurs adiabatically, the beam particles’ spin-vectors follow the direction of the polarization axis, which undermines the calibration technique; however, concerns were raised as to whether violation of adiabaticity could damage spin-coherence.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOPT006  
About • Received ※ 16 May 2022 — Accepted ※ 15 June 2022 — Issue date ※ 22 June 2022  
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPOPT007 First Interaction Region Local Coupling Corrections in the LHC Run 3 coupling, optics, quadrupole, MMI 1838
 
  • F. Soubelet, T.H.B. Persson, R. Tomás García
    CERN, Meyrin, Switzerland
  • Ö. Apsimon, C.P. Welsch
    Cockcroft Institute, Warrington, Cheshire, United Kingdom
 
  Funding: This research is supported by the LIV. DAT Center for Doctoral Training, STFC and the European Organization for Nuclear Research
The successful operation of large scale particle accelerators depends on the precise correction of unavoidable magnetic field or magnet alignment errors present in the machine. During the LHC Run 2, local linear coupling in the interaction regions (IR) was shown to have a significant impact on the beam size, making its proper handling a necessity for Run 3 and the High Luminosity LHC (HL-LHC). A new approach to accurately minimise the local IR linear coupling based on correlated external variables such as the |C-| had been proposed, which relies on the application of a rigid waist shift in order to create an asymmetry in the IR optics. In this contribution, preliminary corrections from the 2021 beam test and the early 2022 commissioning are presented, as well as first results of the new method’s experimental configuration tests in the LHC Run 3 commissioning.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOPT007  
About • Received ※ 03 June 2022 — Revised ※ 15 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 19 June 2022
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WEPOPT025 Flat Beam Generation with the Phase Space Rotation Technique at KEK-STF emittance, gun, collider, cathode 1897
 
  • M. Kuriki, Z.J. Liptak
    HU/AdSM, Higashi-Hiroshima, Japan
  • S. Aramoto
    Hiroshima University, Higashi-Hiroshima, Japan
  • H. Hayano, X.J. Jin, Y. Seimiya, N. Yamamoto, Y. Yamamoto
    KEK, Ibaraki, Japan
  • S. Kashiwagi
    Tohoku University, Research Center for Electron Photon Science, Sendai, Japan
  • K. Sakaue
    The University of Tokyo, Graduate School of Engineering, Bunkyo, Japan
  • M. Washio
    RISE, Tokyo, Japan
 
  Flat beam generation from angular momentum dominated beam with a phase-space rotation technique is an unique method to manipulate the phase-space distribution of beam. As an application, the asymmetric emittance beam generation for linear colliders is considered to compensate the Beamstrahlung effect at Interaction point. By using this technique, the asymmetric beam can be generated directly with the injector, instead of radiation damping with a huge damping ring. We present the result of a proof-of-principle experiment at KEK-STF.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOPT025  
About • Received ※ 07 June 2022 — Revised ※ 14 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 23 June 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPOPT026 Possibilities for Upgrading to Polarized a SuperKEKB electron, polarization, lattice, cathode 1901
 
  • Z.J. Liptak
    HU/AdSM, Higashi-Hiroshima, Japan
 
  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 presentation lays out the goals and motivations of polarizing the electron beam, considers the necessary changes to the existing accelerator and their feasibility and reports progress in investigations to this point.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOPT026  
About • Received ※ 12 June 2022 — Revised ※ 11 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 16 June 2022
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WEPOPT033 Report of RHIC Beam Operation in 2021 operation, luminosity, target, electron 1912
 
  • C. Liu, P. Adams, E.N. Beebe, S. Binello, I. Blackler, M. Blaskiewicz, K.A. Brown, D. Bruno, B.D. Coe, K.A. Drees, A.V. Fedotov, W. Fischer, C.J. Gardner, C.E. Giorgio, X. Gu, T. Hayes, K. Hock, H. Huang, R.L. Hulsart, T. Kanesue, D. Kayran, N.A. Kling, B. Lepore, Y. Luo, D. Maffei, G.J. Marr, A. Marusic, K. Mernick, R.J. Michnoff, M.G. Minty, J. Morris, C. Naylor, S. Nemesure, M. Okamura, I. Pinayev, S. Polizzo, D. Raparia, G. Robert-Demolaize, T. Roser, J. Sandberg, V. Schoefer, S. Seletskiy, F. Severino, T.C. Shrey, P. Thieberger, M. Valette, A. Zaltsman, I. Zane, K. Zeno, W. Zhang
    BNL, Upton, New York, USA
 
  Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
The first priority of RHIC operation in 2021 was the Au+Au collisions at 3.85 GeV/nucleon, which is the lowest energy to complete the 3-year Beam Energy Scan II physics program, with RF-based electron cooling. In addition, RHIC also operated for several other physics programs including fixed target experiments, O+O at 100 GeV/nucleon, Au+Au at 8.65 GeV/nucleon, and d+Au at 100 GeV/nucleon. This report presents the operational experience and the results from RHIC operation in 2021. With Au+Au collisions at 3.85 GeV/nucleon reported in a separate report, this paper focuses on the operation conditions for the other programs mentioned above.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOPT033  
About • Received ※ 06 June 2022 — Revised ※ 14 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 05 July 2022
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WEPOPT039 Fine Decoupling Test and Simulation Study to Maintain a Large Transverse Emittance Ratio in Hadron Storage Rings emittance, coupling, proton, simulation 1935
 
  • Y. Luo, I. Blackler, M. Blaskiewicz, W. Fischer, A. Marusic, C. Montag, T.C. Shrey, D. Xu
    BNL, Upton, New York, USA
 
  Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy
I In previous and existing hadron storage rings, the horizontal and vertical emittances are normally the same or very close. For the Hadron Storage Ring (HSR) of the Electron-Ion Collider (EIC), the design proton transverse emittance ratio is 10:1. To maintain this large emittance ratio, we need to have an online fine decoupling system to prevent transverse emittance exchange. For this purpose, we carried out fine decoupling experiments in the Relativistic Heavy Ion Collider (RHIC) and reviewed its previous operational data. Analytical prediction and numerical simulation are preformed to estimate how small the global coupling coefficient should be to maintain a 10:1 emittance ratio.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOPT039  
About • Received ※ 19 May 2022 — Revised ※ 15 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 28 June 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPOPT053 Characterisation of Cooling in the Muon Ionization Cooling Experiment emittance, solenoid, collider, proton 1976
 
  • C.T. Rogers
    STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
  • M.A. Cummings
    Muons, Inc, Illinois, USA
 
  A high-energy muon collider could be the most powerful and cost-effective collider approach in the multi-TeV regime, and a neutrino source based on decay of an intense muon beam would be ideal for measurement of neutrino oscillation parameters. Muon beams may be created through the decay of pions produced in the interaction of a proton beam with a target. The muons are subsequently accelerated and injected into a storage ring where they decay producing a beam of neutrinos, or collide with counter-rotating antimuons. Cooling of the muon beam would enable more muons to be accelerated resulting in a more intense neutrino source and higher collider luminosity. Ionization cooling is the novel technique by which it is proposed to cool the beam. The Muon Ionization Cooling Experiment collaboration has constructed a section of an ionization cooling cell and used it to provide the first demonstration of ionization cooling. Here the observation of ionization cooling is described. The results of the further analysis of the data is presented, including studies in different magnet configurations and with more detailed understanding of the detector systematic uncertainty.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOPT053  
About • Received ※ 06 June 2022 — Revised ※ 14 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 23 June 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPOPT064 Simulations and Measurements of Luminosity at SuperKEKB simulation, luminosity, resonance, impedance 2011
 
  • D. Zhou, Y. Funakoshi, K. Ohmi, Y. Ohnishi
    KEK, Ibaraki, Japan
  • Y. Zhang
    IHEP, Beijing, People’s Republic of China
 
  The interplay of beam-beam interaction, machine imperfections, and beam coupling impedance makes it difficult to predict the luminosity performance of SuperKEKB. Since 2020, the crab waist scheme was introduced to SuperKEKB to suppress beam-beam resonances. The coherent beam-beam head-tail instability and beam-beam driven synchro-betatron resonances due to large crossing angle can drive horizontal blowup, which cannot be suppressed by crab waist. The longitudinal impedance modulates the synchrotron motion and therefore affects beam-beam instability. In this paper, we compare simulations and measurements of luminosity and discuss the challenges and direction toward developing a predictable luminosity simulation model for SuperKEKB.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOPT064  
About • Received ※ 13 June 2022 — Revised ※ 15 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 30 June 2022
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WEPOTK002 Investigation, Simulation and First Measurements of a 2m Long Electron Column Trapped in a Gabor Lens Device electron, plasma, focusing, diagnostics 2023
 
  • K.I. Thoma, M. Droba, O. Meusel
    IAP, Frankfurt am Main, Germany
 
  Various Gabor-Lenses (GL) were investigated at Goethe University. Confinement of sufficient electron densities (ne~1E15m3) were reached without any external source of electrons. Focusing of ion beams by low energy was demonstrated, long term stability and reproducibility were approved. Main differences compared to experiments and investigations of the pure non-neutral in Penning-Malmberg traps are higher residual gas pressure and therefore higher collision rates, higher bulk temperatures, self-sustaining electron production process, much higher evaporation cooling rate. GL2000 is a new 2m long device and was mainly designed for focusing of ion beams in energy ranges up to GeV but also for investigation of non-neutral plasma parameters. The confined electron column is much longer compared to previous constructed Lenses. This makes ion and hadron beam focussing much more efficient, in addition new physical phenomena can be expected and investigated. Simulation results of steady- and thermal equilibrium states with various external parameters and first measurements will be presented. The first operational tests show that it is possible to confine a two-meter long electron column.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOTK002  
About • Received ※ 20 May 2022 — Revised ※ 13 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 22 June 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPOTK004 Status and Upgrade Plan of the MR Ring RF Systems in J-PARC cavity, operation, power-supply, proton 2031
 
  • K. Hasegawa, K. Hara, C. Ohmori, Y. Sugiyama, M. Yoshii
    KEK, Ibaraki, Japan
  • M. Nomura, H. Okita, T. Shimada, F. Tamura, M. Yamamoto
    JAEA/J-PARC, Tokai-mura, Japan
 
  The J-PARC Main Ring (MR) is a high intensity proton accelerator and delivers 30 GeV proton beams for the long-base line neutrino experiment and the hadron experiments. At present, the beam intensity supplied to the neutrino experiment reached 520 kW with a cycle time of 2.48 s. Toward the design beam power of 750 kW and future goal of 1.3 MW, we chose shortening the MR operation cycle. Accelerating time is shortened in order to shorten the cycle, so a high accelerating voltage is required. Therefore, it is necessary to upgrade the RF systems. This RF upgrade expands the current nine RF systems to a total of thirteen. We are planning to fabricate four RF power sources and add four additional cavities that are recombined with existing cavities. The present status and upgrade plan of the MR RF systems are reported.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOTK004  
About • Received ※ 08 June 2022 — Revised ※ 13 June 2022 — Accepted ※ 23 June 2022 — Issue date ※ 07 July 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPOTK007 Simulating Quasi-Integrable Optics with Space Charge in the IBEX Paul Trap octupole, lattice, space-charge, resonance 2040
 
  • J.A.D. Flowerdew
    University of Oxford, Oxford, United Kingdom
  • D.J. Kelliher, S. Machida, S.L. Sheehy
    STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom
 
  Funding: Royal Society
The intensity frontier has called for new initiatives in hadron accelerator design in order to accommodate space charge dominated beams. Octupoles are often used to damp beam instabilities caused by space charge, however the insertion of octupole magnets leads to a nonintegrable lattice which reduces the area of stable particle motion. One proposed solution is Quasi-Integrable optics (QIO), where the octupoles are inserted between sections of a specific lattice insertion called a T-insert. An octupole with a strength that scales as 1/beta3(s) is applied in the drift region, where the horizontal and vertical beta functions are equal, to create a time independent octupole field. This leads to a lattice with a time-independent Hamiltonian which is robust to small perturbations. IBEX is a Paul trap which allows the transverse dynamics of a collection of trapped particles to be studied, mimicking the propagation through multiple quadrupole lattice periods, whilst remaining stationary in the laboratory frame. In order to test QIO at the IBEX experiment, it has recently undergone an upgrade to allow for the creation of octupole fields. We present our design of the IBEX experiment upgrade along with simulation results of our proposed experiment to test QIO with space charge.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOTK007  
About • Received ※ 19 May 2022 — Revised ※ 14 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 18 June 2022
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WEPOTK008 Future Neutrino Beam Studies Under the Framework of Physics Beyond Colliders focusing, target, background, detector 2044
 
