MC4: Hadron Accelerators
T12: Beam Injection/Extraction and Transport
Paper Title Page
WEPOST012 Feasibility of Slow-Extracted High-Energy Ions From the CERN Proton Synchrotron for CHARM 1703
 
  • M.A. Fraser, P.A. Arrutia Sota, K. Biłko, N. Charitonidis, S. Danzeca, M. Delrieux, M. Duraffourg, N. Emriskova, L.S. Esposito, R. García Alía, A. Guerrero, O. Hans, G.I. Imesch, E.P. Johnson, G. Lerner, I. Ortega Ruiz, G. Pezzullo, D. Prelipcean, F. Ravotti, F. Roncarolo, A. Waets
    CERN, Meyrin, Switzerland
 
  The CHARM High-energy Ions for Micro Electronics Reliability Assurance (CHIMERA) working group at CERN is investigating the feasibility of delivering high energy ion beams to the CHARM facility for the study of radiation effects to electronics components engineered to operate in harsh radiation environments, such as space or high-energy accelerators. The Proton Synchrotron has the potential of delivering the required high energy and high-Z (in this case, Pb) ions for radiation tests over the relevant range of Linear Energy Transfer of ~ 10 - 40 MeV cm2/mg with a > 1 mm penetration depth in silicon, specifically for single event effect tests. This contribution summarises the working group’s progress in demonstrating the feasibility of variable energy slow extraction and over a wide range of intensities. The results of a dedicated 6 GeV/u Pb ion beam test are reported to understand the performance limitations of the beam instrumentation systems needed to characterise the beam in CHARM.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOST012  
About • Received ※ 02 June 2022 — Revised ※ 14 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 23 June 2022
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WEPOST014 Studies on Pre-Computation of SPS-to-LHC Transfer Line Corrections 1711
 
  • C. Bracco, F.M. Velotti
    CERN, Meyrin, Switzerland
 
  The injection process in the LHC gives a non-negligible contribution to the turnaround time between two consecutive physics fills. Mainly due to orbit drifts in the SPS, the steering of the SPS-to-LHC transfer lines (TL) had to be regularly performed in view of minimising injection oscillations and losses, which otherwise would trigger beam dumps. Moreover, for machine protection purposes, a maximum of twelve bunches had to be injected after any TL steering to validate the actual applied corrections. This implied at several occasions the need to interrupt a fill to steer the lines and introduced a further delay between fills. Studies were performed to evaluate the option of pre-calculating the required TL corrections based on SPS orbit measurements during the LHC magnet ramp down and the reconstruction of the beam position and angle at the SPS extraction point.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOST014  
About • Received ※ 06 June 2022 — Revised ※ 14 June 2022 — Accepted ※ 14 June 2022 — Issue date ※ 16 June 2022
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WEPOST015 Implementation of a Tune Sweep Slow Extraction with Constant Optics at MedAustron 1715
 
  • P.A. Arrutia Sota, M.A. Fraser, B. Goddard, V. Kain, F.M. Velotti
    CERN, Meyrin, Switzerland
  • P. Burrows
    JAI, Oxford, United Kingdom
  • A. De Franco
    QST Rokkasho, Aomori, Japan
  • F. Kuehteubl, M.T.F. Pivi, D.A. Prokopovich
    EBG MedAustron, Wr. Neustadt, Austria
 
  Conventional slow extraction driven by a tune sweep perturbs the optics and changes the presentation of the beam separatrix to the extraction septum during the spill. The constant optics slow extraction (COSE) technique, recently developed and deployed operationally at the CERN Super Proton Synchrotron to reduce beam loss on the extraction septum, was implemented at MedAustron to facilitate extraction with a tune sweep of operational beam quality. COSE fixes the optics of the extracted beam by scaling all machine settings with the beam rigidity following the extracted beam’s momentum. In this contribution the implementation of the COSE extraction technique is described before it is compared to the conventional tune sweep and operational betatron core driven cases using both simulations and recent measurements.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOST015  
About • Received ※ 07 June 2022 — Revised ※ 16 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 18 June 2022
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WEPOTK021 Improvement of Spill Quality for Slowly Extracted Ions at GSI-SIS18 via Transverse Emittance Exchange 2093
 
  • J. Yang, P. Forck, T. Giacomini, P.J. Niedermayer, R. Singh, S. Sorge
    GSI, Darmstadt, Germany
 
  The temporal beam stabilization of slowly extracted beams from the synchrotron within several seconds is crucial for fulfilling the demands of fix-target experiments. Results from previous investigations suggest that the transit time spread can be increased by reducing the beam emittance in the plane of extraction. Increased transit time spread is known to cut-off high frequency noise introduced by magnet power supplies. A pilot experiment was performed at SIS18 at GSI to introduce transverse emittance exchange, resulting in the circulating beam’s smaller horizontal beam size. The improvement of the spillμstructure is reported in this contribution.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOTK021  
About • Received ※ 08 June 2022 — Revised ※ 11 June 2022 — Accepted ※ 13 June 2022 — Issue date ※ 28 June 2022
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WEPOTK022 Horizontal Beam Response at Extraction Conditions at the Heidelberg Ion-Beam Therapy Centre 2096
SUSPMF047   use link to see paper's listing under its alternate paper code  
 
