Keyword: extraction
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MOYPLM1 Challenges to Higher Beam Power in J-PARC: Achieved Performance and Future Prospects operation, resonance, experiment, proton 6
 
  • S. Igarashi
    KEK, Ibaraki, Japan
 
  J-PARC is a world leading intensity frontier accelerator facility, consisting of a 400-MeV H linac, a 3-GeV Rapid Cycling Synchrotron (RCS) and a 30-GeV slow cycling Main Ring synchrotron (MR). The RCS delivered a 500 kW beam (4.2·1013 particles per pulse (ppp)) to the Material and Life science experimental Facility (MLF) in April of 2018, The design power of 1 MW will be delivered in the next few years. Construction of a second target station (2TS) of the MLF with beam power upgraded to 1.5 MW is now under discussion. The MR delivers proton beam to a long-baseline neutrino oscillation experiment, T2K, by fast extraction (FX) and to the hadron experimental facility by slow extraction (SX). For the FX, the maximum beam power is 475 kW and 2.5·1014 ppp, the world highest ppp in synchrotrons, and for the SX 51 kW and 5.5·1013 ppp with an extremely high extraction efficiency of 99.5 %. To achieve 1.3 MW beam power for the neutrino experiment, upgrades to allow operation with a higher repetition rate are planned. The talk will review recent progress of J-PARC facility by highlighting technical challenges toward higher beam power together with future prospects.  
slides icon Slides MOYPLM1 [9.193 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOYPLM1  
About • paper received ※ 15 May 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
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MOPGW024 Measurements of the GSI Transfer Beam Lines Ion Optics quadrupole, experiment, emittance, storage-ring 131
 
  • M. Sapinski, O. Geithner, S. Reimann, P. Schütt, M. Vossberg, B. Walasek-Höhne
    GSI, Darmstadt, Germany
  • C. Heßler
    CERN, Meyrin, Switzerland
 
  GSI High Energy Beam Transfer lines (HEST) link the SIS18 synchrotron with two storage rings (Experimental Storage Ring and Cryring) and six experimental caves. The recent upgrades to HEST beam instrumentation enables precise measurements of beam properties along the lines and allow for faster and more precise beams setup on targets. Preliminary results of some of the measurements performed during runs in 2018 and 2019 are presented here. The focus is on response matrix measurements and quadrupole scans performed on HADES beam line. The errors and future improvements are discussed.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW024  
About • paper received ※ 15 May 2019       paper accepted ※ 19 May 2019       issue date ※ 21 June 2019  
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MOPGW037 Dynamic Variation of Chromaticity for Beam Instability Mitigation in the 3-GeV RCS of J-PARC simulation, emittance, injection, impedance 171
 
  • P.K. Saha, H. Harada, H. Hotchi, Y. Shobuda, T. Takayanagi, F. Tamura, Y. Watanabe
    JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
 
  We have studied many other dynamic approaches from that reported in the IPAC 2018 for transverse beam instability mitigation in the presence of strong space charge in the 3-GeV RCS of J-PARC. One of such a method is the introduction of an excess of chromaticity from that of natural chromaticity by reversing the sextupole magnetic fields from the middle of the acceleration cycle. The benifits of this method are twofold. It allows to utilize sextupole for chromaticty correction at lower energy and also mitigate the beam instability at higher energy because of introducing higher chromaticity. We first carried out numerical simulations by using ORBIT code, experimentally verified and then applied for the machine operation. The detail of simulation and measurements results are presented in this paper.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW037  
About • paper received ※ 14 May 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
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MOPGW046 Proton Beam Steering for the Experimental Muon Source at CSNS proton, solenoid, target, neutron 193
 
  • Y.K. Chen, H.T. Jing
    IHEP CSNS, Guangdong Province, People’s Republic of China
  • C. Meng, Y.P. Song, J.Y. Tang, G. Zhao
    IHEP, Beijing, People’s Republic of China
 
  Experimental Muon Source (EMuS) is a muon source to be built at China Spallation Neutron Source (CSNS). The EMuS baseline design adopts a stand-alone target sitting in capture superconducting solenoids, and the muon beam is extracted in the forward direction. In the same time the spent protons are also extracted from the target station and guided to an external. Because there is an angle of 15 degrees between the axis of solenoids and the proton direction, the protons will be deviated by the solenoid field. A pair of correction magnets in front of the solenoids is used to align the incoming proton beam to the target and also guide the spent protons to the beam dump. As the target station is design to work at different field level, this increases the complexity of the proton beam transport.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW046  
About • paper received ※ 15 May 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
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MOPGW077 Impedance Reduction in the CERN SPS Through Element Layout Optimisation impedance, coupling, cavity, quadrupole 277
 
  • A. Farricker, C. Vollinger
    CERN, Geneva, Switzerland
 
  The CERN accelerator complex is currently in its long shutdown while the LHC Injector Upgrade is being carried out. The upgrade of the SPS includes but is not limited to: the relocation of the beam dumping system, upgrade of the RF system, replacement of the electrostatic septa and impedance reduction. These major upgrades present an opportunity to perform additional impedance reduction in areas not normally modified due to the large amount of work being performed across the accelerator complex. In this paper, we look at the impedance minimization in the sections near the large aperture quadrupoles of the extraction regions in the CERN SPS. By optimizing the locations of existing equipment and the introduction of a new, more impedance optimised type of bellows, significant reductions in the beam-coupling impedance can be achieved.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW077  
About • paper received ※ 08 May 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019  
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MOPGW123 Electromagnetic Study and Measurements of the iRCMS Cell focusing, optics, quadrupole, proton 403
 
  • N. Tsoupas, P.N. Joshi, F. Méot, D. Trbojevic
    BNL, Upton, Long Island, New York, USA
  • D.T. Abell
    RadiaSoft LLC, Boulder, Colorado, USA
  • V.L. Bailey, J.P. Lidestri
    Best Medical International, Springfield, USA
  • M. Sinnott
    Everson Tesla Inc., Nazareth, Pennsylvania, USA
 
  Funding: BNL Contract TSA-NF-18-80
The ion Rapid Cycle Medical Synchrotron (iRCMS) * will provide proton and C ion bunches with maximum energy 270 MeV and 450 MeV/u respectively at a frequency of 15 Hz for treating cancerous tumors. One of the six cells of the iRCMS has been designed, built and magnetic field measurements have been performed. We will present results from the static and AC electromagnetic study of the iRCMS cell and compare the measured magnetic fields with those calculated using the OPERA computer code **. In addition the beam optics of the cell will be calculated based on the experimental fields using the zgoubi computer code *** and compared with the designed beam optics.
* D. Trbojevic, iRCMS Magnet Review, BNL, Sept. 6, 2012 (unpublished)
** OPERA computer code https://operafea.com/
*** The zgoubi computer code https://www.bnl.gov/isd/documents/79375.pdf
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW123  
About • paper received ※ 15 May 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019  
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MOPRB098 An Increased Extraction Energy Booster Complex for the Jefferson Lab Electron Ion Collider booster, collider, electron, proton 797
 
  • E.A. Nissen
    JLab, Newport News, Virginia, USA
 
  Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177. The U.S. Government retains a non-exclusive, world-wide license to publish or reproduce this manuscript.
The proposed Jefferson Lab Electron Ion Collider (JLE-IC) envisions an ion complex composed of an ion linac, two booster synchrotrons and a collider ring. The evolving design of the JLEIC booster required an increase in the extraction energy of the booster from 8 to 12.1 GeV kinetic energy, necessitating two machines instead of one. The decision was also made to switch to warm magnets, thus increasing the total radius of the 8 GeV booster. The second booster is now the same size as the collider rings. In this work we present the new designs for JLEIC’s Low Energy Booster (LEB) and High Energy Booster (HEB).
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB098  
About • paper received ※ 14 May 2019       paper accepted ※ 18 May 2019       issue date ※ 21 June 2019  
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MOPTS016 Compression and Noise Reduction of Field Maps cavity, DTL, simulation, MMI 875
 
  • X. Du, L. Groening
    GSI, Darmstadt, Germany
 
  Errors from discretization and large data volume of field maps is a concern for beam dynamics simulations with respect to achievable accuracy and to the required amount of time. High-order singular value decomposition (HOSVD) has recently emerged as simple, effective, and adaptive tool to extract the essentials from multidimensional data. This paper is on the feasibility of compression and noise reduction of electromagnetic field map data with HOSVD. The method has been applied to an electric field map of a DTL cavity with 11 m in length comprising 55 rf-gaps. The original field map data of 220 MB was converted into practically noise-free data of just 20 KB. Noise was reduced by 95% as demonstrated using a cubic cavity for which the analytical field map is available.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPTS016  
About • paper received ※ 13 May 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
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MOPTS035 Recommissioning of SIS18 After FAIR Upgrades MMI, operation, controls, cavity 932
 