  • E.G. Parozzi
    Universita Milano Bicocca, MILANO, Italy
  • J. Bernhard, M. Brugger, N. Charitonidis, C.A. Mussolini, M.L.A. Perrin-Terrin
    CERN, Meyrin, Switzerland
  • C.A. Mussolini
    JAI, Oxford, United Kingdom
  • Y. Nagai
    ELTE, Budapest, Hungary
  • Y. Nagai
    Colorado University at Boulder, Boulder, Colorado, USA
 
  A Physics Beyond Colliders (PBC) initiative was recently established at CERN to exploit the full scientific potential of its accelerator complex and scientific infrastructure to tackle fundamental open questions in particle physics through experiments complementary to those in current and future colliders. This initiative brings together similar studies to optimize resources globally in order to reach a common goal and promote scientific development efficiently. In this work, we present the work performed by the Conventional Beam Working Group (CBWG) and specifically from the Neutrino Beams (NB) subgroup. The subgroup currently deals with two novel neutrino-tagged beams projects, ENUBET and NUTAG, as well as with a more classic, low energy, beamline dedicated to hadron cross-sections for neutrino beams with the NA61 experiment already installed in the H2 beamline of the CERN North Area. This contribution will detail the advances made with these three projects as well as their status and future plans.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOTK008  
About • Received ※ 08 June 2022 — Revised ※ 17 June 2022 — Accepted ※ 23 June 2022 — Issue date ※ 27 June 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPOTK010 The Second Long Shutdown of the LHC and Its Injectors: Feedback from the Accelerator Coordination and Engineering Group site, operation, GUI, database 2052
 
  • A.-L. Perrot, M. Bernardini, S. Chemli, J.-P. Corso, J. Coupard, F.B. Dos Santos Pedrosa, J. Etheridge, K. Foraz, S. Grillot, J.M. Jimenez, B. Nicquevert, S. Petit, J.Ph.G.L. Tock, E. Vergara Fernandez
    CERN, Meyrin, Switzerland
 
  The operation of the Large Hadron Collider (LHC) at CERN started in September 2008. Every 5 or 6 years, Long Shutdowns (LS) are programmed to execute time-intensive ordinary and extra-ordinary maintenance of the LHC and its injectors. The second LS (LS2) started in December 2018 and was completed end 2020 for the injectors and early 2022 for the LHC. A huge number of maintenance, consolidation and upgrade activities, especially the upgrade of the injectors complex, were performed with challenges at various levels, from technical, to organizational and managerial. This paper presents the applied methodology put in place by the Accelerator Coordination & Engineering (EN-ACE) Group, in charge of the technical coordination of the activities for the interventions and changes to the LHC and its injectors, to ensure that the installation activities are performed safely, meeting the required high level of quality, while optimizing the schedule. It highlights key points of success and lessons learnt in terms of general coordination, quality assurance, configuration and layout management, spatial integration, planning and scheduling, operational safety, logistics and worksite coordination  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOTK010  
About • Received ※ 03 June 2022 — Revised ※ 10 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 03 July 2022
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WEPOTK026 Commissioning of the ELENA Electrostatic Transfer Lines for the Antimatter Facility at CERN quadrupole, proton, extraction, antiproton 2110
 
  • Y. Dutheil, W. Bartmann, C. Carli, M.A. Fraser, D. Gamba, L. Ponce
    CERN, Meyrin, Switzerland
 
  ELENA is a small synchrotron ring that decelerates antiprotons down to a kinetic energy of 100 keV. With an experimental complex capable of housing up to 9 different experiments operating simultaneously, the transfer line design needed to be highly flexible. The low energy of the beam transported allowed the exploitation of electrostatic devices instead of magnets, to simplify design, production and operation. This contribution presents the systematic characterisation of the beam optics at the different experimental handover locations during beam commissioning using H ions from an external source, as well as the performance of the lines in operation with antiprotons. Finally, the effect of stray fields created by the experimental setup will be presented and compared with the first measurements.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOTK026  
About • Received ※ 10 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 28 June 2022  
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WEPOTK029 Advances in Low Energy Antimatter Beam Generation and Manipulation proton, antiproton, simulation, electron 2118
 
  • C.P. Welsch
    Cockcroft Institute, Warrington, Cheshire, United Kingdom
  • C.P. Welsch
    The University of Liverpool, Liverpool, United Kingdom
 
  Funding: This project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska Curie grant agreement No 721559.
The Accelerators Validating Antimatter physics (AVA) project has enabled an interdisciplinary and cross-sector R&D program on low energy antimatter research. The network comprises 13 universities, 9 national and inter-national research centers and 13 partners from industry. Between 2016 and 2021, AVA has successfully trained 16 early-stage researchers that were based at universities, research centers and companies across Europe where they carried out cutting edge research into low energy antimat-ter physics and related technologies. This contribution presents several research highlights that originated within or on the basis of AVA: Results from studies into carbon nano-tubes as field emitters for cold electron beams with supe-rior beam quality, the design of a low energy negative ion injection beamline for experiments with antiprotonic atoms, and studies into realistic simulations of antiproton deceleration in foil degraders.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOTK029  
About • Received ※ 07 June 2022 — Revised ※ 14 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 27 June 2022
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WEPOTK031 Low-Energy Negative Ion Injection Beamline for Experiments with Antiprotonic Atoms at AEgIS proton, antiproton, focusing, injection 2126
 
  • V. Rodin, A. Farricker, C.P. Welsch
    The University of Liverpool, Liverpool, United Kingdom
  • G. Cerchiari
    Institut für Experimentalphysik, Universtität Innsbruck, Innsbruck, Austria
  • M. Doser, G. Khatri
    CERN, Meyrin, Switzerland
  • G. Kornakov
    Warsaw University of Technology, Warsaw, Poland
  • C.P. Welsch
    Cockcroft Institute, Warrington, Cheshire, United Kingdom
 
  Funding: Research was funded by Warsaw University of Technology within the Excellence Initiative: Research University (IDUB) programme
Interaction of low-energy antiprotons with nuclear targets provided fundamental knowledge about proton and neutron densities of many nuclei through the capture process, cascade on lower electron orbits, and annihilation with the nucleon. The expelled electrons produce X-rays and with the recoil particles after annihilation, thus, a sufficient amount of information can be obtained about this interaction. However, all previous experiments were done via formation of antiprotonic atoms in solid or gaseous targets. Therefore, annihilation occurs prior reaching the S or P orbital levels and precise measurements are missing. Recently, AEgIS collaboration proposed a conceptually new experimental scheme. The creation of cold antiprotonic atoms in a vacuum guarantees the absence of the Stark effect. And with the sub-ns timing and synchronization, the previous experimental obstacles would be resolved. This will allow studying atomic properties, evolution, and fragmentation process with improved precision and extended lifetimes. In this contribution, we present an overview of the experimental scheme as well as various aspects of negative ion injection beamline into the AEgIS experiment.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOTK031  
About • Received ※ 08 June 2022 — Accepted ※ 10 June 2022 — Issue date ※ 13 June 2022  
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WEPOTK032 Fast Electromagnetic Models of Existing Beamline Simulations quadrupole, simulation, focusing, proton 2130
 
  • S. Padden, E. Kukstas, P. Pusa, V. Rodin, C.P. Welsch
    The University of Liverpool, Liverpool, United Kingdom
  • S. Padden, V. Rodin, C.P. Welsch
    Cockcroft Institute, Warrington, Cheshire, United Kingdom
 
  The AD-ELENA complex decelerates antiprotons to ener- gies of 100 keV before transport to experiments through elec- trostatic transfer lines. Transfer line optics are traditionally designed from a lattice based approach and are unaffected by external effects. Presented is a method of rapidly proto- typing MAD-X simulations into G4Beamline models which propagate particles via electromagnetic fields rather than idealised optical lattice parameters. The transfer line to the ALPHA experiment is simulated in this approach. Due to the presence of fringe fields disagreement is found between the two models. Using an error minimisation technique, revised quadrupole strengths are found which improve agreement by 30% without any manual adjustment.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOTK032  
About • Received ※ 06 June 2022 — Revised ※ 13 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 20 June 2022
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WEPOTK033 Layouts for Feasibility Studies of Fixed-Target Experiments at the LHC target, dipole, proton, collimation 2134
 
  • P.D. Hermes, K.A. Dewhurst, A.S. Fomin, D. Mirarchi, S. Redaelli
    CERN, Meyrin, Switzerland
 
  The Physics Beyond Colliders (PBC) study investigates means of exploiting the potential of the CERN accelerator complex to complement the laboratory’s scientific programme at the main Large Hadron Collider (LHC) experiments. The LHC fixed-target (FT) working group studies new experiments at beam energies up to 7 TeV. One of the proposed experiments is based on a bent crystal, part of the collimation hierarchy, to extract secondary halo particles and steer them onto a target. A second bent crystal immediately downstream of the target is used to study electric and magnetic dipole moments of short-lived baryons. The possibility to install a test stand in the LHC off-momentum collimation Insertion Region (IR3) to demonstrate the feasibility and performance of this challenging scheme is currently under investigation. The integration of a spectrometer magnet into the present layout is particularly critical. In this contribution, we study a possible test setup that could be used in LHC Run 3.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOTK033  
About • Received ※ 08 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 28 June 2022  
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WEPOTK034 LHC Beam Collimation During Extended β*-Levelling in Run 3 collimation, luminosity, operation, optics 2138
 
  • F.F. Van der Veken, R. Bruce, M. Hostettler, D. Mirarchi, S. Redaelli
    CERN, Meyrin, Switzerland
 
  During the third operational Run of the Large Hadron Collider at CERN, starting in 2022, the bunch population will be increased to unprecedented levels requiring to deploy β*-levelling of the luminosity over a wide range of values to cope with the limitations imposed by event pile-up at the experiments and heat load on the triplets induced by collision debris. During this levelling, both beam optics and orbit change in various areas of the ring, in particular around the high-luminosity experiments, where several collimators are installed. This requires adapting the collimation system settings adequately, in particular for the tertiary collimators (TCTs) that protect the inner-triplet magnets. To this end, two strategies are considered: keeping collimators at fixed physical openings while shifting their centres following the beam orbit, or varying also the collimator openings. The latter strategy is planned when the larger optics range will be deployed. In this paper, we investigate several loss scenarios at the TCTs in different steps of the levelling, and present the proposed collimator settings during Run 3.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOTK034  
About • Received ※ 07 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 07 July 2022  
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WEPOTK036 Progress on Electron Beam Optimization for FLASH Radiotherapy Experiment at Chiang Mai University electron, simulation, radiation, linac 2146
 
  • K. Kongmali, P. Apiwattanakul, S. Rimjaem, J. Saisut, C. Thongbai
    Chiang Mai University, Chiang Mai, Thailand
  • P. Apiwattanakul, N. Kangrang
    Chiang Mai University, PBP Research Facility, Chiang Mai, Thailand
  • M. Jitvisate
    Suranaree University of Technology, Nakhon Ratchasima, Thailand
  • P. Lithanatudom
    IST, Chiang Mai, Thailand
 
  At present, one of diseases that kills many people worldwide is cancer. The FLASH radiotherapy (RT) is a promising cancer treatment under study. It involves the fast delivery of RT at much higher dose rates than those currently used in clinical practice. The very short time of exposure leads to the destruction of the cancer cells, while the nearby normal cells are less damaged as compared with conventional RT. This work focuses on study of FLASH-RT experiment using electron beams produced from the accelerator system at the PBP-CMU Electron Linac Laboratory. The structure and properties of our electron pulses with microbunches in picosecond time scale and macropulses in microsecond time scale match well to FLASH-RT requirement. To optimize the condition for experiment, the electron beam simulations are performed by varying energy, charge and bunch length. The 25 MeV electrons energy before hitting the window for 50 and 100 pC bunch length have a bunch length of 1.16 and 1.97 ps. The transverse rms beam sizes of 50 pC and 100 pC bunch charges have the differences between ASTRA and GEANT4 from 7.90 % to 34.0 %. The optimized electron beam properties from this study will be used as the guideline for further simulation and experiment preparation.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOTK036  
About • Received ※ 08 June 2022 — Revised ※ 14 June 2022 — Accepted ※ 20 June 2022 — Issue date ※ 22 June 2022
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WEPOTK040 Spin-Tracking Simulations in a COSY Model Using Bmad simulation, resonance, dipole, polarization 2158
 
  • M. Vitz
    FZJ, Jülich, Germany
 
  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 (Jülich Electric Dipole moment Investigations) in Jülich has performed a direct EDM measurement for deuterons with the so called precurser experiments at the storage ring COSY (COoler SYnchrotron). In order to understand the measured data and to disentangle an EDM signal from systematic effects, spin tracking simulations in an accurate simulation model of COSY are needed. Therefore a model of COSY was implemented using the software library Bmad. Systematic effects were considered by including element misalignments, effective dipole shortening and steerer kicks. These effects rotate the invariant spin axis additional 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.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOTK040  
About • Received ※ 02 June 2022 — Revised ※ 13 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 05 July 2022
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WEPOTK050 The Report of Machine Studies Related to the Vertical Beam Size Blow-Up in SuperKEKB LER emittance, luminosity, beam-beam-effects, coupling 2169
 