  • E.C. Cortés García, E. Feldmeier, Th. Haberer
    HIT, Heidelberg, Germany
 
  The Heidelberg Ion-Beam Therapy Centre’s synchrotron makes use of the sextupole driven RF-KO method near the third-order resonance in order to slowly extract the beam that is delivered to the patients. The horizontal beam response of a coasting beam was studied experimentally and with simulations at extraction conditions in order to deduce regions of interest for an optimal excitation signal spectrum. Two narrow frequency regions were found were the beam reacts coherently. With these information an RF signal was proposed for the resonant slow extraction.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOTK022  
About • Received ※ 17 May 2022 — Revised ※ 14 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 03 July 2022
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WEPOTK023 Simulation Study of Fast Extraction in the Absence of One Septum Magnet for J-Parc Main Ring 2100
 
  • S. Iwata, S. Igarashi, K. Ishii, H. Matsumoto, N. Matsumoto, Y. Sato, T. Shibata, T. Sugimoto, T.Y. Yasui
    KEK, Tokai, Ibaraki, Japan
 
  At J-PARC main ring (MR), the two fast extracting beamlines to the neutrino facility and to the abort dump have a symmetrical layout of 6 septum magnets each, a total of 12. Since there are many magnets, it is necessary to be careful about failure. It is important to consider how to continue beam supply even if one of the septum mag-nets is missing. From July 2021, upgrade works of the FX septum magnets commenced with an aim of increasing the beam power of MR to 1.3 MW from 500 kW. We simulated the beam extraction without one of the septum magnets under the conditions of the new geometry of septum magnets and the new aperture. We found that the beam can be extracted by increasing the current of the surrounding septum magnets and compensating for the output.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOTK023  
About • Received ※ 08 June 2022 — Revised ※ 10 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 25 June 2022
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WEPOTK024 Upgrade of Septum Magnets for Fast Extraction in J-Parc Main Ring 2103
 
  • S. Iwata, K. Ishii, H. Matsumoto, N. Matsumoto, Y. Sato, T. Shibata, T. Sugimoto, M. Uota
    KEK, Tokai, Ibaraki, Japan
 
  We aim to supply a high-power proton beam of 1.3 MW to the neutrino facility from J-PARC Main Ring (MR) by shortening the repetition cycle to 1.16 s from 2.48 s and increasing the number of particles by 30%. The six sep-tum magnets for fast extraction (FX) need to be replaced to reduce the heat that is generated as a result of shorten-ing the repetition cycle. The replacement of the septum magnets began in July 2021 and was completed at the end of May 2022. The beam commissioning starts in June 2022. We report the details of the replacement work and operation test of the new septum magnets. We found a defect in the magnetic coil of the septum (SM32) in August 2021. We decided to postpone its installation to around August 2022 and produce new magnet coils for the SM32. The beam extraction in June 2022 will be per-formed using a temporary vacuum duct instead of the SM32 magnet, and the extraction beam orbit will be maintained by increasing the magnetic field of the other five septum magnets.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOTK024  
About • Received ※ 08 June 2022 — Revised ※ 10 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 10 July 2022
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WEPOTK026 Commissioning of the ELENA Electrostatic Transfer Lines for the Antimatter Facility at CERN 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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WEPOTK028 Implementation of RF Channeling at the CERN PS for Spill Quality Improvements 2114
 
  • P.A. Arrutia Sota, H. Damerau, M.A. Fraser, M. Vadai, F.M. Velotti
    CERN, Meyrin, Switzerland
  • P. Burrows
    JAI, Oxford, United Kingdom
 
  Resonant slow extraction from synchrotrons aims at providing constant intensity spills over timescales much longer than the revolution period of the machine. However, the extracted intensity is undesirably modulated by noise on the machine’s power converters with a frequency range of between 50 Hz and a few kHz. The impact of power converter noise can be suppressed by exploiting a Radio Frequency (RF) technique known as empty bucket channelling, which increases the speed at which particles cross the tune resonance boundary. In this contribution the implementation of empty bucket channelling in the CERN Proton Synchrotron (PS) is described via simulation and measurement. The technique was tested with both a resonant RF cavity and an inductive Finemet cavity, which can produce non-sinusoidal waveforms, to significantly reduce the low frequency noise observed on the extracted spill.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOTK028  
About • Received ※ 07 June 2022 — Revised ※ 15 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 22 June 2022
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WEPOTK031 Low-Energy Negative Ion Injection Beamline for Experiments with Antiprotonic Atoms at AEgIS 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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WEPOTK043 Matching Studies Between the CERN PSB and PS Using Turn-by-Turn Beam Profile Acquisitions with a Residual Beam Gas Ionisation Monitor 2161
 
  • M.A. Fraser, M.R. Coly, A. Guerrero, A. Huschauer, S. Jensen, S. Levasseur, F. Roncarolo, A. Rossi, H.S. Sandberg, J.W. Storey
    CERN, Meyrin, Switzerland
 
  In the framework of the LHC Injectors Upgrade project, the Beam Gas Ionisation (BGI) profile monitors installed in the Proton Synchrotron (PS) were fitted with a gas injection system capable of boosting the signal rate high enough to capture single turn acquisitions immediately after injection. This contribution reports on the studies carried out during the beam commissioning of the BGI system in a turn-by-turn matching monitor mode for its eventual implementation in an optimisation framework to preserve emittance during transfer between the PS Booster and PS. The BGI commissioning included a benchmarking with data from a wire-grid secondary emission monitor inserted into the circulating beam.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOTK043  
About • Received ※ 02 June 2022 — Accepted ※ 22 June 2022 — Issue date ※ 30 June 2022  
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