  • D. Ondreka, C. Dimopoulou, H.C. Hüther, H. Liebermann, J. Stadlmann, R.J. Steinhagen
    GSI, Darmstadt, Germany
 
  The synchrotron SIS18 of the GSI facility has recently resumed beam operation after a long shutdown, during which major upgrades for the operation of SIS18 in the FAIR facility were realized. This signifies a major milestone for the mission of GSI and FAIR. On one hand, the scientific program of GSI depends strongly on beam from SIS18, including the very important developments of detectors for FAIR experiments. On the other hand, large parts of the existing GSI accelerator facility, including SIS18, are now operated with the FAIR control system, demonstrating its suitability for control of a large scale accelerator facility. Commissioning of the new control system started during the shutdown with a series of dry runs, which proved very useful to establish the basic functionalities. Recommissioning of SIS18 was further facilitated by the fact that the machine model of SIS18, implemented in the modeling framework LSA, had already been tested with beam several years before the shutdown. Thus, all operation modes of SIS18, including multi-turn injection, electron cooling, as well as fast and slow extraction could be successfully commissioned during the first weeks of operation. Other commissioning activities concerned the operation of new devices installed during the shutdown. These devices, mostly installed to prepare SIS18 for the operation with FAIR design parameters, open new possibilities in the standard operation of SIS18. A challenge for the operation of SIS18 is posed by ground motion due to ground water lowering for the nearby FAIR construction site. Surveys revealed that SIS18 subsided by several centimeters during one year. Even though the machine was realigned prior to recommissioning, the dynamics of the ground motion will continue to affect operation of SIS18.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPTS035  
About • paper received ※ 15 May 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019  
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MOPTS082 Status of ESS Linac Upgrade Studies for ESSnuSB linac, ion-source, proton, neutron 1038
 
  • B. Gålnander, M. Eshraqi, C.A. Martins, R. Miyamoto
    ESS, Lund, Sweden
  • M. Collins
    Lund Technical University, Lund, Sweden
  • A. Farricker
    CERN, Geneva, Switzerland
 
  Funding: ESSnuSB has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 777419.
The European Spallation Source (ESS), currently under construction in Lund, Sweden, is the world’s most powerful neutron spallation source, with an average power of 5 MW at 2.0 GeV. In the ESS neutrino Super Beam Project (ESSnuSB) it is proposed to utilise this powerful accelerator as a proton driver for a neutrino beam that will be sent to a large underground Cherenkov detector in Garpenberg, mid-Sweden. In this paper we discuss the required modifications of the ESS linac to reach an additional 5 MW beam power for neutrino production in parallel to the spallation neutron production.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPTS082  
About • paper received ※ 17 May 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
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MOPTS096 Linac4: Reliability Run Results and Source Extraction Studies emittance, linac, simulation, plasma 1090
 
  • D. Noll, G. Bellodi, S.B. Bertolo, F.D.L. Di Lorenzo, J.-B. Lallement, J. Lettry, A.M. Lombardi, C.M. Mastrostefano, B. Mikulec, M. O’Neil, S. Schuh, R. Wegner
    CERN, Meyrin, Switzerland
 
  Linac4, a 160 MeV, 352.2 MHz linear accelerator, has been fully commissioned and will take its place as new injector to the CERN chain of accelerators during the long shutdown (LS2) in 2019-2020. In the past year, it has been continuously providing beam during a test run to assess its reliability in view of the connection to the LHC injector chain. The target reliability of more than 90% has been demonstrated during the accumulated nine months of run in 2017 and 2018. The beam quality at 160 MeV is suitable for producing all beams for the CERN physics program of today. Nevertheless, the limited peak current of 30mA might be a limitation for future high intensity programs. The bottleneck has been identified at the low energy end of the accelerator. In the meantime, beam extraction and low energy beam transport studies are ongoing at a dedicated test stand with the goal to reach beam currents from the pre-injector up to 45 mA. We will present the status of the modelling of the pre-injector and possible solutions to reach higher beam currents from the RFQ along with results from the reliability run.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPTS096  
About • paper received ※ 30 April 2019       paper accepted ※ 19 May 2019       issue date ※ 21 June 2019  
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MOPTS097 Updates on Alternative Pre-Booster Ring Design and Wiggler Magnet Considerations of SPS for the FCC e+e Injector damping, wiggler, emittance, injection 1094
 
  • O. Etisken
    Ankara University, Faculty of Sciences, Ankara, Turkey
  • F. Antoniou, Y. Papaphilippou, T. Tydecks
    CERN, Meyrin, Switzerland
  • A.K. Çiftçi
    Izmir University of Economics, Balçova/Izmir, Turkey
 
  The Future Circular e+e Collider (FCC- e+e) injector complex needs to produce and to transport a high-intensity e+e beam at a fast repetition rate for topping up the collider at its collision energy. Two different options are under consideration as pre-accelerator before the bunches are transferred to the high-energy booster: using the existing SPS and designing a completely new ring. The purpose of this paper is to explore the needs and parameters of the existing SPS, to investigate wiggler magnet options for SPS, and provide an updated study of alternative accelerator ring design with injection and extraction energies of 6 and 20 GeV, respectively. In this study, the parameters of both choices are established, including the optics design, layout update and considerations for non-linear dynamics optimization.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPTS097  
About • paper received ※ 06 May 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019  
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MOPTS107 Beam Manipulations With Barrier Buckets in the CERN PS synchrotron, proton, operation, cavity 1132
 
  • M. Vadai, A. Alomainy
    QMUL, London, United Kingdom
  • H. Damerau, S.S. Gilardoni, M. Giovannozzi, A. Huschauer
    CERN, Geneva, Switzerland
 
  A barrier bucket scheme is being considered to reduce losses during the Multi-Turn Extraction from the CERN Proton Synchrotron to the Super Proton Synchrotron for the fixed-target physics programme. For effective loss reduction, the extraction kicker has to be triggered during the gap at the time of the longitudinal barrier. Initial beam studies at injection energy and with low intensity beams allowed to fully qualify an existing wide-band cavity to generate one or multiple beam synchronous pulses per turn. Bunch-length stretching and shortening have been exercised with barriers moving in azimuth with respect to the beam. The encouraging results obtained at injection energy guided the implementation of a de-bunching manipulation at higher energy to move all bunches into a single barrier bucket. Beam measurements at a momentum of 14GeV/c, varying intensity and the width of the barrier, demonstrate that a quasi-constant longitudinal line density and an almost fully depleted gap can be achieved at highest intensities. The contribution summarises the results of the beam studies at high energy together with some observations related to the Multi-Turn Extraction.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPTS107  
About • paper received ※ 18 April 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019  
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TUPMP016 New Power Supply of Main Magnets for J-Parc Main Ring Upgrade controls, operation, quadrupole, proton 1266
 
  • T. Shimogawa, Y. Kurimoto, K. Miura, Y. Morita, D. Naito
    KEK, Ibaraki, Japan
  • R. Sagawa
    Universal Engineering, Ibaraki-ken, Japan
 
  It is plans that the proton beam power provided to experimental facilities increase with shortening repetition period in J-PARC Main Ring (MR). As the shorten repetition period, the replacement of the power converters for main magnets in J-PARC MR is necessary to cope with issues such as power fluctuation of the main grid and increase of the output voltage. We have considered and developed the power converters with a 10 MW class which have the capacitor banks with the large capacitance. In the end of 2017, the first new power converter for a bending magnets family, which is the largest power converter in this upgrade plan, was installed in J-PARC site and the power test is ongoing using a dummy and a real load. In this report, the first new power converter for a bending magnets family in J-PARC MR is reported including the test results.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPMP016  
About • paper received ※ 14 May 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
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TUPGW048 Simulation of Injection Efficiency for the High Energy Photon Source injection, booster, storage-ring, kicker 1514
 
  • Z. Duan, J. Chen, Y.Y. Guo, D. Ji, Y. Jiao, C. Meng, Y.M. Peng, Xu. Xu
    IHEP, Beijing, People’s Republic of China
 