  • S. Terui, H. Fukuma, Y. Funakoshi, T. Ishibashi, T. Nakamura, K. Ohmi, Y. Ohnishi, M. Tobiyama, R. Ueki
    KEK, Ibaraki, Japan
 
  In the Low Energy Ring (LER) for positrons in the SuperKEKB, a vertical beam size blow-up was observed when the bunch current was approximately 1 mA. If a beam size blow-up occurs, the design luminosity cannot be achieved. Therefore, beam size blow-ups must be pre-vented. According to calculations, the bunch current threshold of the Transverse Mode Coupling instability (TMCI) is 2 mA or more, and the observed value is 50% or smaller. This vertical beam size blow-up cannot be explained by ordinary TMCI. This paper shows that by analyzing factors such as beam oscillation, the cause of the vertical beam size blow-up was determined. The study results showed that the vertical beam size blow-up in the LER was caused by the oscillations of the -1 mode.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOTK050  
About • Received ※ 17 May 2022 — Accepted ※ 22 June 2022 — Issue date ※ 25 June 2022  
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WEPOTK053 Simulation of Bunch Formation for the Mu2e Experiment proton, impedance, simulation, dipole 2180
 
  • K.P. Harrig, E. Prebys
    UCD, Davis, California, USA
  • V.P. Nagaslaev, S.J. Werkema
    Fermilab, Batavia, Illinois, USA
 
  Funding: Grant DE-SC0019254, The U.S. Department of Energy, Office of Science and Fermi Research Alliance, LLC Contract No. DE-AC02-07CH11359
The Fermilab Recycler is an 8 GeV storage ring composed of permanent magnets that was crucial to the success of the Fermilab Tevatron Collider program. It is currently being used to slip-stack protons for the high energy neutrino program and to re-bunch protons for use in the Muon g-2 and Mu2e experiments. For the latter applications, the Recycler re-bunches each 1.6 µs "batch" from the Fermilab Booster into four 2.5 MHz bunches. For the Mu2e experiment, it is crucial that beam more than 125 ns from the nominal bunch center be suppressed by at least a factor of 1E-5. While bunch formation is currently in operation for the g-2 experiment, this out of time requirement has not been met, and the reason is not understood. This work presents a simulation of bunch formation in the Recycler, in an effort to understand the reason for this excessive out of time beam and to search for a way to reduce it.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOTK053  
About • Received ※ 30 May 2022 — Revised ※ 16 June 2022 — Accepted ※ 23 June 2022 — Issue date ※ 11 July 2022
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WEPOTK054 Experimental Verification of DARHT Axis 1 Injector PIC Simulations simulation, cathode, emittance, solenoid 2183
 
  • A.F. Press, M.A. Jaworski, D.C. Moir, S. Szustkowski
    LANL, Los Alamos, New Mexico, USA
 
  Validated particle in cell (PIC) simulations of the DARHT Axis 1 injector have the potential to reduce accelerator downtime, assist experimental data analysis and improve accelerator tunes. To realize these benefits, the simulations must be validated with experimental results. In this work, the particle in cell code Chicago is used to simulate the injector region of the dual-axis radiographic hydrodynamic test facility (DARHT) first axis. These simulations are validated against experiment using measured anode-cathode voltage, beam current at three positions, optical transition radiation and previously calculated emittance. Since all of these measurements contain some variation, the respective simulation parameters are varied to understand their effect. The resulting simulated beam current distributions can then be compared to the measured 2RMS radius. This resulted in a reasonably well validated simulation model. Some inconstancy between simulated and measured results still exists, which future work will address.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOTK054  
About • Received ※ 06 June 2022 — Revised ※ 10 June 2022 — Accepted ※ 04 July 2022 — Issue date ※ 05 July 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPOTK058 Experimental Study of the Transverse Mode Coupling Instability with Space-Charge at the CERN SPS space-charge, emittance, simulation, lattice 2193
 
  • X. Buffat, H. Bartosik
    CERN, Meyrin, Switzerland
 
  Past studies on the Transverse Mode Coupling Instability (TMCI) suggested that it can be suppressed in the presence of space-charge forces. Recent developments in this field show that for higher strength, space-charge forces leads to other types of instabilities. We investigate the characteristics of these instabilities by means of stability threshold measurements at the CERN SPS for various intensities, longitudinal and transverse emittances. These observations are compared to numerical tracking simulations.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOTK058  
About • Received ※ 03 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 18 June 2022  
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPOTK060 Prospects of Ultrafast Electron Diffraction Experiments at Sealab electron, SRF, cavity, gun 2201
 
  • B. Alberdi-Esuain, J.-G. Hwang, T. Kamps, A. Neumann, J. Völker
    HZB, Berlin, Germany
  • T. Kamps
    HU Berlin, Berlin, Germany
 
  Ultrafast Electron Diffraction (UED) is a pump-probe experimental technique that aims to image the structural changes that happen in a target structure due to photo-excitation. Development of MeV UED capabilities is one of the main objectives at Sealab, a superconducting RF accelerator facility being commissioned in Helmholtz-Zentrum Berlin. In order to perform UED experiments, the optimization of temporal resolution is of the utmost importance. The composition of the SRF Photoinjector, currently the main beam-line in Sealab, offers superb flexibility to manipulate the longitudinal phase-space of the electron bunch. At the same time, the CW operation of the accelerator provides an enhanced beam stability compared to warm guns, together with MHz repetition rates. This work aims to show the capacity of the SRF Photoinjector in Sealab to reach the required temporal resolution and explain the development and current status of the necessary tools to perform UED experiments at the facility.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOTK060  
About • Received ※ 08 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 03 July 2022  
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WEPOMS029 Modeling of the Optical Stochastic Cooling at the IOTA Storage Ring Using ELEGANT radiation, kicker, coupling, undulator 2307
 
  • A.J. Dick, P. Piot
    Northern Illinois University, DeKalb, Illinois, USA
  • J.D. Jarvis
    Fermilab, Batavia, Illinois, USA
  • P. Piot
    ANL, Lemont, Illinois, USA
 
  In support of the Optical Stochastic Cooling (OSC) experiment at IOTA, we implemented a high-fidelity model of OSC in ELEGANT. The element is generalizable to any OSC experiment and captures three main behaviors; (i) the longitudinal time of flight OSC, (ii) the effects between the transverse motion of particles in the beam and the transverse distribution of undulator radiation, and (iii) the incoherent contributions of neighboring particles. Together these produce a highly accurate model of OSC and were benchmarked using the results from the IOTA OSC experiment.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOMS029  
About • Received ※ 14 June 2022 — Revised ※ 17 June 2022 — Accepted ※ 05 July 2022 — Issue date ※ 06 July 2022
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WEPOMS030 A Path-Length Stability Experiment for Optical Stochastic Cooling at the Cornell Electron Storage Ring lattice, radiation, storage-ring, dipole 2311
 
  • S.J. Levenson, M.B. Andorf, I.V. Bazarov, V. Khachatryan, J.M. Maxson, D.L. Rubin, S. Wang
    Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
 
  Funding: This work was supported by the U.S. National Science Foundation under Award PHY-1549132, the Center for Bright Beams and NYSTAR award C150153.
To achieve sufficient particle delay with respect to the optical path in order to enable high gain amplification, the design of the Optical Stochastic Cooling (OSC) experiment in the Cornell Electron Storage Ring (CESR) places the pickup (PU) and kicker (KU) undulators approximately 80 m apart. The arrival times at the KU of particles and the light they produce in the PU must be synchronized to an accuracy of less than an optical wavelength, which for this experiment is 780 nm. To test this synchronization, a planned demonstration of the stability of the bypass in CESR is presented where, in lieu of undulators, an interference pattern formed with radiation from two dipoles flanking the bypass is used. In addition to demonstrating stability, the fringe visibility of the pattern is related to the cooling ranges, a critical parameter needed for OSC. We present progress on this stabilization experiment including the design of a second-order isochronous bypass, as well as optimizations of the Dynamic Aperture (DA) and injection efficiency.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOMS030  
About • Received ※ 08 June 2022 — Revised ※ 17 June 2022 — Accepted ※ 23 June 2022 — Issue date ※ 26 June 2022
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WEPOMS031 Light Path Construction for an Optical Stochastic Cooling Stability Test at the Cornell Electron Storage Ring radiation, synchrotron, optics, feedback 2315
 
  • S.J. Levenson, M.B. Andorf, I.V. Bazarov, D.C. Burke, J.M. Maxson, D.L. Rubin, S. Wang
    Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
 
  Funding: This work was supported by the U.S. National Science Foundation under Award PHY-1549132, the Center for Bright Beams and NYSTAR award C150153.
An experiment at the Cornell Electron Storage Ring (CESR) to test the optical path-length stability of a bypass suitable for Optical Stochastic Cooling (OSC) is being pursued. The approximately 80 m light path for this experiment has been assembled, and synchrotron light has been successfully propagated from both sources. A feedback system based on an Electro-Optic Modulator (EOM) to correct the path-error accumulated in both the light and particle path has been table-top tested. We present on the design and construction of the light optics for the OSC stability experiment at CESR.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOMS031  
About • Received ※ 08 June 2022 — Revised ※ 15 June 2022 — Accepted ※ 21 June 2022 — Issue date ※ 03 July 2022
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WEPOMS036 Accelerating Linear Beam Dynamics Simulations for Machine Learning Applications simulation, space-charge, controls, GPU 2330
 
  • O. Stein, I.V. Agapov, A. Eichler, J. Kaiser
    DESY, Hamburg, Germany
 
  Machine learning has proven to be a powerful tool with many applications in the field of accelerator physics. Training machine learning models is a highly iterative process that requires large numbers of samples. However, beam time is often limited and many of the available simulation frameworks are not optimized for fast computation. As a result, training complex models can be infeasible. In this contribution, we introduce Cheetah, a linear beam dynamics framework optimized for fast computations. We show that Cheetah outperforms existing simulation codes in terms of speed and furthermore demonstrate the application of Cheetah to a reinforcement-learning problem as well as the successful transfer of the Cheetah-trained model to the real world. We anticipate that Cheetah will allow for faster development of more capable machine learning solutions in the field, one day enabling the development of autonomous accelerators.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOMS036  
About • Received ※ 07 June 2022 — Revised ※ 14 June 2022 — Accepted ※ 01 July 2022 — Issue date ※ 01 July 2022
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THOXGD1 ELENA - From Commissioning to Operation proton, antiproton, MMI, operation 2391
 
  • L. Ponce, L. Bojtár, C. Carli, B. Dupuy, Y. Dutheil, P. Freyermuth, D. Gamba, L.V. Jørgensen, B. Lefort, S. Pasinelli
    CERN, Meyrin, Switzerland
 
  In 2021 the Extra Low ENergy Antiproton ring (ELENA) moved from commissioning into the physics production phase providing 100 keV antiprotons to the newly connected experiments paving the way to an improved trapping efficiency by one to two orders of magnitude compared to the AD era. After recalling the major work undertaken during the CERN Long Shutdown 2 (2019-2020) in the antiproton deceleration complex, details will be given on the ELENA ring and the new electrostatic transfer line beam commissioning using an ion source. Sub-sequentially, the progress from commissioning with ions to operation with antiprotons will be described with emphasis on the achieved beam performance. Finally, the impact on the performance of the main hardware systems will be reviewed.  
slides icon Slides THOXGD1 [9.720 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THOXGD1  
About • Received ※ 07 June 2022 — Revised ※ 15 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 01 July 2022
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THOYGD1 Experimental Verification of Several Theoretical Models for ChDR Description radiation, electron, diagnostics, beam-diagnostic 2420
 
  • K. Łasocha
    Jagiellonian University, Kraków, Poland
  • C. Davut
    The University of Manchester, Manchester, United Kingdom
  • P. Karataev
    Royal Holloway, University of London, Surrey, United Kingdom
  • T. Lefèvre, S. Mazzoni, E. Senes
    CERN, Meyrin, Switzerland
  • C. Pakuza
    Oxford University, Physics Department, Oxford, Oxon, United Kingdom
  • A. Schloegelhofer
    TU Vienna, Wien, Austria
 
  In recent years the potential of using Cherenkov Diffraction Radiation (ChDR) as a tool for non-invasive beam diagnostics has been thoroughly investigated. Although several theoretical models of ChDR have been developed, differences in their assumptions result in inconsistent predictions. The experimental verification is therefore needed in order to fully understand ranges of validity of available models. In this contribution we present a detailed theoretical study of the radiation yield as a function of the beam-radiator distance. Following identification of beam parameters and frequency range for which differences between the model predictions are most prominent, we compare theoretical estimates with the results of a dedicated experiment.  
slides icon Slides THOYGD1 [0.838 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THOYGD1  
About • Received ※ 08 June 2022 — Revised ※ 15 June 2022 — Accepted ※ 19 June 2022 — Issue date ※ 27 June 2022
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THPOST001 Temperature Effects on the PETRA III Tunnel Stability operation, synchrotron, storage-ring, emittance 2432
 
  • M. Schaumann, M. Bieler, J. Keil, J. Klute, L. Liao, R. Wanzenberg
    DESY, Hamburg, Germany
 
  The tunnel of the synchrotron light source PETRA III is build from separate segments that are joint together every 24 m. The normal conducting magnets heat up the tunnel when operating, which leads to an expansion of the concrete walls and floor introducing movements between the tunnels segments. Especially during warm-up periods after shutdowns, this results in a drift of the accelerator elements that is transferred on the circulating beam over a duration of days, weeks or months according to the length of the cool-down period. This paper shows that not only inside temperature effects but also seasonal temperature changes are relevant.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOST001  
About • Received ※ 07 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 20 June 2022  
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THPOST018 The Design of a Second Beamline for the CLEAR User Facility at CERN quadrupole, focusing, electron, dipole 2479
 
  • L.A. Dyks, R. Corsini, P. Korysko
    CERN, Meyrin, Switzerland
  • P. Burrows
    JAI, Oxford, United Kingdom
  • P. Burrows, P. Korysko
    Oxford University, Physics Department, Oxford, Oxon, United Kingdom
 
  The CERN Linear Electron Accelerator for Research (CLEAR) has been operating as a general user facility since 2017 providing beams for a wide range of user experiments. However, with its current optical layout, the beams available to users are not able to cover every request. To overcome this, a second experimental beamline has been proposed. In this paper we discuss the potential optics of the new line as well as detailing the hardware required for its construction. Branching from the current beamline, via a dogleg chicane that could be used for bunch compression, the new beamline would provide an additional in-air test stand to be available to users. The beamline before the test stand would utilise large aperture quadrupoles to allow the irradiation of large target areas or strong focussing of beams onto a target. In addition to this there would also be further in-vacuum space to install experiments.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOST018  
About • Received ※ 07 June 2022 — Revised ※ 16 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 19 June 2022
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THPOST023 Current Status of the FFA@CEBAF Energy Upgrade Study dipole, linac, permanent-magnet, extraction 2494
 
  • R.M. Bodenstein, J.F. Benesch, S.A. Bogacz, A. Coxe, K.E. Deitrick, B.R. Gamage, G.A. Krafft, K.E.Price. Price, Y. Roblin, A. Seryi
    JLab, Newport News, Virginia, USA
  • J.S. Berg, S.J. Brooks, D. Trbojevic
    BNL, Upton, New York, USA
  • D. Douglas
    Douglas Consulting, York, Virginia, USA
  • G.H. Hoffstaetter
    Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
  • V.S. Morozov
    ORNL RAD, Oak Ridge, Tennessee, USA
 
  Funding: This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics under contract DE-AC05-06OR23177.
This work will describe the current status of the FFA@CEBAF energy upgrade feasibility studies. Technical updates are given, but more specific details are left to separate contributions. Specifically, this work will discuss improvements to the FFA arcs, a new recirculating injector proposal, and numerous modifications to the current 12 GeV CEBAF which will be required, such as the spreaders and recombiners architecture, splitters (time-of-flight chicanes), the extraction system, and the hall lines.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOST023  
About • Received ※ 08 June 2022 — Revised ※ 15 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 06 July 2022
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THPOST027 Fabrication of Robust Thermal Transition Modules and First Cryogenic Experiment with the Refurbished COLDDIAG vacuum, operation, cryogenics, diagnostics 2505
 
  • H.J. Cha, N. Glamann, A.W. Grau, A.-S. Müller, D. Saez de Jauregui
    KIT, Eggenstein-Leopoldshafen, Germany
 
  Funding: This work is supported by the BMBF project 05H18VKRB1 HIRING (Federal Ministry of Education and Research).
Two sets of thermal transition modules as a key component for the COLDDIAG (cold vacuum chamber for beam heat load diagnostics) refurbishment were manufactured, based on the previous design study. The modules are installed in the existing COLDDIAG cryostat and tested with an operating temperature of approximately 50 K at both a cold bore and a thermal shield. This cool-down experiment is a preliminary investigation aiming at beam heat-load studies at the FCC-hh where the beam screens will be operated at almost the same temperature. In this contribution, we report the fabrication processes of the mechanically robust transition modules and the first thermal measurement results with the refurbished COLDDIAG in a cryogenic environment. The static heat load in the refurbished cryostat remains unchanged, compared to that in the former one (4-K cold bore and 50-K shield with thin transitions), despite the increase in the transition thickness. It originates from the identical temperature at the cold bore and the shield, which can theoretically allow the heat intakes by thermal conduction and radiation between them to vanish.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOST027  
About • Received ※ 16 May 2022 — Accepted ※ 13 June 2022 — Issue date ※ 10 July 2022  
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPOST029 Upgrade of the Slow Extraction System of the Heidelberg Ion-Beam Therapy Centre’s Synchrotron extraction, synchrotron, feedback, FEL 2509
 
  • E. Feldmeier, R. Cee, E.C. Cortés García, M. Galonska, Th. Haberer, M. Hun, A. Peters, S. Scheloske, C. Schömers
    HIT, Heidelberg, Germany
 
  The Heidelberg Ion-Beam Therapy Centre HIT consists of a linear accelerator and a synchrotron to provide carbon ions, helium ions and protons for the clinical use as well as oxygen ions for experiments. The RF-KO slow extraction method is used to extract the particles from the synchrotron. To improve the spill quality of the extracted beam a new RF-signal was investigated which increases the R-value from 92.5% to 97,5%. The signal is a multiband RF signal broadened with a random BPSK at 3 frequency bands.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOST029  
About • Received ※ 07 June 2022 — Revised ※ 13 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 24 June 2022
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THPOST030 Laser Instrumentation and Insertion Device Measurement System undulator, laser, detector, controls 2513
 
  • R. Khullar, S.M. Khan, G. Mishra
    Devi Ahilya University, Indore, India
  • M. Gehlot
    MAX IV Laboratory, Lund University, Lund, Sweden
  • H. Jeevakhan
    NITTTR, Bhopal, India
 
  In this paper, we discuss the Hall probe, pulsed wire and stretched wire magnetic measurement systems indigenously developed and installed at the university laboratory at Devi Ahilya Vishwa Vidyalaya, Indore, India. The laser instrumentation such as position measuring detector, laser scanning micrometre, Wollaston interferometer and Michelson interferometer improves the Hall probe sledge alignment and magnet alignment in the undulator thus improves magnet measurement accuracy. The salient features with design specifics of the laser instrumentation along with magnetic measurement system parameters are described with context to some prototype undulators designed and developed in the laboratory.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOST030  
About • Received ※ 04 June 2022 — Revised ※ 13 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 24 June 2022
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THPOST045 Temperature Dependent Effects on RF Surface Resistivity cavity, cryogenics, electron, operation 2540
 
  • G.E. Lawler, A. Fukasawa, N. Majernik, J.B. Rosenzweig
    UCLA, Los Angeles, California, USA
 
  Funding: This work was supported by DOE Contract DE-SC0020409
A promising future for linear accelerators such as compact free electron lasers and electron positron colliders is higher gradient RF cavities enabled by cryogenic temperature operation. Breakdown rates have been shown empirically to be significantly reduced at low temperatures allowing for higher gradient. The surface physics associated with this observation is complicated and there many remain questions as to the exact phenomena responsible. One major figure of merit that can better inform the theory of breakdown is the RF surface resistivity which can be used to compute for example the RF pulse heating during operation. We then use techniques developed for previous Xband and Sband low power surface resistivity measurement by way of temperature dependent quality factor measurements to study Cband cavities. We first present a review of low temperature effects that may be responsible for the change in surface resistivity at low temperature. We then explain some of the initial measurements of these low power RF quality factor tests and compare them to a review some of the physical phenomena that could determine the low temperature surface effects.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOST045  
About • Received ※ 08 June 2022 — Revised ※ 16 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 20 June 2022
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THPOPT015 The Design of the Full Energy Beam Exploitation (FEBE) Beamline on CLARA laser, electron, diagnostics, FEL 2594
 
  • A.R. Bainbridge, D. Angal-Kalinin, J.K. Jones, T.H. Pacey, Y.M. Saveliev, E.W. Snedden
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
 
  The CLARA facility at Daresbury Laboratory was orig-inally designed for the study of novel FEL physics utilis-ing high-quality electron bunches at up to 250 MeV/c. To maximise the exploitation of the accelerator complex, a dedicated full energy beam exploitation (FEBE) beam-line has been designed and is currently being installed in a separate vault on the CLARA accelerator. FEBE will allow the use of high charge (up to 250 pC), moderate energy (up to 250 MeV), electron bunches for a wide variety of accelerator applications critical to ongoing accelerator development in the UK and international communities. The facility consists of a shielded enclo-sure, accessible during beam running in CLARA, with two very large experimental chambers compatible with a wide range of experimental proposals. High-power laser beams (up to 100 TW) will be available for electron-beam interactions in the first chamber, and there are concrete plans for a wide variety of advanced diagnostics (includ-ing a high-field permanent magnet spectrometer and dielectric longitudinal streaker), essential for multiple experimental paradigms, in the second chamber. FEBE will be commissioned in 2024.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOPT015  
About • Received ※ 08 June 2022 — Revised ※ 13 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 01 July 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPOPT029 Study on the Performance Improvement of Alkali Antimonide Photocathodes for Radio Frequency Electron Guns cathode, electron, ECR, laser 2640
 
  • R. Fukuoka, K. Ezawa, Y. Koshiba, M. Washio
    Waseda University, Tokyo, Japan
  • K. Sakaue
    The University of Tokyo, Graduate School of Engineering, Bunkyo, Japan
 
  Semiconductor photocathodes such as Cs-Te and Cs-K-Sb are used as electron sources in accelerators to generate high brightness beams using radio frequency (rf) electron guns. Alkali antimonide photocathodes have a high quantum efficiency (Q.E.) of ~10%, and their excitation wavelength is in the visible light region (532 nm), so that they are expected to reduce the requirements on the optical system and increase the amount of charge compared to Cs-Te. However, alkali antimonide photocathodes have a short lifetime and degrade under poor vacuum conditions, so it is essential to improve durability by protective film coatings. Therefore, we are currently working on the fabrication of high Q.E. alkali antimonide photocathodes that can withstand the Q.E. reduction during coating. In this presentation, we will report the results of comparison between the fabricated alkali antimonide photocathode and Cs-Te photocathode, and future prospects.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOPT029  
About • Received ※ 08 June 2022 — Revised ※ 13 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 09 July 2022
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THPOPT031 SUNDAE1: A Liquid Helium Vertical Test-Stand for 2m Long Superconducting Undulator Coils undulator, FEL, photon, power-supply 2646
 
  • B. Marchetti, S. Abeghyan, J.E. Baader, S. Casalbuoni, M. Di Felice, U. Englisch, V. Grattoni, D. La Civita, M. Vannoni, M. Yakopov, P. Ziolkowski
    EuXFEL, Schenefeld, Germany
  • S. Barbanotti, H.-J. Eckoldt, A. Hauberg, K. Jensch, S. Lederer, L. Lilje, R. Ramalingam, T. Schnautz, R. Zimmermann
    DESY, Hamburg, Germany
  • A.W. Grau
    KIT, Karlsruhe, Germany
 
  Superconducting Undulators (SCUs) can produce higher photon flux and cover a wider photon energy range compared to permanent magnet undulators (PMUs) with the same vacuum gap and period length. To build the know-how to implement superconducting undulators for future upgrades of the European XFEL facility, two magnetic measurement test stands named SUNDAE 1 and 2 (Superconducting UNDulAtor Experiment) are being developed. SUNDAE1 will facilitate research and development on magnet design thanks to the possibility of training new SCU coils and characterizing their magnetic field. The experimental setup will allow the characterization of magnets up to 2m in length. These magnets will be immersed in a Helium bath at 2K or 4K temperature. In this article, we describe the experimental setup and highlight its expected performances.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOPT031  
About • Received ※ 03 June 2022 — Revised ※ 17 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 17 June 2022
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THPOPT032 SUNDAE2 at EuXFEL: A Test Stand to Characterize the Magnetic Field of Superconducting Undulators undulator, vacuum, FEL, laser 2649
 