  Funding: Work supported by Natural Science Foundation of China (No.11605212).
A ’high-energy accumulation’ scheme [1] was proposed to deliver the full charge bunches for the swap-out injec- tion of the High Energy Photon Source. In this scheme, the depleted storage ring bunches are recovered via merging with small charge bunches in the booster, before being refilled into the storage ring. In particular, the high charge bunches are transferred twice between the storage ring and the booster, and thus it is essential to maintain a near per- fect transmission efficiency in the whole process. In this paper, major error effects affecting the transmission efficiency are analyzed and their tolerances are summarized, injection simulations indicate a satisfactory transmission efficiency is achievable for the present baseline lattice.
* Z. Duan, et al., "The swap-out injection scheme for the High Energy Photon Source", Proc. IPAC’18, THPMF052
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW048  
About • paper received ※ 15 May 2019       paper accepted ※ 21 May 2019       issue date ※ 21 June 2019  
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TUPTS023 A CENTRAL REGION UPGRADE OF THE k800 SUPERCONDUCTING CYCLOTRON AT INFN-LNS cyclotron, injection, simulation, acceleration 1975
 
  • G. D’Agostino, L. Calabretta, D. Rifuggiato
    INFN/LNS, Catania, Italy
  • W.J.G.M. Kleeven
    IBA, Louvain-la-Neuve, Belgium
 
  The Superconducting Cyclotron (CS) at INFN-LNS in Catania is currently under an upgrade process. The plan is to deliver beams of ions with mass number 𝐴 ≤ 40 with power up to 10 kW. This ambitious goal can be achieved increasing the efficiency of the injection and extraction processes. An extraction efficiency close to 100% is expected by extracting the specific ion beams from the CS by stripping and no longer by electrostatic deflectors. The beams are injected axially and bent onto the median plane with a spiral inflector. Currently, the injection efficiency stays around 15%, also including the effect of a drift buncher placed in the axial injection line. In order to increase the injection efficiency, the study of an upgraded CS central region is ongoing at INFN-LNS. In this paper, the results of simulations of beam tracking through the cyclotron axial bore, the spiral inflector, the central region and further up to the extraction system are presented.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPTS023  
About • paper received ※ 29 April 2019       paper accepted ※ 21 May 2019       issue date ※ 21 June 2019  
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TUPTS025 Arc and Convertor Current Transient Studies for Multi-cusp Cesiated Surface Conversion H Source at Lansce ion-source, operation, plasma, electron 1983
 
  • D. Kleinjan
    LANL, Los Alamos, New Mexico, USA
 
  The Multi-cusp Cesiated Surface Conversion H Ion Source at the Los Alamos Neutron Science Center (LANSCE) has provided beam at ~14 mA, 120 Hz, and 10% D.F. for many years of neutron science research. Recently, random high current transients were discovered in the arc current used to ionize hydrogen in the LANSCE H ion source, and in the convertor current used to convert protons to H ions. Most have no effect, but more severe transients can cripple beam output. Hypothesized causes are related to cesiation effects, plasma potential changes, tungsten filament vaporation/sputtering, or from the pulsed power system. A dedicated study was recently done on the LANSCE H Ion source test stand to determine the cause of these transients. Current understanding indicates that the more severe transients come from a combination of cesiation effects and plasma potential changes. The status of these current transient studies on the LANSCE H ion source will be discussed.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPTS025  
About • paper received ※ 14 May 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
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TUPTS028 Extraction System of Upgraded AVF Cyclotron of RCNP proton, cyclotron, septum, injection 1993
 
  • M. Nakao, M. Fukuda, S. Hara, T. Hara, K. Hatanaka, K. Kamakura, H. Kanda, H.W. Koay, S. Morinobu, Y. Morita, K. Nagayama, T. Saito, K. Takeda, H. Tamura, Y. Yasuda, T. Yorita
    RCNP, Osaka, Japan
 
  The AVF cyclotron of RCNP have been utilized for the purposes of basic research in physics, RI production for medicine and industrial applications as well as injector of ring cyclotron. Increasing beam intensity without decreasing beam quality can make improvements in all purposes. The improvement and repair of the AVF cyclotron are being carried out currently. We designed the new LEBT, injection, acceleration and extraction systems and we report on the extraction system here. High extraction efficiency is indispensable when increasing the beam intensity since beam loss causes activation of apparatus. New extraction system consists of deflector electrodes and two gradient correctors and probes. One gradient corrector causes a horizontally focus effect on the beam and the other causes horizontally defocus effect to avoid spreading of the beam with strong defocus effect caused by the main cyclotron magnetic field. Simulation study confirmed that 10 MeV proton, 65 MeV proton and 140 MeV alpha particles with 2 mm × 3 mrad could pass through the newly designed extraction system and the existing beam transport line. Beam simulation has been performed by utilizing SNOP* and OPAL** codes.
* SNOP V.L. Smirnov, S.B. Vorozhtsov, Proc. of RUPAC2012 TUPPB008 325 (2012)
** The OPAL (Object Oriented Parallel Accelerator Library) Framework, Andreas Adelmann et al., PSI-PR-08-02, (2008-2018)
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPTS028  
About • paper received ※ 01 May 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
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TUPTS029 The New Eddy Current type Septum Magnets for Upgrading of Fast Extraction in Main Ring of J-PARC operation, septum, experiment, feedback 1997
 
  • T. Shibata, K. Ishii, H. Matsumoto, T. Sugimoto
    KEK, Ibaraki, Japan
  • K. Fan
    HUST, Wuhan, People’s Republic of China
  • K. Hamano
    Nichicon (Kusatsu) Corporation, Shiga, Japan
 
  The J-PARC Main Ring (MR) is working on imporved beam to 750 kW by shorting the repetition period from 2.48 s to 1.3 s which we call 1Hz operation. The septum magnets for fast extraction in MR will be improved to the new septum magnets which can operate 1Hz. The new magnets will be installed to MR in 2021. In this poster we will report about the new low field septum magnet for the fast extraction. The present septum magnets are conventional type. Therefore, we have problem in durability of thin septum coil by its magnetic vibration, and large leakage field at the exit of the circulating beam duct. The new septum magnets are eddy current type. The eddy current type does not have septum coil, but has a thin septum plate. We can expect that there is no problem in durability of septum coil, and leakage field can be reduced. The output of the present power supply are pattern current which of flat top is 10 ms width, the new one is short pulse which of one is 10 us. The short pulse consists of fundamental and 3rd harmonic sin-wave pulse. We can expect that the flatness and reproducibility of flat top current can be improved. We confirmed that 1Hz operation and high accuracy of its output current and magnetic field with the new septum magnet system. We had some problem in unexpected instability of output current. In this report we also summarize the measure against the instabillity.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPTS029  
About • paper received ※ 26 April 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
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TUPTS030 The New High Field Septum Magnets for Upgrading of Fast Extraction in Main Ring of J-PARC operation, septum, flattop, power-supply 2001
 
  • T. Shibata, K. Ishii, H. Matsumoto, T. Sugimoto
    KEK, Ibaraki, Japan
  • K. Fan
    HUST, Wuhan, People’s Republic of China
 
  The J-PARC Main Ring (MR) is working on imporved beam to 750 kW by shorting the repetition period from 2.48 s to 1.3 s which we call 1Hz operation. There are fout high field septum magnet along the fast extraction line in the MR, and these will be improved to the new magnets which can operate 1Hz frequency. The new high field septa will be installed in 2021. In this poster we will report about the performance of these new septum magnets. These high field septum magnets are called Septum 30(SM30), 31(SM31), 32(SM32), 33(SM33). We will replace SM30, SM31, and SM32. One reasons of cethe replacement is installation of a large-size quadrupole magnet to upsteam postion of the septa. We need to change the longitudinal length of the septa. Second is large aperture of the beam duct for reduction of beam loss by the collision of the halo of the proton beam to the duct. The new high field SM30, SM31 and SM32 have large aperture. and the material of the beam ducts for extraction line are ceramics for reduction of amount of heat generation by eddy current on the surface of the duct. The maetial of the circulating duct are titanium for reduction of radioactivation. On the other hand, the power supply will not be replaced, then the current power supplies will be used for these new septa. The new SM30, SM31, and SM32 were produced in 2015. The first test operation of SM31 were conduced with 2.48 s repein 2015, and we have meaured the magnetic field without problem. In 2018, we conduced the first 1Hz operation with SM30. The minimum repetition period of the operation was 1.16 s without any problem. We measuered magnetic fields in the gap of the pole and in the circulating beam duct. In this report we will report the detail of the results of the operation and field measurement.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPTS030  
About • paper received ※ 26 April 2019       paper accepted ※ 21 May 2019       issue date ※ 21 June 2019  
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TUPTS060 Beam Dynamics Simulations in the Dubna SC230 Superconducting Cyclotron for Proton Therapy cyclotron, simulation, acceleration, proton 2061
 