  • J.E. Baader, S. Abeghyan, S. Casalbuoni, D. La Civita, B. Marchetti, M. Yakopov, P. Ziolkowski
    EuXFEL, Schenefeld, Germany
  • H.-J. Eckoldt, A. Hauberg, S. Lederer, L. Lilje, T. Wohlenberg, R. Zimmermann
    DESY, Hamburg, Germany
  • A.W. Grau
    KIT, Eggenstein-Leopoldshafen, Germany
 
  European XFEL foresees a superconducting undulator (SCU) afterburner in the SASE2 hard X-ray beamline. It consists of six 5m-long undulator modules with a 5mm vacuum gap, where each module contains two 2m-long coils and one phase shifter. Prior to installation, the magnetic field must be mapped appropriately. Two magnetic measurement test stands named SUNDAE 1 and 2 (Superconducting UNDulAtor Experiment) are being developed at European XFEL. While SUNDAE1 will be a vertical test stand to measure SCU coils up to two meters with Hall probes in a liquid or superfluid helium bath, SUNDAE2 will measure the SCU coils assembled in the final cryostat. This contribution presents the development status of SUNDAE2 and its main requirements.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOPT032  
About • Received ※ 07 June 2022 — Revised ※ 13 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 28 June 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPOPT034 Controlled Degradation of a Ag Photocathode by Exposure to Multiple Gases cathode, electron, emittance, factory 2657
 
  • L.A.J. Soomary, C.P. Welsch
    The University of Liverpool, Liverpool, United Kingdom
  • L.B. Jones, T.C.Q. Noakes, C.P. Welsch
    Cockcroft Institute, Warrington, Cheshire, United Kingdom
  • L.B. Jones, T.C.Q. Noakes
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
 
  Funding: STFC Doctoral Training Studentship
The search for high performance photocathode electron sources is a priority in the accelerator science community. The surface characteristics of a photocathode define many important factors of the photoemission process including the work function, the intrinsic emittance and the quantum efficiency of the photocathode. These factors in turn define the ultimate electron beam quality, which is measurable as normalised emittance, brightness and energy spread. Strategies for improving these parameters vary, but understanding and influencing the relevant cathode surface physics which underpin these attributes is a primary focus for the community*. We present performance data under illumination at 266 nm for Ag (100) single-crystal cathode and a Ag polycrystalline cathode after progressive exposure to O2, CO2, CO and N2 using our TESS** instrument both at room and cryogenic temperatures. Crucially the data shows the effect of progressive degradation*** in the photocathode performance as a consequence of exposure to controlled levels of O2 and that exposing an oxidized Ag surface to CO can drive partial QE recovery.
*K.L. Jensen; Appl. Phys. Lett. 89, 224103 (2006);
**L.B. Jones et al.; Proc. FEL ’13, TUPPS033, 290-293;
***N. Chanlek et al.; J. Phys. D: Appl. Phys. (2014) 47, 055110;
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOPT034  
About • Received ※ 07 June 2022 — Revised ※ 10 June 2022 — Accepted ※ 14 June 2022 — Issue date ※ 10 July 2022
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THPOPT045 OPAL Simulations of the MESA Injection System simulation, solenoid, electron, quadrupole 2697
 
  • S. Friederich
    IKP, Mainz, Germany
  • K. Aulenbacher
    HIM, Mainz, Germany
  • K. Aulenbacher
    GSI, Darmstadt, Germany
  • K. Aulenbacher, C.P. Stoll
    KPH, Mainz, Germany
 
  Funding: This work is supported by the DFG excellence initiative PRISMA+.
The MESA injection system will produce the spin-polarized electron beam for the upcoming accelerator MESA in Germany. The photoemission electron source (STEAM) will deliver 150 uA of spin-polarized electrons from GaAs-based photocathodes for the P2 experiment. Afterwards the low-energy beam transportation system (MELBA) can rotate the spin using two Wien filters and a solenoid for polarization measurements and to compensate for the spin precession in MESA. A chopper and buncher system prepares the phase space for the first acceleration in the normal-conducting pre-booster MAMBO. First OPAL simulation results of MELBA were presented at IPAC’21. Meanwhile these simulations have been extended by a 270-degree-bending alpha magnet as well as the electrostatic and magnetostatic fieldmaps of the Wien filters. Furthermore the fieldmaps of the 4 modules of the pre-accelerator MAMBO have been implemented. Hence, the complete MESA injection system could be simulated in OPAL and the results will be shown.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOPT045  
About • Received ※ 30 May 2022 — Revised ※ 14 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 05 July 2022
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THPOPT063 Design of Scilab Xcos Simulation Model for Pulsed Wire Method Data Analyses undulator, electron, simulation, radiation 2741
 
  • H. Jeevakhan
    NITTTR, Bhopal, India
  • S.M. Khan, G. Mishra
    Devi Ahilya University, Indore, India
 
  Pulsed wire method (PWM)is used for undulator characterisation. Scilab Xcos simulation model is designed for the analyses of data obtained by PWM. The data obtained from PWM is given as input to the model and its output gives the magnetic field of the undulator. Scilab Xcos model can also be utilized for determining the phase error of the undulator.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOPT063  
About • Received ※ 07 June 2022 — Revised ※ 10 June 2022 — Accepted ※ 14 June 2022 — Issue date ※ 09 July 2022
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THPOTK003 Optimization of Mass Resolution Parameters Combined with Ion Cooler Performance rfq, emittance, ion-source, simulation 2770
 
  • M. Cavenago, C. Baltador, L. Bellan, M. Comunian, E. Fagotti, A. Galatà, M. Maggiore, A. Pisent, C.R. Roncolato, M. Rossignoli, A. Ruzzon
    INFN/LNL, Legnaro (PD), Italy
  • G. Maero, M. Romé
    Universita’ degli Studi di Milano e INFN, Milano, Italy
  • V. Variale
    INFN-Bari, Bari, Italy
 
  High mass resolution spectrometers (HRMS) for separation of exotic ion species in nuclear physics experiment request a low emittance and small energy spread (with D E the peak-to-peak value, and sE the rms value) of the input beam, so that ion cooler devices, as a Radio Frequency Quadrupole Coolers (RFQC), are typically envisioned. The SPES (Selective Production of Exotic Species) project at LNL requests M/(D M) about 20000, rms normalized emittance in the order of 2 nm, and for 160 keV ions, spread sE about 1 eV. Typical limits of RFQC[*] and HRMS[**] performances are discussed, and relevant formulas are implemented in easy reference tools. The necessary collisional data are reviewed, in particular for Cs+ against He gas, whose pressure ranges from 2 to 9 Pa; status of Milan test bench is briefly updated. Practical consideration on gas pumping, voltage stability and magnet design are also included.
[*] Cavenago et al. Optimization of ion transport in a combined RFQ Cooler …, in ICIS 2021 (in press)
[**] M. Comunian et al. p. 3252 in proceedings IPAC2018 doi:10.18429/JACoW-IPAC2018-THPAK021
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK003  
About • Received ※ 06 June 2022 — Revised ※ 13 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 01 July 2022
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THPOTK020 Recent Experience from the Large-Scale Deployment of Power Converters with Magnet Energy Recovery operation, controls, quadrupole, MMI 2809
 
  • K.D. Papastergiou, G. Le Godec, V. Montabonnet
    CERN, Meyrin, Switzerland
 
  A new powering solution was deployed at CERN for transfer lines in the injector complex as part of the LHC injectors upgrade. The new powering uses regenerative power converters to recycle the magnet energy between physics operations. This work gives an overview of the developed technology, the way it is used in the accelerators complex and some results of first period of operation with beam.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK020  
About • Received ※ 03 June 2022 — Revised ※ 11 June 2022 — Accepted ※ 25 June 2022 — Issue date ※ 28 June 2022
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THPOTK022 Cryogenic Infrastructure for the Mainz Energy-Recovering Superconducting Accelerator (MESA) cryogenics, target, cryomodule, SRF 2813
 
  • T. Stengler, K. Aulenbacher, F. Hug, P.S. Plattner, D. Simon
    KPH, Mainz, Germany
 
  Funding: Work supported by the German Research Foundation (DFG) under the Cluster of Excellence "PRISMA+" EXC 2118/2019
The "Mainz Energy-Recovering Superconducting Accelerator" (MESA), currently under construction at the Institute of Nuclear Physics, Johannes Gutenberg University Mainz, Germany, requires a cryogenic infrastructure for its superconducting components. Prior to the start of the project, a helium liquefier was purchased that is capable of supplying the existing infrastructure of the Institute for Nuclear Physics, as well as the SRF test facility of the Helmholtz Institute. The liquefier has already been purchased in such a way that nitrogen pre-cooling can be integrated and can be upgraded for the operation of MESA. In addition to the superconducting accelerator modules, all components of the P2 experiment, i.e. solenoid, target and polarimeter (hydromoller), must also be supplied with liquid helium. Therefore, besides the upgrade of the liquefier, it is necessary to extend the system with a dedicated cryogenic supply for the P2 target. This paper presents the current status of the cryogenic supply of the MESA accelerator, the future modifications and additions.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK022  
About • Received ※ 07 June 2022 — Revised ※ 13 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 06 July 2022
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THPOTK023 Ferrite Specification for the Mu2e 300 kHz and 4.4 MHz AC Dipole Magnets proton, dipole, electron, target 2816
 
  • K.P. Harrig, E. Prebys
    UCD, Davis, California, USA
  • L. Elementi, C.C. Jensen, H. Pfeffer, D.A. Still, I. Terechkine, S.J. Werkema, M. Wong
    Fermilab, Batavia, Illinois, USA
 
  Funding: Work supported by by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the U.S. Department of Energy, Office of Science, in addition to grant DE-SC0019254.
The Mu2e experiment at Fermilab will measure the rate for neutrinoless-conversion of negative muons into electrons with never-before-seen precision. This experiment will use a pulsed 8 GeV proton beam with pulses separated by 1.7 µs. To suppress beam induced backgrounds to this process, a set of dipoles operating at 300 kHz and 4.4 MHz have been developed that will reduce the fraction of out-of-time protons at the level of 1E-10 or less. Selection of magnetic ferrite material for construction must be carefully considered given the high repetition rate and duty cycle that can lead to excess heating in conventional magnetic material. A model of the electromagnetic and thermal properties of candidate ferrite materials has been constructed. Magnetic permeability, inductance, and power loss were measured at the two operating frequencies in toroidal ferrite samples as well as in the ferrites from which prototype magnets were built. Additionally, the outgassing rates of the ferrite material was measured to determine vacuum compatibility. The outcome of this work is a detailed specification of the electrical and mechanical details of the ferrite material required for this application.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK023  
About • Received ※ 30 May 2022 — Revised ※ 11 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 23 June 2022
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THPOTK026 Development and Test of a Program for Automatic Conditioning of Room Temperature Cavities cavity, rfq, interface, software 2823
 
  • K. Kümpel, M. Märcz, H. Podlech, A. Rüffer, C. Wagner, S.R. Wagner
    IAP, Frankfurt am Main, Germany
  • H. Podlech
    HFHF, Frankfurt am Main, Germany
 
  The conditioning of room temperature cavities is a time-consuming process that can take several weeks and requires the supervision of experienced experimenters. To simplify this process for future cavities, a program is currently being developed at the IAP Frankfurt that will simplify the experimenter’s work and eventually take it over completely. This paper describes the basic setup of the program so far, as well as the tests performed on different cavities so far. In addition, an outlook for the next development steps and their application is given.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK026  
About • Received ※ 08 June 2022 — Revised ※ 13 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 16 June 2022
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THPOTK032 A Vacuum System for the Milliampere Booster cavity, vacuum, simulation, linac 2833
 
  • R.G. Heine, C.L. Lorey
    KPH, Mainz, Germany
 
  The Milliampere Booster (MAMBO) is the injector linac for the Mainz Energy-recovering Superconducting Accelerator MESA. MESA is a multi-turn energy recovery linac with beam energies in the 100 MeV regime currently designed and built at Institut für Kernphysik (KPH) of Johannes Gutenberg-Universität Mainz. The main accelerator consists of two superconducting Rossendorf type modules, while the injector MAMBO relies on normal conducting technolgy. The MAMBO RF cavities are bi-periodic pi/2 structures that are about 2m long, each. In this paper we present the results of Molflow+ simulations of several setups of the vacuum system for MAMBO that differ in number of pumps, pumping speed and diameter of the pumping ports that are connected to the DN40 beam pipe.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK032  
About • Received ※ 07 June 2022 — Revised ※ 13 June 2022 — Accepted ※ 14 June 2022 — Issue date ※ 24 June 2022
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THPOTK036 Determination of Pumping and Dynamic Vacuum Properties of Conductive Quaternary Alloy of TiZrVAg Non-Evaporable Getter. vacuum, photon, electron, site 2843
 
  • R. Valizadeh, A.N. Hannah, O.B. Malyshev
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
  • G.Y. Hsiung
    NSRRC, Hsinchu, Taiwan
  • J.M. O’Callaghan Castella
    Universitat Politécnica de Catalunya, Barcelona, Spain
  • M. Pont, N.D. Tagdulang
    ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain
 
  Non Evaporable Getter (NEG) coating has been employed extensively in the particle accelerator especially where the vacuum conductance of the vessel is severely restricted and ultra-high vacuum condition is required. NEG coating will significantly reduce the outgassing rate and provides active pumping surface for H2, CO and CO2. In addition, it has been proven that NEG coated surfaces have a very low secondary electron yield, as well as low photon and electron stimulated desorption yields. However, the existing NEG film increases the RF surface resistance of the beam pipe. In order to increase NEG coating conductivity, at ASTeC, in the past several years, the alternative NEG com-position have been studied by adding more conductive element such as Cu, Au, Al and Ag. In this study, we report on the photon stimulated desorption, activation temperature and surface resistance from room temperature to cryogenic temperature for a new NEG quaternary alloy of TiVZrAg as function of the film composition.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK036  
About • Received ※ 07 June 2022 — Revised ※ 11 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 01 July 2022
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THPOTK037 Measurement of the Photon Stimulated Desorption for Various Vacuum Tubes at a Beam Line of TLS photon, vacuum, radiation, synchrotron 2847
 
  • G.Y. Hsiung, C.M. Cheng
    NSRRC, Hsinchu, Taiwan
  • R. Valizadeh
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
 
  For most light sources, the synchrotron radiation (SR) hit on the beam ducts or absorbers results in higher pressure rise and the consequent higher radiation level through the commissioning stage. Various surface treatments, e.g. chemical cleaning, oil-free machining, NEG-coating, etc., for the beam ducts or absorbers have been developed worldwide for mitigating the yield of Photon Stimulated Desorption (PSD). A beam line, BL19B, of 1.5 GeV Taiwan Light Source (TLS) has been modified to measure the PSD-yield of the vacuum tubes. The white light of BL19B covers the critical length at 2.14 keV is suitable for generating higher yield of the photo-electrons (PEY) and the consequent PSD-yield to be measured can be resolved wide range of 10-2 ~ 10-7 molecules/photon. The PSD-outgas, measured by RGA, contains the typical H2, CO, CO2, hydrocarbons, and Kr from NEG-coating, alcohol from ethanol machined surface, in some cases. The effect of beam-cleaning reflects the PSD-molecules generated from the SR-irradiated surface. The comparison of the PSD for the various vacuum tubes will be described in this paper.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK037  
About • Received ※ 08 June 2022 — Revised ※ 15 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 08 July 2022
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THPOTK038 Electron Stimulated Desorption From Titanium Tube electron, vacuum, radiation, photon 2850
 
  • O.B. Malyshev, R. Valizadeh
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
 
  Titanium is one of material that used for production of accelerator vacuum chamber and components. In this paper we report the results of vacuum properties evaluation measurements of titanium vacuum chamber. The sample was produced from 40-mm inner diameter tube made of titanium and equipped with CF40 flanges at both ends. The electron stimulated desorption (ESD) was measured after 24-h bakeout to 80, 150, 180 and 250 oC. H2 and CO initial sticking probabilities were measured after bakeout before the ESD measurements. After ESD measurements, the initial H2 and CO sticking probabilities were measured again together with CO sorption capacity. These measurements provide the results for ESD as a function of electron dose baked to different temperatures and demonstrate the efficiency of electron stimulated activation of titanium vacuum chamber.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK038  
About • Received ※ 25 May 2022 — Revised ※ 12 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 17 June 2022
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THPOTK039 The Effect of Activation Duration on the Performance of Non-Evaporable Getter Coatings vacuum, injection, ECR, target 2854
 
  • E.A. Marshall, O.B. Malyshev, R. Valizadeh
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
 
  Non-evaporable getter (NEG) coatings can be activated at temperatures as low as 140°C. However, better pumping properties are achieved using higher temperatures, between 150-300 °C. This paper investigates whether using an increased activation duration can improve the NEG properties obtained using lower activation temperatures, and so decrease the energy and temperature requirement. This could allow a greater range of materials to be used in particle accelerator systems. Our findings have shown that increasing activation duration from 24 hrs to 1 week at 160 °C produces an improvement in the NEG pumping properties.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK039  
About • Received ※ 01 June 2022 — Accepted ※ 10 June 2022 — Issue date ※ 17 June 2022  
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THPOTK049 Irradiation of Low-Z Carbon-Based Materials with 440 GeV/c Proton Beam for High Energy & Intensity Beam Absorbers: The CERN HiRadMat-56-HED Experiment target, proton, operation, simulation 2883
 
  • P. Andreu Muñoz, M. Calviani, N. Charitonidis, A. Cherif, E.M. Farina, A.M. Krainer, A. Lechner, J. Maestre, F.-X. Nuiry, R. Seidenbinder, C. Torregrosa
    CERN, Meyrin, Switzerland
  • P. Simon
    TU Darmstadt, Darmstadt, Germany
 
  The beam stored energy and the peak intensity of CERN Large Hadron Collider (LHC) will grow in the next few years. The former will increase from the 320 MJ values of Run2 (2015-2018) to almost 540 MJ during Run3 (2022 onwards) and 680 MJ during the HL-LHC era putting stringent requirements on beam intercepting devices, such as absorbers and dumps. The HiRadMat-56-HED (High-Energy Dumps) experiment performed in Autumn 2021 executed at CERN HiRadMat facility employed the Super Proton Synchrotron accelerator (SPS) 440 GeV/c proton beam to impact different low-density carbon-based materials targets to assess their performance to these higher energy beam conditions. The study focused on advanced grades of graphitic materials, including isostatic graphite, carbon-fiber reinforced carbon and carbon-SiC materials in addition to flexible expanded graphite. Some of them specifically tailored in collaboration with industry to very specific properties. The objectives of this experiment are: (i) to assess the performance of existing and potentially suitable advanced materials for the currently operating LHC beam dumps and (ii) to study alternative materials for the HL-LHC main dump or for the Future Circular Collider dump systems. The contribution will detail the R&D phase during design, the execution of the experiment, the pre-irradiation tests as well as the first post irradiation examination of the target materials. Lessons learnt and impact on operational devices will also be drawn.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK049  
About • Received ※ 03 June 2022 — Revised ※ 15 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 04 July 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPOTK050 CFD Studies of the Convective Heat Transfer Coefficients and Pressure Drops in Geometries Applied to Water Cooling Channels of the Crotch Absorbers of ALBA Synchrotron Light Source simulation, synchrotron, GUI, storage-ring 2887
 
  • S. Grozavu, G.A. Raush
    ESEIAAT, Terrassa, Spain
  • J.J. Casas, C. Colldelram, M. Quispe
    ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain
 
  Currently, the storage ring vacuum chambers of ALBA are protected by 156 crotch absorbers made of copper and Glidcop. After more than 10 years of operation as a third-generation light source, the ALBA II project arose, aiming to transform this infrastructure into a fourth-generation synchrotron. This introduces new challenges in terms of the thermal and mechanical design of the future absorbers. The absorbers’ cooling channels consist of a set of 8-mm-diameter holes parallel to each other and drilled into the body of the absorbers. In each hole, there is a 6x1 mm stainless steel concentric inner tube coiled in spiral wires, whose aim is to enhance the heat transfer. The convective heat transfer coefficients used for the original design of the absorbers come from experimental correlations from the literature, and are applied as a global value for the whole system. In this work, Heat Transfer-Computational Fluid Dynamics (HT-CFD) studies of the convective heat transfer coefficients and pressure gradients in three different cooling channel geometries are carried out, aiming at leading the way of designing the cooling systems toward the CFD simulations rather than applying global experimental values. This information will be useful for the sizing of the new absorbers for the ALBA II project.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK050  
About • Received ※ 08 June 2022 — Revised ※ 11 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 16 June 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPOTK051 Corrosion of Copper Components in the Deionized Water Cooling System of ALBA Synchrotron Light Source: Current Research Status and Challenges operation, synchrotron, cavity, radio-frequency 2891
 
  • M. Quispe, E. Ayas, J.J. Casas, C. Colldelram, Ll. Fuentes, J. Iglesias
    ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain
  • A. Garcia
    La Romanica, Barberà del Vallès, Sabadell, Spain
 
  Currently, the ALBA Synchrotron Light Source is carrying out studies on corrosion in copper components of the deionized water cooling circuit. The preliminary studies, based on Scanning Electron Microscopy (SEM), Energy Dispersive X-Ray Spectroscopy (EDS), and X-Ray Diffraction (XRD) have shown the presence of intergranular, pitting, and generalized corrosion in the analyzed copper samples. The purpose of this paper is to present new advances in the field of this research, such as: the study of the influence of low velocity water flow in the cooling circuit on the current high dissolved oxygen content (> 6500 ppb), the results of corrosion products found in the cooling circuit, the description of the improper operation of the cooling circuit as a closed loop, and FEA studies of copper components in order to redefine the water flow velocity design criteria to values lower than 3 m/s and thus minimize corrosion by erosion. Finally, in order to attenuate the corrosion rate, preventive solutions are presented such as the viability to install an oxygen content degassing plant, new instrumentation for water quality monitorization, and installation of degassing equipment at strategic positions of the cooling circuit.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK051  
About • Received ※ 07 June 2022 — Accepted ※ 14 June 2022 — Issue date ※ 17 June 2022  
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPOTK053 Foiled Again: Solid-State Sample Delivery for High Repetition Rate XFELs laser, target, FEL, controls 2899
 
  • N. Majernik, N. Inzunza, P. Manwani, J.B. Rosenzweig
    UCLA, Los Angeles, California, USA
  • R.B. Agustsson, A. Moro
    RadiaBeam, Santa Monica, California, USA
  • R. Ash, N.B. Welke
    UW-Madison/PD, Madison, Wisconsin, USA
  • U. Bergmann, A. Halavanau, C. Pellegrini
    SLAC, Menlo Park, California, USA
 
  Funding: Department of Energy DE-SC0009914 and DE-AC02-76SF00515
XFELs today are capable of delivering high intensity pulse trains of x-rays with up-to MHz to sub-GHz frequency. These x-rays, when focused, can ablate a sample in a single shot, requiring the sample material to be replaced in time for the next shot. For some applications, especially serial crystallography, the sample may be renewed as a dilute solution in a high speed jet. Here, we describe the development and characterization of a system to deliver solid state sample material to an XFEL nanofocus. The first application of this system will be an x-ray laser oscillator operating at the copper Kα line with a ~30 ns cavity.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK053  
About • Received ※ 06 June 2022 — Revised ※ 15 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 02 July 2022
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THPOTK057 ESS RFQ Experimental Modal Analysis rfq, damping, software, cavity 2907
 
  • E. Trachanas, A. Bignami, N. Gazis, B. Jones
    ESS, Lund, Sweden
 
  The European Spallation Source-ESS, which is currently under construction and commissioning at Lund, Sweden is a neutron source that consists of a 2 GeV linear accelerator (LINAC) accelerating a proton beam to a solid Tungsten (W) target. The proton beam is produced by the Ion Source (ISRC) and transported through the Low Energy Beam Transport (LEBT) to the Radio Frequency Quadrupole (RFQ) that will then focus, bunch and accelerate it to 3.6 MeV. The RFQ beam commissioning started in October 2021, following the RF conditioning phase in summer 2021. This current work presents an experimental modal analysis performed on RFQ including the comparative analysis with the modal finite element simulation using the ANSYS software suite. Measurements were performed using accelerometer sensors connected to a data acquisition system excited with an impact hammer. Geophones were used in parallel to the modal measurements in order to monitor the seismic background of the accelerator tunnel. Acquired data were post-processed and analysed with dedicated software, juxtaposed with simulated results in order to determine the resonance frequencies, structural deformation patterns (mode shapes) and error margin between experimental and simulated results.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK057  
About • Received ※ 07 June 2022 — Revised ※ 11 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 17 June 2022
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THPOTK058 CERN’s East Experimental Area: A New Modern Physics Facility target, MMI, operation, secondary-beams 2911
 
  • S. Evrard, D. Banerjee, J. Bernhard, F. Carvalho, S. Danzeca, M. Lazzaroni, B. Rae, G. Romagnoli
    CERN, Meyrin, Switzerland
 