  • G.A. Karamysheva, S. Gurskiy, O. Karamyshev, D.V. Popov, G. Shirkov, S.G. Shirkov, V.L. Smirnov, S.B. Vorozhtsov
    JINR, Dubna, Moscow Region, Russia
  • V. Malinin
    JINR/DLNP, Dubna, Moscow region, Russia
 
  We present results of the beam dynamics simulation for the compact isochronous superconducting cyclotron SC230. We have performed beam tracking starting from the ion source. The extraction system scheme and results of beam extraction simulations are presented. The codes and methods used for beam tracking are briefly described.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPTS060  
About • paper received ※ 15 May 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019  
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WEPMP007 Current Status of Slow Extraction from J-PARC Main Ring operation, proton, experiment, radiation 2311
 
  • R. Muto, Y. Arakaki, T. Kimura, S. Murasugi, M. Okada, K. Okamura, T. Shimogawa, Y. Shirakabe, M. Tomizawa, T. Toyama, E. Yanaoka
    KEK, Ibaraki, Japan
  • A. Matsumura
    Nihon Advanced Technology Co., Ltd, Ibaraki, Nakagun, Tokaimura, Japan
 
  A 30 GeV proton beam accelerated in the J-PARC Main Ring (MR) is slowly extracted by the third integer resonant extraction and delivered to the hadron experimental hall. The slow extraction (SX) from the MR has unique characteristics that can be used to obtain a low beam loss rate. A dynamic bump scheme under achromatic condition drastically reduces beam hit rate on the septa devices. We have attained 50 kW SX operation at 5.2s cycle in current physics run. Slow extraction efficiency has been achieved to be very high, 99.5%. A beam instability during debunching with beam loss can be suppressed by a unique RF phase offset technique at MR injection. A spill duty factor indicating a uniformity for time structure of the extracted beam is typically 50%, which can be obtained by a feedback system using fast response quadrupoles, applying transverse RF field and so on. Future plans to improve present SX performances will be introduced.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPMP007  
About • paper received ※ 01 May 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019  
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WEPMP008 A Consideration on the Transfer Function Between RQ Field and Slow Extraction Spill in the Main Ring of J-Parc feedback, experiment, operation, controls 2315
 
  • K. Okamura, Y. Arakaki, S. Murasugi, R. Muto, Y. Shirakabe, M. Tomizawa, E. Yanaoka
    KEK, Ibaraki, Japan
  • T. Kimura
    J-PARC, KEK & JAEA, Ibaraki-ken, Japan
 
  A 30 GeV proton beam accelerated in the J-PARC Main Ring (MR) is slowly extracted by the third integer reso-nant extraction and delivered to the hadron experimental facility. Increasing the duty of beam spill is one of the important issues in the slow extraction system. In the MR, the spill feedback system utilizing a digital signal processor (DSP) combined with EQ and RQ magnet is used to smooth the spill, where EQ defines a rough out-line of the slow extraction shape and RQ is used for the ripple cancelling. In this study, frequency domain charac-teristics between the current of RQ magnet and the beam spill was investigated by driving the RQ magnet with sinusoidal current, so that the transfer function from the current of RQ magnet to the spill signal is delivered.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPMP008  
About • paper received ※ 15 May 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019  
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WEPMP010 8 Gev Slow Extraction Beam Test for Muon to Electron Conversion Search Experiment at J-PARC kicker, timing, injection, electron 2322
 
  • M. Tomizawa, Y. Arakaki, Y. Fukao, Y. Hashimoto, Y. Igarashi, T. Kimura, S. Mihara, M. Moritsu, S. Murasugi, R. Muto, H. Nishiguchi, K. Okamura, Y. Shirakabe, K. Ueno, E. Yanaoka
    KEK, Ibaraki, Japan
  • Y. Fujii
    Monash University, Faculty of Science, Clayton, Victoria, Australia
  • F. Tamura
    JAEA/J-PARC, Tokai-mura, Japan
 
  A muon to electron conversion search experiment (COMET) planned at J-PARC needs 8 GeV bunched proton beams with a continuous 1 MHz pulse structure. In this experiment, an intensity ratio of the residual to the main pulsed beam, which is expressed as extinction, should be less than the level of 10-10. In RUN78 (Jan. to Feb., 2018), we have succeeded in slow extraction of 8 GeV protons with 7.3×1012 ppp, satisfies the COMET phase-I requirement, and the extinction derived from a timing measurement of secondary particles from the target shows a promising result. A mechanism to explain the measured extinction will be also described in this paper.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPMP010  
About • paper received ※ 01 May 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
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WEPMP014 Slow Extraction Study by Using Sextupole sextupole, synchrotron, resonance, proton 2332
 
  • L. Huang, S. Wang
    IHEP, Beijing, People’s Republic of China
 
  The spill continuously extracted from synchrotron by using resonance sextupoles plays a key role in multidisciplinary application. The intensity of virtual sextupole and the spiral step for the typical synchrotron are obtained theoretically. A customized synchrotron of extraction components placed in dispersion section is designed and the tracking code of slow extraction is developed, thus the theoretical spiral step is comparative studied. To study the beam loss, three layouts of extraction are also designed based on the synchrotron. The result shows that the beam losses at extraction point are different for three cases and it is advantage to beam loss for extraction components placed in dispersion-free straight section.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPMP014  
About • paper received ※ 15 May 2019       paper accepted ※ 21 May 2019       issue date ※ 21 June 2019  
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WEPMP022 Design and Construction of the CERN SPS Extraction Protection Elements for LIU vacuum, simulation, quadrupole, brightness 2359
 
  • B. Balhan, C. Baud, J.C.C.M. Borburgh, M.A. Fraser, M. Hourican, L.O. Jorat, F.-X. Nuiry, S. Pianese
    CERN, Geneva, Switzerland
 
  At CERN, the SPS synchrotron is equipped with two fast extraction channels towards the LHC. As a part of the LHC injector upgrade project (LIU), the protection devices upstream of the septa in both extraction channels will be upgraded. Various failure scenarios have been studied and presented in the past, but the definitive approach for the equipment protection upgrade for each channel has now been determined. This paper describes the consequences of the most significant failure scenarios and the impact of the heat deposition in the diluter. The resulting material stresses are evaluated. The detailed layout for the extraction protection equipment for each extraction channel is outlined. The final layout consists of a extended diluter in Long Straight Section (LSS) 6 (TPSG6) and the installation of an additional movable absorber (TPSC4) upstream of the quadrupole in front of the existing protection equipment in LSS 4. The detailed mechanical design of the TPSC4 and the construction status of both TPSC4 and TPSG6 are discussed.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPMP022  
About • paper received ※ 10 May 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019  
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WEPMP024 Alternative Material Choices to Reduce Activation of Extraction Equipment shielding, radiation, vacuum, proton 2363
 
  • D. Björkman, B. Balhan, J.C.C.M. Borburgh, L.S. Esposito, M.A. Fraser, B. Goddard, L.S. Stoel, H. Vincke
    CERN, Geneva, Switzerland
 
  At CERN, the Super Proton Synchrotron (SPS) is equipped with a resonant slow extraction system in Long Straight Section 2 (LSS2) towards the fixed target (FT) beam lines in the North Area. The extraction region provides the physics experiments with a quasi-DC flux of high-energy protons over a few seconds, which corresponds to tens of thousands of turns. The resonant slow extraction process provokes beam losses and is therefore the origin of radiation damage and the production of induced radioactivity in this region of the machine. This induced radioactivity imposed high constraints on the equipment design to be reliable to minimise the radiation exposure to personnel during machine maintenance. A detailed FLUKA model was developed in order to better understand the beam loss patterns, activation of the machine and to identify equipment components that could be optimised to reduce the residual dose related hazards. Simulations identified multiple alternative materials for extraction equipment components as well as shielding locations, which implementation could reduce residual activation hazards.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPMP024  
About • paper received ※ 26 April 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
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WEPMP026 Emittance Dilution from the CERN Proton Synchrotron Booster’s Extraction Kickers kicker, emittance, operation, proton 2371
 
  • M.A. Fraser, S.C.P. Albright, F. Antoniou, G.P. Di Giovanni, Y. Dutheil, V. Forte, A. Huschauer, F. Roncarolo
    CERN, Meyrin, Switzerland
 