  CERN’s East Area has hosted a variety of fixed-target experiments since the 1950s, using four beamlines from the Proton Synchrotron (PS). Over the past 4 years, the experimental area - CERN’s second largest - has undergone a complete makeover. New instrumentation and beamline configuration have improved the precision of data collection, and new magnets and power convertors have drastically reduced the area’s energy consumption. This article will summarize the major challenges encountered for the design of the renovated beamlines and for the preparation and test of the components. The infrastructure was carefully fitted resulting in a very smooth beam commissioning, the details of which will also be presented along with the restart of physics in the second half of 2021. With the return of the beams in the accelerator complex, the East Area’s experiments have taken physics measurements again and the facility’s central role in the modern physics landscape has been restored.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK058  
About • Received ※ 08 June 2022 — Revised ※ 12 June 2022 — Accepted ※ 14 June 2022 — Issue date ※ 05 July 2022
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THPOTK061 Machine Learning Approach to Temporal Pulse Shaping for the Photoinjector Laser at CLARA laser, network, target, electron 2917
 
  • A.E. Pollard, D.J. Dunning, W.A. Okell, E.W. Snedden
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
 
  The temporal profile of the electron bunch is of critical importance in accelerator areas such as free-electron lasers and novel acceleration. In FELs, it strongly influences factors including efficiency and the profile of the photon pulse generated for user experiments, while in novel acceleration techniques it contributes to enhanced interaction of the witness beam with the driving electric field. Work is in progress at the CLARA facility at Daresbury Laboratory on temporal shaping of the ultraviolet photoinjector laser, using a fused-silica acousto-optic modulator. Generating a user-defined (programmable) time-domain target profile requires finding the corresponding spectral phase configuration of the shaper; this is a non-trivial problem for complex pulse shapes. Physically informed machine learning models have shown great promise in learning complex relationships in physical systems, and so we apply machine learning techniques here to learn the relationships between the spectral phase and the target temporal intensity profiles. Our machine learning model extends the range of available photoinjector laser pulse shapes by allowing users to achieve physically realisable configurations for arbitrary temporal pulse shapes.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK061  
About • Received ※ 30 May 2022 — Revised ※ 15 June 2022 — Accepted ※ 01 July 2022 — Issue date ※ 03 July 2022
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THPOTK062 Thermal Modeling and Benchmarking of Crystalline Laser Amplifiers laser, simulation, software, ECR 2921
 
  • D.T. Abell, D.L. Bruhwiler, P. Moeller, R. Nagler, B. Nash, I.V. Pogorelov
    RadiaSoft LLC, Boulder, Colorado, USA
  • Q. Chen, C.G.R. Geddes, C. Tóth, J. van Tilborg
    LBNL, Berkeley, USA
  • N.B. Goldring
    STATE33 Inc., Portland, Oregon, USA
 
  Funding: This work is supported by the US Department of Energy, Office of High Energy Physics under Award Numbers DE-SC0020931 and DE-AC02-05CH11231.
Ti:sapphire crystals constitute the lasing medium of a class of lasers valued for their wide tunability and ultra-short, ultra-high intensity pulses. When operated at high power and high repetition rate (1kHz), such lasers experience multiple effects that can degrade performance. In particular, thermal gradients induce a spatial variation in the index of refraction, hence thermal lensing*. Using the open-source finite-element code FEniCS***, we solve the relevant partial differential equations to obtain a quantitative measure of the disruptive effects of thermal gradients on beam quality. We present thermal simulations of a pump laser illuminating a Ti:sapphire crystal. From these simulations we identify the radial variation in the refractive index, and hence the extent of thermal lensing. In addition, we present analytic models used to estimate the effect of thermal gradients on beam quality. This work generalizes to other types of crystal amplifiers.
* S. Cho, et al., Appl. Phys. Express, 11:092701, 2018.
** M. Born & E. Wolf, Principles of Optics, Cambridge Univ. Press, 1980.
*** The FEniCS computing platform, https://fenicsproject.org
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK062  
About • Received ※ 13 June 2022 — Revised ※ 10 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 17 June 2022
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THPOTK063 Open Source Software to Simulate Ti:Sapphire Amplifiers laser, simulation, optics, photon 2925
 
  • D.L. Bruhwiler, D.T. Abell, B. Nash
    RadiaSoft LLC, Boulder, Colorado, USA
  • Q. Chen, C.G.R. Geddes, C. Tóth, J. van Tilborg
    LBNL, Berkeley, USA
  • N.B. Goldring
    STATE33 Inc., Portland, Oregon, USA
 
  Funding: This work is supported by the US Department of Energy, Office of High Energy Physics under Award Numbers DE-SC0020931 and DE-AC02-05CH11231.
The design of next-generation PW-scale fs laser systems, including scaling to kHz rates and development of new laser gain media for efficiency, will require parallel multiphysics simulations with realistic errors and nonlinear optimization. There is currently a lack of broadly available modeling software that self-consistently captures the required physics of gain, thermal loading and lensing, spectral shaping, and other effects required to quantitatively design such lasers.* We present initial work towards an integrated multiphysics capability for modeling pulse amplification in Ti:Sa lasers. All components of the software suite are open source. The Synchrotron Radiation Workshop (SRW)** is being used for physical optics, together with Python utilities. The simulations are being validated against experiments.
* R. Falcone et al., Brightest Light Initiative Workshop Report (2019).
** https://github.com/ochubar/srw
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK063  
About • Received ※ 14 June 2022 — Revised ※ 14 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 16 June 2022
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THPOMS029 Testing the Properties of Beam-Dose Monitors for VHEE-FLASH Radiation Therapy detector, electron, radiation, real-time 3018
 
  • J.J. Bateman, P. Burrows, L.A. Dyks
    JAI, Oxford, United Kingdom
  • R. Corsini, M. Dosanjh, W. Farabolini, A. Gerbershagen, N. Heracleous, P. Korysko, S. Morales Vigo, V. Rieker, B. Salvachúa, M. Silari, G. Zorloni
    CERN, Meyrin, Switzerland
  • F. Murtas
    LNF-INFN, Frascati, Italy
 
  Very High Energy Electrons (VHEE) of 50 - 250 MeV are an attractive choice for FLASH radiation therapy (RT). Before VHEE-FLASH RT can be considered for clinical use, a reliable dosimetric and beam monitoring system needs to be developed, able to measure the dose delivered to the patient in real-time and cut off the beam in the event of a machine fault to prevent overdosing the patient. Ionisation chambers are the standard monitors in conventional RT; however, their response saturates at the high dose rates required for FLASH. Therefore, a new dosimetry method is needed that can provide reliable measurements of the delivered dose in these conditions. Experiments using 200 MeV electrons were done at the CLEAR facility at CERN to investigate the properties of detectors such as diamond beam loss detectors, GEM foil detectors, and Timepix3 ASIC chips. From the tests, the GEM foil proved to be the most promising.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOMS029  
About • Received ※ 08 June 2022 — Revised ※ 12 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 16 June 2022
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THPOMS030 Updates, Status and Experiments of CLEAR, the CERN Linear Electron Accelerator for Research electron, radiation, plasma, focusing 3022
 
  • P. Korysko
    Oxford University, Physics Department, Oxford, Oxon, United Kingdom
  • J.J. Bateman, C.S. Robertson
    JAI, Oxford, United Kingdom
  • R. Corsini, M. Dosanjh, L.A. Dyks, A. Gilardi, V. Rieker
    CERN, Meyrin, Switzerland
  • W. Farabolini
    CEA-DRF-IRFU, France
  • K.N. Sjobak
    University of Oslo, Oslo, Norway
 
  The CERN Linear Accelerator for Research (CLEAR) at CERN is a test facility using a 200 MeV electron beam. In 2020 and 2021, a few hardware upgrades were done: comparators for position measurements were added on components, the in-air experimental area was re-arranged in order to provide more space, a robotic system was built to enable remote samples manipulations for irradiation studies, the BPM reading system was optimized and the laser double-bunch system implemented to allow for a doubling of the electron bunch frequency from 1.5 GHz to 3 GHz. In the paper, we describe such improvements, we outline the experimental activities during 2021 and illustrate the diverse program for the next 4 years, including high doses’ irradiation studies for medical applications.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOMS030  
About • Received ※ 08 June 2022 — Revised ※ 15 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 28 June 2022
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THPOMS037 Ripple Pattern Formation on Silicon Carbide Surfaces by Low-Energy Ion-Beam Erosion radiation, HOM, cathode, ion-source 3045
 
  • D. Gupta, S. Aggarwal
    Kurukshetra University, Kurukshetra, India
  • R. Singhal
    Malviya Institute of Technology, Jaipur, India
  • G.R. Umapathy
    IUAC, New Delhi, India
 
  A versatile air insulated high current medium energy 200 kV Ion Accelerator has been running successfully at Ion Beam Centre, Kurukshetra University, India for carrying out multifarious experiments in material science and surface physics. Ion beam induced structures on the surfaces of semiconductors have potential applications in photonics, magnetic devices, photovoltaics, and surface-wetting tailoring etc. In this regard, silicon carbide (SiC) is a fascinating wide-band gap semiconductor for high-temperature, high-power and high-frequency applications. In the present work, fabrication of self-organized ripple patterns is carried out on the SiC surfaces using 80 keV Ar+ ions for different fluences at oblique incidence of 500. Studies demonstrate that ripple wavelength and amplitude, ordering and homogeneity of these patterns vary linearly with argon ion fluence. The ripples tend to align themselves parallel to the projection of the ion beam direction. The evolution of such surface structures is explained with the help of existing formalisms of coupling between surface topography and preferential sputtering.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOMS037  
About • Received ※ 20 May 2022 — Revised ※ 13 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 18 June 2022
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THPOMS038 Spallation Target Optimization for ADS by Monte Carlo Codes target, neutron, proton, site 3049
 
  • MumyapanM. Mumyapan, J.-S. Chai, M. Ghergherehchi, D.H. Ha, H. Namgoong
    SKKU, Suwon, Republic of Korea
 
  Accelerator Driven Systems are advanced systems for the use of Thorium as fuel, aiming to reduce nuclear waste through transmutation. The spallation target, which is responsible for producing neutrons, is one of the main parts of the ADS system. In this research, neutronic parameters of spallation targets consisting of several materials LBE, Mercury, Lead, Mercury on the cylindrical, box, and conic shapes using Monte Carlo codes (FLUKA, PHITS, MCNPX) was investigated. Energy Deposition and spallation neutron yield of spallation target with different shapes and dimensions have been calculated to optimization of the target. According to the results, the neutron yield values from MCNPX and PHITS are similar and it’s close to the experimental result. On the other hand, the error rate of the values in FLUKA is higher.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOMS038  
About • Received ※ 16 May 2022 — Revised ※ 12 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 17 June 2022
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THPOMS039 Investigation on Intermolecular Interactions in Ionic Liquids Using Accelerator-based THz Transition Radiation radiation, electron, FEM, ion-source 3053
 
  • P. Nanthanasit, S. Rimjaem
    Chiang Mai University, Chiang Mai, Thailand
  • N. Chattrapiban, P. Nimmanpipug, S. Rimjaem
    ThEP Center, Commission on Higher Education, Bangkok, Thailand
  • M. Jitvisate
    Suranaree University of Technology, Nakhon Ratchasima, Thailand
 
  Ionic liquids (ILs) are interesting material that can be used in many applications. Spectroscopic measurement using accelerator-based terahertz transition radiation (THz TR) is one of potential techniques to investigate their intermolecular interactions by observing the vibra-tional bands in the terahertz region due to TR’s excep-tional properties: coherent, broadband, and high intensi-ty. This work aims to study intermolecular interactions of ILs using the THz TR produced from an electron beam at the PBP-CMU Electron Linac Laboratory. The THz TR with the frequency range of 0.3-2.5 THz can be produced from electron beam of energy 10-25 MeV. This radiation is produced and transported to the experimental area, where it is used as the coherent and polarization selective light source for the Fourier transform infrared (FTIR) spectrometer. The absorption spectrum in the THz region of the ILs is then measured. In addition, to explain the experimental results deeply, theoretical calculations using the density functional theory are performed. In this contribution, we present the results from experiment and computational calculation that can be used together to describe the intermolecular interactions in ILs.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOMS039  
About • Received ※ 08 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 02 July 2022  
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THPOMS040 Present Status of Linear Accelerator System for Natural Rubber Vulcanization at Chiang Mai University radiation, electron, linac, shielding 3057
 
  • C. Thongbai, P. Jaikaew, E. Kongmon, S. Rimjaem, J. Saisut, P. Wongkummoon
    Chiang Mai University, Chiang Mai, Thailand
  • N. Khangrang
    Chiang Mai University, PBP Research Facility, Chiang Mai, Thailand
  • M.W. Rhodes, S. Rimjaem, J. Saisut, C. Thongbai
    ThEP Center, Commission on Higher Education, Bangkok, Thailand
 