  Understanding the different sources of emittance dilution along the LHC injector chain is an important part of providing the high brightness proton beams demanded by the LHC Injectors Upgrade (LIU) project. In this context, the first beam-based measurements of the magnetic waveforms of the Proton Synchrotron Booster’s (PSB) extraction kickers were carried out and used to quantify the transverse emittance blow-up during extraction and transfer to the Proton Synchrotron (PS). In this contribution, the waveform measurement technique will be briefly outlined before the results and their implications for the LIU project and beam performance reach are discussed.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPMP026  
About • paper received ※ 14 May 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019  
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WEPMP027 Update on Beam Transfer Line Design for the SPS Beam Dump Facility target, proton, experiment, quadrupole 2375
 
  • Y. Dutheil, J. Bauche, L.A. Dougherty, M.A. Fraser, B. Goddard, C. Heßler, V. Kain, J. Kurdej, J.A. Uythoven, F.M. Velotti
    CERN, Geneva, Switzerland
 
  The SPS Beam Dump Facility (BDF) being studied as part of the Physics Beyond Colliders (PBC) CERN project has recently reached an important milestone with the completion of the comprehensive feasibility study. The BDF is a proposed fixed target facility to be installed in the SPS North Area, to accommodate experiments such as SHiP (Search for Hidden Particles), which is most notably aiming at studying hidden sector particles. This experiment requires a high intensity slowly extracted 400 GeV proton beam with 4·1013 protons per 1 s spill to achieve 4·1019 protons on target per year. The extraction and transport scheme will make use of the first 600 m of the existing North Area extraction line. This contribution presents the status of the design work of the new transfer line and discusses the challenges identified. Aperture studies and failure scenarios are treated and the results discussed. In particular, interlock systems aiming at protecting critical components against the uncontrolled loss of the high energy proton beam are considered. We also present the latest results and implications of the design of a new laminated Lambertson splitter magnet to provide fast switching between the current North Area experiments and the BDF.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPMP027  
About • paper received ※ 13 May 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019  
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WEPMP028 Crystal for Slow Extraction Loss-Reduction of the SPS Electrostatic Septum proton, experiment, ECR, alignment 2379
 
  • L.S. Esposito, P. Bestman, M.E.J. Butcher, M. Calviani, M. Di Castro, M. Donzé, M.A. Fraser, M. Garattini, Y. Gavrikov, S.S. Gilardoni, B. Goddard, V. Kain, J. Lendaro, A. Masi, M. Pari, J. Prieto, R. Rossi, W. Scandale, R. Seidenbinder, P. Serrano Galvez, L.S. Stoel, F.M. Velotti, V. Zhovkovska
    CERN, Geneva, Switzerland
  • F.M. Addesa, F. Iacoangeli
    INFN-Roma, Roma, Italy
  • A.G. Afonin, Y.A. Chesnokov, A.A. Durum, V.A. Maisheev, Yu.E. Sandomirskiy, A.A. Yanovich
    IHEP, Moscow Region, Russia
  • J.E. Borg, M. Garattini, G. Hall, T. James, M. Pesaresi
    Imperial College of Science and Technology, Department of Physics, London, United Kingdom
  • A.S. Denisov, Y. Gavrikov, Yu.M. Ivanov, M.A. Koznov, L.G. Malyarenko, V. Skorobogatov
    PNPI, Gatchina, Leningrad District, Russia
  • F. Galluccio
    INFN-Napoli, Napoli, Italy
  • A.D. Kovalenko, A.M. Taratin
    JINR, Dubna, Moscow Region, Russia
  • F. Murtas
    INFN/LNF, Frascati, Italy
  • A. Natochii
    LAL, Orsay, France
 
  The use of a bent crystal was investigated in order to reduce the losses at the CERN Super Proton Synchrotron (SPS) electrostatic septa (ZS) during the slow extraction of 400 GeV protons toward the North Area. The crystal, installed a few meters upstream the ZS, bends protons that would otherwise impinge on the ZS wires. Since particle deflection with good efficiency is achieved only when the crystal lattice is aligned within ~10 urad to the trajectory of the particles (at p = 400 GeV/c), a compact goniometer was built to allow the correct angular alignment of the crystal with respect to the incoming beam with a precision of few urad. In this paper, we report on the crystal features measured during a dedicated beam test by the UA9 experimental installation in the CERN H8 beam line. Details of the goniometer and its installation are also reported. The first results achieved during dedicated Machine Development (MD) sessions are finally presented.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPMP028  
About • paper received ※ 14 May 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019  
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WEPMP030 LHC Injection Losses and Trajectories During Run 1 and 2 and Outlook to Injection of HL-LHC Beams injection, kicker, operation, emittance 2387
 
  • W. Bartmann, C. Bracco, B. Goddard, F.M. Velotti, J. Wenninger
    CERN, Geneva, Switzerland
 
  The LHC turn-around time is impacted by the control of injection losses and trajectories. While shot-to-shot trajectory variations dominated the injection efficiency during LHC Run 1, several improvements of hardware and operational settings allowed for a high rate of successful injections during Run 2. Injection losses and trajectories are analysed and presented for the high intensity proton runs, as well as for different beam types used from the injectors. Based on this analysis, an outlook is shown for the HL-LHC era, where double the bunch intensity will have to be injected.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPMP030  
About • paper received ※ 14 May 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
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WEPMP031 SPS Slow Extraction Losses and Activation: Update on Recent Improvements operation, octupole, proton, alignment 2391
 
  • M.A. Fraser, B. Balhan, H. Bartosik, J. Bernhard, C. Bertone, D. Björkman, J.C.C.M. Borburgh, M. Brugger, N. Charitonidis, N. Conan, K. Cornelis, Y. Dutheil, L.S. Esposito, R. Garcia Alia, L. Gatignon, C.M. Genton, B. Goddard, C. Heßler, Y. Kadi, V. Kain, A. Mereghetti, M. Pari, M. Patecki, J. Prieto, S. Redaelli, F. Roncarolo, R. Rossi, W. Scandale, N. Solieri, J. Spanggaard, O. Stein, L.S. Stoel, F.M. Velotti, H. Vincke
    CERN, Meyrin, Switzerland
  • D. Barna, K. Brunner
    Wigner Research Centre for Physics, Institute for Particle and Nuclear Physics, Budapest, Hungary
 
  Annual high intensity requests of over 1019 protons on target (POT) from the CERN Super Proton Synchrotron (SPS) Fixed Target (FT) physics program continue, with the prospect of requests for even higher, unprecedented levels in the coming decade. A concerted and multifaceted R&D effort has been launched to understand and reduce the slow extraction induced radioactivation of the SPS and to anticipate future experimental proposals, such as SHiP* at the SPS Beam Dump Facility (BDF)**, which will request an additional 4·1019 POT per year. In this contribution, we report on operational improvements and recent advances that have been made to significantly reduce the slow extraction losses, by up to a factor of 3, with the deployment of new extraction concepts, including passive and active (thin, bent crystal) diffusers and extraction on the third-integer resonance with octupoles. In light of the successful tests of the prototype extraction loss reduction schemes, an outlook and implications for future SPS FT operation will be presented.
* A. Golutvin et al., Rep. CERN-SPSC-2015-016 (SPSC-P-350), CERN, Geneva, Switzerland, Apr. 2015.
** M. Lamont et al., Rep. CERN-PBC-REPORT-2018-001, CERN, Geneva, Switzerland, 11 Dec 2018.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPMP031  
About • paper received ※ 14 May 2019       paper accepted ※ 21 May 2019       issue date ※ 21 June 2019  
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WEPMP032 Tracking Simulations of Shadowing Electrostatic Septum Wires by Means of Bent Crystals simulation, septum, optics, experiment 2395
 
  • F.M. Velotti, M.A. Fraser, B. Goddard, V. Kain, L.S. Stoel
    CERN, Meyrin, Switzerland
 
  The Super Proton Synchrotron (SPS) slow extraction is a third integer resonant extraction and hence suffers from high losses at the electrostatic septum (ZS). This is one of the main limiting factors for the maximum number of Protons On Target (POT) deliverable from the SPS to the North Area (NA). A concept to significantly reduce the extraction losses via shadowing of the electrostatic septum wires using an upstream bent crystal has been proposed in *, predicting a loss reduction of up to 50% for the prototype system installed in 2018. Following the successful experimental demonstration of the concept with beam **, detailed tracking simulations have been performed to fully understand the results obtained. Further insights, such as the effective ZS width and its alignment, could be deduced by exploiting the response of the extraction loss as a function of the two degrees of freedom of the crystal (position and angle). In this paper, the beam dynamics simulations are discussed together with the implementation of the bent crystal into the simulation framework. A comparison with measurements is presented before proposals for new configurations and parameters are discussed.
* F.M. Velotti, et al., "Reduction of Resonant Slow Extraction Losses…", IPAC’18.
** F.M. Velotti, M.A. Fraser, et al., "Experimental SPS Slow Extraction Loss Reduction…", this conf.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPMP032  
About • paper received ※ 15 May 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019  
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WEPMP033 Slow Extraction Loss Reduction With Octupoles at the CERN SPS septum, octupole, multipole, proton 2399
 
  • L.S. Stoel, H. Bartosik, M. Benedikt, M.A. Fraser, B. Goddard, V. Kain, F.M. Velotti
    CERN, Meyrin, Switzerland
 
  The powering of octupoles during third-integer resonant slow extraction has been studied and recently tested with beam at the CERN Super Proton Synchrotron (SPS) in order to increase the extraction efficiency and reduce the induced radioactivity of the extraction straight. The octupoles distort the particle trajectories in phase space in such a way that the extracted separatrix is folded, which decreases the particle density impinging the wires of the extraction septum at the expense of increasing the extracted beam emittance. During experimental SPS machine studies a reduction of over 40% in the specific (per extracted proton) beam loss measured at the extraction septum was demonstrated. In this paper, the prerequisite studies needed to safely but efficiently deploy the new extraction scheme in a limited time-frame are described, the experimental results are presented and an outlook is given towards the next steps to bring slow extraction with octupoles into routine operation.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPMP033  
About • paper received ※ 14 May 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
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WEPMP034 Characterisation of SPS Slow Extraction Spill Quality Degradation quadrupole, dipole, flattop, target 2403
 
  • F.M. Velotti, H. Bartosik, M.C.L. Buzio, K. Cornelis, V. Di Capua, M.A. Fraser, B. Goddard, V. Kain
    CERN, Meyrin, Switzerland
 
  The main physics users of the Super Proton Synchrotron (SPS) are the experiments installed in the North Area (NA). They are supplied with slowly extracted protons or heavy ions, exploiting a third integer slow extraction to provide a 4.8 s spill. High duty cycle and constant particle flux are the main requirements. Frequent super cycle changes induce variation of the spill macro structure which directly deteriorate the final spill quality. In this paper, the source of such an effect are investigated. Results of both beam based measurements and direct magnetic measurements on the SPS reference magnets are presented. Finally, a possible strategy to counteract this effect is discussed, in order to try to remove the super cycle changes variation as cause for spill quality deterioration.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPMP034  
About • paper received ※ 15 May 2019       paper accepted ※ 21 May 2019       issue date ※ 21 June 2019  
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WEPMP035 Model and Measurements of CERN-SPS Slow Extraction Spill Re-Shaping - the Burst Mode Slow Extraction experiment, operation, sextupole, simulation 2406
 
  • M. Pari, M.A. Fraser, B. Goddard, V. Kain, L.S. Stoel, F.M. Velotti
    CERN, Geneva, Switzerland
 
  The ENUBET ("Enhanced NeUtrino BEams from kaon Tagging") Project aims at reaching a new level of precision of the short-baseline neutrino cross section measurement by using an instrumented decay tunnel. The North Area (NA) experimental facility of the Super Proton Synchrotron (SPS) offers the required infrastructure for the experiment. A new slow extraction type, consisting of bursts of many consecutive millisecond spills within one macro spill, has been modeled and tested for the ENUBET Project. The burst-mode slow extraction has been tested for the first time at CERN-SPS, and MADX simulations of the process have been developed. In this paper the experimental results obtained during the test campaign are presented along with the results of the quality of the produced spill and comparing it with predictions from simulations.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPMP035  
About • paper received ※ 12 May 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019  
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WEPMP044 Mu2e Electrostatic Septa Volumetric Exchange of Fc-40 Dielectric in High Radiation Environments radiation, GUI, septum, cathode 2434
 
  • M.L. Alvarez, A. Deshpande, K.R. Hunden, V.P. Nagaslaev, E. Pirtle
    Fermilab, Batavia, Illinois, USA
 
  Funding: * Operated by FRA, LLC under Contract No. DEAC02-07CH11359 and Grant Award No. LAB 18-1802 with the United States Department of Energy.
Two electrostatic septa (ESS) are being designed for the slow extraction of 8 GeV proton beam for the Mu2e experiment at Fermilab. Special attention is given to the high voltage feedthrough (HVF), which energizes the cathode creating the bending field. The FC-40 dielectric fluid, surrounding the HV cable breaks down from radiation exposure, which reduces its insulating capabilities. The new HVF design focuses on effective replacement of the exposed fluid and eliminating the stagnant areas of low exchange rate. A preliminary test using a fully transparent prototype HVF and water was conducted to understand the volumetric exchange rate of the high radiation region. Here we discuss the results of these tests and further studies using the FC-40.
** malvare4@fnal.gov
*** vnagasl@fnal.gov
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPMP044  
About • paper received ※ 14 May 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
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WEPMP045 Higher Multipoles in 3rd Integer Resonance Extraction octupole, sextupole, multipole, simulation 2437
 
  • V.P. Nagaslaev
    Fermilab, Batavia, Illinois, USA
  • K.A. Brown
    BNL, Upton, Long Island, New York, USA
  • M. Tomizawa
    KEK, Ibaraki, Japan
 
  The efficiency of slow extraction is becoming a limiting factor, as the demand for delivered beam power is constantly growing. New methods for improving extraction efficiency include folding the extraction separatrix using the higher multipoles. In this report we discuss a simple and effective approach to determine an optimal placement of those multipoles in the storage ring. This allows reduction of the beam losses and therefore, the level of prompt and residual radioactivity in the accelerator components and surrounding buildings by as much as 40% or more. We also explore here manipulating the higher order effects produced in the pure sextupole configurations for the same purpose and demonstrate that similar results can be achieved by only rearranging the sextupole magnets in the lattice.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPMP045  
About • paper received ※ 10 May 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
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WEPGW019 Performance of the CVD Diamond Based Beam Quality Monitoring System in the HADES Experiment at GSI* monitoring, detector, experiment, target 2507
 
  • A. Rost, T. Galatyuk
    TU Darmstadt, Darmstadt, Germany
  • J. Adamczewski-Musch, S. Linev, J. Pietraszko, M. Sapinski, M. Traxler
    GSI, Darmstadt, Germany
 
  Funding: Work supported by the DFG through GRK 2128 and VH-NG-823.
The beam quality monitoring of extracted beams from SIS18 at GSI, transported to the HADES experiment is of great importance to ensure a high efficient data recording. The main detector system used for this purpose is the Start-Veto system which consists of two diamond based sensors made of pcCVD and scCVD diamond materials. Both sensors are equipped with a double-sided strip segmented metallization (300 µm width) which allows a position determination of the beam. Those sensors are able to deliver a time precision <100 ps and can handle rate capabilities up to 107 particles/s/channel. Beside the diamond sensors a plastic scintillation based beam halo detector is used. The read-out of the detectors is based on the TRB3 system*. A 264 channel TDC (Time to Digital Converter) is implemented in FPGA technology with 10 ps precision. The TRB3 system serves as a fast and flexible Data Acquisition System (DAQ) with integrated scaler capability. The analysis and online visualization is performed using the Data Acquisition Backbone Core (DABC)** framework. In this contribution the performance of the system, which was used in order to evaluate an Ar and Ag ion beam delivered by the SIS 18 accelerator, will be discussed.
* A. Neiser et al., JINST 8 (2013) C12043
** J. Adamczewski-Musch et al., J.Phys. Conf. Ser. 664 (2015) no.8, 082027
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPGW019  
About • paper received ※ 15 May 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
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WEPGW030 Beam Profile Monitor for Slow Extracted Beam Using Multi-Layered Graphene at J-PARC target, electron, proton, real-time 2532
 
  • Y. Hashimoto, Y. Hori, R. Muto, M. Tomizawa, T. Toyama, M. Uota
    KEK, Tokai, Ibaraki, Japan
  • M. Endo, H. Sakai
    Mitsubishi Electric System & Service Co., Ltd, Tsukuba, Japan
  • M. Murakami, K. Murashima, M. Tachibana, A. Tatami
    KANEKA, Osaka, Japan
 