  At the Plasma and Beam Physics (PBP) Research Fa-cility, Chiang Mai University (CMU), an electron beam accelerator system for natural rubber irradiation has been under development and is currently under the commissioning. The research project is carried out with the aim to modify an old medical linac, retired from the clinical operation, for rubber latex vulcanization and materials irradiation using electron beams. The accelerator system consists of a DC-thermionic cathode electron gun, a standing-wave RF linear accelerator, an RF system, a control system, beam diagnostic systems, and an irradia-tion system. The components were completely assembled, and the RF system was tested. The RF processing has been performed and some of the electron beam properties have been measured. This contribution presents some experimental results while developing and testing the various sub-systems of this accelerator. The present status of development and some vulcanization results will also be reported in this contribution.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOMS040  
About • Received ※ 07 June 2022 — Revised ※ 12 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 04 July 2022
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THPOMS041 Design and Parameterization of Electron Beam Irradiation System for Natural Rubber Vulcanization simulation, electron, radiation, linac 3061
 
  • P. Wongkummoon
    Chiang Mai University, PBP Research Facility, Chiang Mai, Thailand
  • N. Kangrang, S. Rimjaem, J. Saisut, C. Thongbai
    Chiang Mai University, Chiang Mai, Thailand
  • M.W. Rhodes
    IST, Chiang Mai, Thailand
 
  Electron beam irradiation is a process to modify or improve the properties of materials with less chemical residue. In natural rubber vulcanization, a proper electron absorbed dose is about 50-150 kGy. In this study, the experimental station is designed to investigate the deposition of the electron beam in natural rubber. Electron beams generated from an RF linac are used in this study. This accelerator can generate the beam with energies in the range of 1-4 MeV and an adjustable repetition rate of up to 200 Hz. We can optimize these parameters to maximize the throughput and uniformity of electron dose in the vulcanization. The simulation results from GEANT4 were used to narrow down the appropriate parameters in the experiment. In the early stage of the study, water was used as a sample instead of natural rubber. The dose distribution was obtained by placing a B3 film dosimeter under a water chamber. The water depth was varied from 0.5 to 2.0 cm. The simulation results provide the dose distribution to compare with the experimental results. In a further study, the beam irradiation in natural rubber with these optimal parameters and vulcanization tests will be performed.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOMS041  
About • Received ※ 08 June 2022 — Revised ※ 16 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 03 July 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPOMS046 Generation of Flat-Laser Compton Scattering Gamma-ray Beam in UVSOR undulator, electron, laser, simulation 3070
 
  • H. Ohgaki, K. Ali, T. Kii, H. Zen
    Kyoto University, Kyoto, Japan
  • M. Fujimoto, Y. Taira
    UVSOR, Okazaki, Japan
  • T. Hayakawa, T. Shizuma
    QST, Tokai, Japan
 
  Funding: This work is supported by JSPS KAKENHI Grant Number 21H01859. A part of this work was performed at the BL1U of UVSOR, IMS, Okazaki (IMS program 21-603).
Flat energy distribution Laser Compton scattering (F-LCS) gamma-ray beam, which has a flat distribution in the energy spectrum and the spatial distribution with a small beam size, has been developed to study an isotope selective CT Imaging application at the beamline BL1U in UVSOR. We have successfully demonstrated a three-dimensional (3D) isotope-selective CT image by using a conventional LCS gamma-ray beam[1]. However, the conventional LCS beam with a small beam size whose energy spread is narrow can’t excite a few isotopes at the same time. Therefore, we proposed the F-LCS gamma-ray beam by using the Apple-II undulator installed in BL1U in UVSOR to excite a circular motion of the electron beam. An EGS5 simulation shows that a weak magnetic field (K=0.2) can generate an F-LCS beam. The demonstration experiments have been carried out in UVSOR and the spectra of generated LCS beam with different K-values of the undulator were measured. As a result, the measured spectra agreed with the EGS5 simulation. The principle of F-LCS generation and experimental results, including the effect on the stored electron beam, will be presented at the conference.
[1] K. Ali, et. al., "Three-dimensional nondestructive isotope-selective tomographic imaging of 208Pb distribution via nuclear resonance fluorescence". Appl. Sci. 2021, 11, 3415.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOMS046  
About • Received ※ 02 June 2022 — Revised ※ 11 June 2022 — Accepted ※ 13 June 2022 — Issue date ※ 16 June 2022
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THPOMS052 Magnetic Field Shield for SC-Cavity with Thin Nb Sheet cavity, niobium, shielding, cryogenics 3090
 
  • Y. Iwashita, Y. Kuriyama
    Kyoto University, Research Reactor Institute, Osaka, Japan
  • Y. Fuwa
    JAEA/J-PARC, Tokai-mura, Japan
  • H. Tongu
    Kyoto ICR, Uji, Kyoto, Japan
 
  Funding: This work was partly supported by JSPS KAKENHI Grant Number 19K21877.
Shielding the superconducting accelerating cavity made of niobium from the weak environmental magnetic field is an important subject. Niobium is a type-II superconductor, which traps the environmental magnetic flux in the material during the superconducting transition, resulting in increase of residual resistance and heating during operation during operation. Shielding from a weak magnetic field is essential for high performance operations. A magnetic shielding method that uses the diamagnetism of superconducting materials instead of magnetic flux absorption by high magnetic permeability materials is discussed.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOMS052  
About • Received ※ 14 June 2022 — Revised ※ 15 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 18 June 2022
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THPOMS054 Beam Lines and Stations for Applied Research Based on Ion Beams Extracted from Nuclotron detector, radiation, target, diagnostics 3096
 
  • G.A. Filatov, A. Agapov, A.A. Baldin, A.V. Butenko, A.R. Galimov, S.Yu. Kolesnikov, K.N. Shipulin, A. Slivin, E. Syresin, G.N. Timoshenko, A. Tuzikov, A.S. Vorozhtsov
    JINR, Dubna, Moscow Region, Russia
  • S. Antoine, W. Beeckman, X.G. Duveau, J. Guerra-Phillips, P.J. Jehanno
    SIGMAPHI S.A., Vannes, France
  • D.V. Bobrovskiy, A.I. Chumakov
    MEPhI, Moscow, Russia
  • P.N. Chernykh, S. Osipov, E. Serenkov
    Ostec Enterprise Ltd, Moscow, Russia
  • D.G. Firsov, A.S. Kubankin, Yu.S. Kubankin
    LLC "Vacuum systems and technologies", Belgorod, Russia
  • I.L. Glebov, V.A. Luzanov
    GIRO-PROM, Dubna, Moscow Region, Russia
  • T. Kulevoy
    NRC, Moscow, Russia
  • Y.E. Titarenko
    ITEP, Moscow, Russia
 
  New beamlines and irradiation stations of the Nuclotron-based Ion Collider fAcility (NICA) are currently under construction at JINR. These facilities for applied research will provide testing on capsulated microchips (ion energy range of 150-500 MeV/n) at the Irradiation Setup for Components of Radioelectronic Apparatus (ISCRA) and space radiobiological research (ion energy range 400-1100 MeV/n) at the Setup for Investigation of Medical Biological Objects (SIMBO). In this note, the technical details of SIMBO and ISCRA stations and their beamlines are described and discussed.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOMS054  
About • Received ※ 20 May 2022 — Accepted ※ 17 June 2022 — Issue date ※ 06 July 2022  
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THPOMS056 An Overview of the Applications of MIR and THz Spectroscopy in Astrochemistry Studies detector, electron, FEL, radiation 3102
 
  • C. Suwannajak, U. Keyen, A. Leckngam, N. Tanakul
    NARIT, Chiang Mai, Thailand
  • W. Jaikla, S. Pakluea, P. Wongkummoon
    Chiang Mai University, PBP Research Facility, Chiang Mai, Thailand
  • M. Jitvisate
    Suranaree University of Technology, Nakhon Ratchasima, Thailand
  • P. Nimmanpipug, S. Rimjaem
    ThEP Center, Commission on Higher Education, Bangkok, Thailand
  • S. Pakluea, S. Rimjaem, P. Wongkummoon
    Chiang Mai University, Chiang Mai, Thailand
  • T. Phimsen
    SLRI, Nakhon Ratchasima, Thailand
 
  Interstellar complex molecules can be found in molecular clouds which are spread throughout our galaxy. Some of these molecules are thought to be the precursors of bio-molecules. Therefore, understanding the formation processes of those interstellar complex molecules is crucial to understanding the origin of the building blocks of life. There are currently more than a hundred known complex molecules discovered in interstellar clouds. However, the formation processes of those molecules are not yet well understood since they occur in very extreme conditions and very short time scale. Ultrafast spectroscopy can be applied to study those processes that occur in the time scale of femtoseconds or picoseconds. In this work, we present an overview of the applications of MIR and THz pump-probe experiments in astrochemistry studies. An experimental setup to simulate space conditions that mimic the environments where the interstellar complex molecules are formed is currently being developed at the PBP-CMU Electron Linac Laboratory. Then, we present our development plan of the experimental station and its current status.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOMS056  
About • Received ※ 08 June 2022 — Revised ※ 10 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 23 June 2022
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THPOMS057 Using Co-Moving Collisions in a Gear-Changing System to Measure Fusion Cross-Sections luminosity, neutron, collider, ECR 3105
 
  • E.A. Nissen
    JLab, Newport News, Virginia, USA
 
  Funding: Notice: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177. The U.S. Government retains a license to publish or reproduce this manuscript.
In this work we look at a possible use for a system that collides beams moving in the same direction using a gear-changing synchronization method as a means of measuring low energy phenomena, such as fusion cross sections. Depending on the energies used this process will allow for interactions for any desired charge state of the target nuclei. Earlier concepts for low energy interactions to study focused on beams crossing at an angle to give the low energy interactions, as well as general investigations of comoving collisions. This proposal would use gear-changing, a method involving two different harmonic numbers of bunches in each collider ring, to have the same types of collisions, with a luminosity equal that of a head-on machine. In this work we detail the design considerations for such a machine, leveraging experimental experience with a co-moving, gear-changing system.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOMS057  
About • Received ※ 08 June 2022 — Revised ※ 12 June 2022 — Accepted ※ 12 June 2022 — Issue date ※ 14 June 2022
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FROXGD1 A Method for Obtaining 3D Charge Density Distribution of a Self-Modulated Proton Bunch proton, plasma, wakefield, electron 3118
 
  • T. Nechaeva, P. Muggli
    MPI-P, München, Germany
  • L. Verra, G. Zevi Della Porta
    CERN, Meyrin, Switzerland
  • L. Verra
    TUM, Munich, Germany
  • L. Verra
    MPI, Muenchen, Germany
 
  The Advanced Wakefield Experiment (AWAKE) at CERN is the first plasma wakefield accelerator experiment to use a proton bunch as driver. The long bunch undergoes seeded self-modulation (SSM) in a 10 m-long plasma. SSM transforms the bunch into a train of short micro-bunches that resonantly drive high-amplitude wakefields. We use optical transition radiation (OTR) and a streak camera to obtain time-resolved images of the bunch transverse charge density distribution in a given plane. In this paper we present a method to obtain 3D images of the bunch by scanning the OTR across the entrance slit of the streak camera. Reconstruction of the 3D distribution is possible because with seeding self-modulation is reproducible*. The 3D images allow for checking the axi-symmetry of SSM and for detecting the possible presence of the non-axi-symmetric hosing instability (HI).
* F. Batsch et al., Phys. Rev. Lett. 126, 164802 (2021).
 
slides icon Slides FROXGD1 [4.026 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-FROXGD1  
About • Received ※ 20 May 2022 — Revised ※ 15 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 30 June 2022
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FROXSP2 Demonstration of Gradient Above 300 MV/m in Short Pulse Regime Using an X-Band Single-Cell Structure acceleration, accelerating-gradient, wakefield, electron 3134
 
  • J.H. Shao, D.S. Doran, G. Ha, C.-J. Jing, W. Liu, J.G. Power, C. Whiteford, E.E. Wisniewski
    ANL, Lemont, Illinois, USA
  • H.B. Chen, X. Lin, M.M. Peng, J. Shi, H. Zha
    TUB, Beijing, People’s Republic of China
  • C. Jing
    Euclid Beamlabs, Bolingbrook, USA
 
  High gradient acceleration is one of the critical technologies required by future linear colliders, free-electron lasers, and compact linac-based applications. Among decade long effort to break state-of-the-art gradient limitation of ~100 MV/m in normal conducting structures, using RF pulses shorter than 20 ns is a promising approach based on theoretic analysis and experimental observation. In this study, we demonstrated high gradient above 300 MV/m using an X-band 11.7 GHz single-cell travelling-wave structure with 6 ns FWHM RF pulses generated by a power extractor. In comparison, a scaled 11.424 GHz structure only reached below 150 MV/m driven by 30-100 ns RF pulses from a klystron with pulse compression. The experimental results and the suggested new mechanism of beam acceleration in the Breakdown Insensitive Acceleration Regime (BIAR) are presented in this manuscript.  
slides icon Slides FROXSP2 [8.998 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-FROXSP2  
About • Received ※ 11 June 2022 — Revised ※ 14 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 20 June 2022
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