  Extracted-beam profiles in slow extraction at J-PARC has been measured by using secondary electrons emitted from a target array made by multi-layered graphen, in real time during spill time of around 2 seconds. The target array consists of 20 ribbons with width of 1 mm, pitch of 2 mm, and thickness of 1.1 micron. Secondary-electron current at each channel is measured by a current amplifier having sensitivity more than 1 pA. These configuration produces useful information for beam dynamics in slow extraction. We have set this monitor at the entrance of a septum magnet, then we can also measure the last few-turns beam with the extracted beam simultaneously. We will discuss about features of this instrument and recent beam study with 51 kW extracted-beams.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPGW030  
About • paper received ※ 15 May 2019       paper accepted ※ 21 May 2019       issue date ※ 21 June 2019  
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WEPGW039 Multi-Ribbon Profile Monitor for High Power Proton Beam at J-PARC MR Abort Line target, proton, emittance, electron 2561
 
  • K. Sato
    The University of Tokyo, Graduate School of Science, Tokyo, Japan
  • E. Hamada, Y. Hashimoto, S. Igarashi, T. Koseki, Y. Sato
    KEK, Tsukuba, Japan
 
  Japan Proton Accelerator Research Complex (J-PARC) Main Ring (MR), the world-class high intensity proton synchrotron, provides proton beam to two experimental facilities with two extraction modes: Fast extraction (FX) and Slow extraction (SX). The number of protons per pulse (ppp) in MR recorded the world highest value of 2.6×1014 in the FX mode. Now we are planning to increase the ppp further up to 3.3×1014 in near future. The beam profile is one of the most important parameters to discuss the high intensity beam dynamics in MR. Monitors using multi-wires / ribbons are effective to measure the beam profile with good accuracy and wide dynamic range. However, they cause significant beam losses by interactions with high-intensity circulating beam in synchrotrons. Recently, we installed new multi-ribbon profile monitor (MRPM) in an abort line in MR. The abort line is one of the extracted beam lines of the FX system. It has a quadrupole doublet which is called Abort Q and transports extracted beam to a beam dump. The FX system can extract the circulating beam in MR with an arbitrary energy. Performing the single-pass measurement with MRPM and changing the transfer matrix by sweeping field strength of Abort Q, the emittance of the extracted beam can be measured. In this paper, we present the design, manufacturing, and results of the first beam test of newly installed MRPM system.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPGW039  
About • paper received ※ 01 May 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
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WEPGW092 Nanosecond-Latency Sub-Micron Resolution Stripline Beam Position Monitor Signal Processor for CLIC feedback, detector, kicker, luminosity 2705
 
  • R.L. Ramjiawan, D.R. Bett, P. Burrows, G.B. Christian, C. Perry
    JAI, Oxford, United Kingdom
 
  A high-resolution, low-latency stripline beam position monitor (BPM) signal processor has been developed for use in an intra-train feedback system for the Compact Linear Collider (CLIC). The processor was designed to have extremely low latency of order nanoseconds and a target position resolution of order 1 micron. The processor consists of a pair of diodes to form the difference and sum of a pair of stripline BPM inputs with microstrip filters to reduce out-of-band noise. The assembled prototype was optimized for use with the electron beam in the extraction line of the Accelerator Test Facility at the High Energy Accelerator Research Organization (KEK) in Japan but the underlying design is readily scaleable to a higher frequency response relevant for CLIC. A latency of 3 ns was measured in a testbench setup. We report the results of performance tests with beam in which the position resolution was measured to be c. 325 nm.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPGW092  
About • paper received ※ 15 May 2019       paper accepted ※ 21 May 2019       issue date ※ 21 June 2019  
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WEPTS033 A High-performance Code for Beam Dynamics Simulation of Synchrotrons simulation, synchrotron, sextupole, proton 3170
 
  • H.J. Yao, X. Guan, G.R. Li, P.F. Ma, X.W. Wang, Q. Zhang, S.X. Zheng
    TUB, Beijing, People’s Republic of China
 
  This paper introduces a high-performance code Li-track for beam dynamics simulation of synchrotrons. It is a parallel multi-particle tracking program written entirely in C++ and therefore has a high computational speed. The overall design of Li-track is based on object-oriented mode, and the implemented element model can be easily reused to build different synchrotron lattice. The symplectic integral algorithm is used to ensure there are no physical errors in a long-term simulation. This code has been used for the slow extraction simulation of XiPAF synchrotron and the results will be given in this paper.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPTS033  
About • paper received ※ 30 April 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
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THXPLM1 LHC Injectors Upgrade Project: Towards New Territory Beam Parameters target, proton, operation, injection 3385
 
  • M. Meddahi, R. Alemany-Fernández, H. Bartosik, G. Bellodi, J. Coupard, H. Damerau, G.P. Di Giovanni, F. B. Dos Santos Pedrosa, A. Funken, B. Goddard, K. Hanke, A. Huschauer, V. Kain, A.M. Lombardi, B. Mikulec, S. Prodon, G. Rumolo, R. Scrivens, E.N. Shaposhnikova
    CERN, Meyrin, Switzerland
 
  The LHC injectors Upgrade (LIU) project aims at increasing the intensity and brightness in the LHC injectors in order to match the challenging requirements of the High-Luminosity LHC (HL-LHC) project, while ensuring high availability and reliable operation of the injectors complex up to the end of the HL-LHC era (ca. 2035). This requires extensive hardware modifications and new beam dynamics solutions in the entire LHC proton and ion injection chains: the new Linac4, the Proton Synchrotron Booster, the Proton Synchrotron the Super Proton Synchrotron together with the ion PS injectors (the Linac3 and the Low Energy Ion Ring). All hardware modifications will be implemented during the 2019-2020 CERN accelerators shutdown. This talk would analyze the various project phases, share the lessons learned, and conclude on the expected beam parameter reach, together with the related risks.  
slides icon Slides THXPLM1 [20.029 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THXPLM1  
About • paper received ※ 14 May 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
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THXXPLM1 NUCLOTRON Development for NICA Acceleration Complex acceleration, proton, injection, target 3396
 
  • E. Syresin, N.N. Agapov, A.V. Alfeev, V. Andreev, A.A. Baldin, A.M. Bazanov, O.I. Brovko, V.V. Bugaev, A.V. Butenko, D.E. Donets, E.D. Donets, E.E. Donets, A.V. Eliseev, V.V. Fimushkin, B.V. Golovenskiy, E.V. Gorbachev, A. Govorov, E.V. Ivanov, V. Karpinsky, V. Kekelidze, H.G. Khodzhibagiyan, A. Kirichenko, V.V. Kobets, S.A. Kostromin, A.D. Kovalenko, O.S. Kozlov, K.A. Levterov, D.A. Lyuosev, A.A. Martynov, I.N. Meshkov, V.A. Mikhailov, V.A. Monchinsky, A. Nesterov, A.L. Osipenkov, D.O. Ponkin, S. Romanov, P.A. Rukojatkin, K.V. Shevchenko, I.V. Shirikov, A.A. Shurygin, A.O. Sidorin, V. Slepnev, A.V. Smirnov, G.V. Trubnikov, A. Tuzikov, B. Vasilishin
    JINR, Dubna, Moscow Region, Russia
  • A. Belov
    RAS/INR, Moscow, Russia
  • A.V. Philippov, V. Volkov
    JINR/VBLHEP, Dubna, Moscow region, Russia
 
  The Nuclotron is the basic facility of JINR used to generate beams of protons, polarized deuterons and protons, and multi charged ions in the energy range of up to 5.6 GeV/n. Polarized deuteron and proton beams were obtained at the intensity of 2×109 ppp and 108 ppp, respectively. The injection with RF adiabatic capture was used in two last Nuclotron runs where C6+, Xe42+, Kr26+ and Ar16+ ion beams were accelerated. The resonant stochastic extraction (RF knockout technique) was realized. The complex is now used for fixed target experiments with extracted beams and experiments with an internal target. In the near future, the Nuclotron will be the main synchrotron of the NICA collider facility being constructed at JINR. The installation in the Nuclotron of beam injection system from the Booster and of the fast extraction system in the Collider are required for its operation in the NICA complex. In the frame of the Nuclotron injection chain upgrade, a new light ion linac (LILac) for protons and ions will be built.  
slides icon Slides THXXPLM1 [10.806 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THXXPLM1  
About • paper received ※ 29 April 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
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THXXPLM2 Demonstration of Loss Reduction Using a Thin Bent Crystal to Shadow an Electrostatic Septum During Resonant Slow Extraction operation, septum, optics, experiment 3399
 
  • F.M. Velotti, P. Bestmann, M.E.J. Butcher, M. Calviani, M. Di Castro, M. Donzé, L.S. Esposito, M.A. Fraser, M. Garattini, S.S. Gilardoni, B. Goddard, V. Kain, J. Lendaro, A. Masi, D. Mirarchi, M. Pari, J. Prieto, S. Redaelli, R. Rossi, W. Scandale, R. Seidenbinder, P. Serrano Galvez, L.S. Stoel, C. Zamantzas, V. Zhovkovska
    CERN, Meyrin, Switzerland
  • F.M. Addesa, F. Iacoangeli
    INFN-Roma, Roma, Italy
  • A.G. Afonin, Y.A. Chesnokov, A.A. Durum, V.A. Maisheev, Yu.E. Sandomirskiy, A.A. Yanovich
    IHEP, Moscow Region, Russia
  • J.E. Borg, M. Garattini, G. Hall, T. James, M. Pesaresi
    Imperial College of Science and Technology, Department of Physics, London, United Kingdom
  • A.S. Denisov, Y. Gavrikov, Yu.M. Ivanov, M.A. Koznov, L.G. Malyarenko, V. Skorobogatov
    PNPI, Gatchina, Leningrad District, Russia
  • F. Galluccio
    INFN-Napoli, Napoli, Italy
  • F. Murtas
    INFN/LNF, Frascati, Italy
 
  A proof-of-principle experiment demonstrating the feasibility of using a thin, bent crystal aligned upstream of an extraction septum (ES) to increase the efficiency of the third-integer resonant slow extraction process has been carried out at the CERN Super Proton Synchrotron (SPS). With the primary aim of reducing the beam loss and induced radio-activation of the SPS, the crystal was aligned to both the beam and the septum to reduce by up to 40% the beam intensity impinging the ES and increase the intensity entering the external transfer line. In this contribution, we introduce the concept and the prototype system that was installed in 2018 before reporting in detail on the dedicated program of machine development studies carried out to characterise its performance and demonstrate operational feasibility. The performance reach and compatibility with other loss reduction techniques proposed to further increase the extraction efficiency, such as phase space folding with octupoles, is discussed in view of future high intensity operation.  
slides icon Slides THXXPLM2 [1.397 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THXXPLM2  
About • paper received ※ 15 May 2019       paper accepted ※ 28 May 2019       issue date ※ 21 June 2019  
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THXXPLS1 Status of the Carbon Commissioning and Roadmap Projects of the MedAustron Ion Therapy Center Accelerator proton, MMI, synchrotron, injection 3404
 
  • M.T.F. Pivi, L. Adler, A. De Franco, F. Farinon, N. Gambino, G. Guidoboni, G. Kowarik, M. Kronberger, C. Kurfürst, H.T. Lau, S. Myalski, S. Nowak, C. Schmitzer, I. Strašík, P. Urschütz, A. Wastl
    EBG MedAustron, Wr. Neustadt, Austria
  • L.C. Penescu
    Abstract Landscapes, Montpellier, France
 
  The synchrotron-based MedAustron Particle Therapy Accelerator MAPTA located in Austria, delivers proton beams for medical treatment in the energy range 62-252 MeV/n since the year 2016 and is in preparation to provide C6+ carbon ions in the range 120-400 MeV/n to two of the three clinically used ion therapy irradiation rooms. In addition, carbon and proton beams, the latter with up to 800 MeV, will be provided to a fourth room dedicated to research. After beam generation and pre-acceleration to 7MeV, a 77m long synchrotron accelerates particles up to the requested energy for clinical treatment. A third-order resonance extraction method is used to extract the particles from the synchrotron in a slow controlled process and then transfer the particles to the 4 irradiation rooms with a spill time of 0.1-10 seconds to facilitate the control of the delivered radiation dose during clinical treatments. Presently, proton beams are delivered to the horizontal and vertical beam lines of three rooms. Commissioning of the accelerator with carbon ions has been completed for one beam line. In parallel, the installation of the beam line magnets for the proton Gantry is ongoing. A review of the accelerator and the status of the carbon commissioning, ongoing in parallel with clinical operations, and an outlook to future roadmap projects are presented.  
slides icon Slides THXXPLS1 [17.863 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THXXPLS1  
About • paper received ※ 19 May 2019       paper accepted ※ 24 May 2019       issue date ※ 21 June 2019  
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THPMP010 Implementation of RF-KO Extraction at CNAO betatron, synchrotron, kicker, resonance 3469
 
  • S. Savazzi, E. Bressi, G. Debernardi, L. Falbo, V. Lante, C. Priano, M. G. Pullia
    CNAO Foundation, Pavia, Italy
  • P. Meliga
    University of Pavia, Pavia, Italy
  • G. Russo
    Politecnico di Torino, Torino, Italy
 
  The National Centre for Oncological Hadrontherapy (CNAO) is a synchrotron based particle therapy facility. Both protons and carbon ions can be used for treatments. The main extraction system is based on ’amplitude-momentum selection’ driven by a betatron core, but RF-KO (Radio-Frequency Knock Out) is being implemented as an alternative extraction scheme, being more suitable for a future implementation of a ’multi energy extraction’ operation of the accelerator. With a double extraction possibility, CNAO would allow an interesting theoretical and experimental evaluation of the relative merits of the two extraction schemes. The RF deflector is already installed and the RF power generation is under commissioning. Extraction simulations and first results of the system are presented.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPMP010  
About • paper received ※ 15 May 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019  
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THPMP029 Design Study of a Compact Superconducting Cyclotron SC240 for Proton Therapy cyclotron, proton, focusing, superconducting-magnet 3506
 
  • F. Jiang, G. Chen, Y. Chen, K.Z. Ding, J. Li, Y. Song, Z. Wu, J. Zhou
    ASIPP, Hefei, People’s Republic of China
  • Z. Zhong
    HFCIM, HeFei, People’s Republic of China
 
  Funding: National Natural Science Foundation of China under grant No. 11775258 & 11575237; International Scientific and Technological Co-operation Project of Anhui (grant No. 1704e1002207).
A compact AVF cyclotron of 240 MeV is under-designed for proton therapy. In order to reduce the size, the weight and operation cost, two superconducting coils are designed to implement the 2.35T central field. And the magnet weight is about 90 tons. The constant gap between the sectors is considered without deteriorating the beam stability. A dedicated design on extraction zone is performed to make the average field to close the isochronous field. The extraction efficiency is expected higher than 80%, by regulating the 1st harmonic field and arranging the extraction elements properly. In order to avoid the large scale of volume helium explosion in the quench, the low temperature superconducting coil using NbTi/Cu wire is cooled by 4K GM Cryocooler in a helium volume limiting design. The paper will present the physical design of this cyclotron.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPMP029  
About • paper received ※ 17 May 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
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THPMP051 Development of 211-Astatine Production in the Crocker Nuclear Laboratory Cyclotron target, cyclotron, operation, proton 3564
 
  • E. Prebys
    Fermilab, Batavia, Illinois, USA
  • R.J. Abergel
    UCB, Berkeley, California, USA
  • W.H. Casey
    University of California at Davis (UC Davis), Davis, California, USA
  • D.A. Cebra
    UCD, Davis, California, USA
 
  There is a great deal of interest in the medical community in the use of the alpha-emitter 211-At as a therapeutic isotope. Among other things, its 7.2 hour half life is long enough to allow for recovery and labeling, but short enough to avoid long term activity in patients. Unfortunately, the only practical technique for its production is to bombard a 209-Bi target with a ~29 MeV alpha beam, so it is not accessible to commercial isotope production facilities, which all use fixed energy proton beams. The US Department of Energy is therefore supporting the development of a "University Isotope Network" (UIN) to satisfy this need. Our prposoal is to retrofit the variable-energy, multi-species cyclotron at the Crocker Nuclear Laboratory at the University of California Davis with an internal Bi-209 target, such that we can put at least 100 uA of 29 MeV alpha particles on target without concerns about extraction efficiency. Using very conservative assumptions, we are confident we will be able to produce 60 mCi of 211-At in solution in an eight hour shift, which includes setup, exposure, and chemical recovery. This poster will cover the design of the target, as well as the required chemical processing and reliability upgrades.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPMP051  
About • paper received ※ 15 May 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
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THPRB036 Development of Injection and Extraction Kickers for SuperKEKB Damping Ring kicker, injection, power-supply, damping 3890
 
  • M. Tawada, M. Kikuchi, Y. Sakamoto, H. Someya
    KEK, Ibaraki, Japan
  • K. Tenjin, A. Tokuchi
    Pulsed Power Japan Laboratory Ltd., Kusatsu-shi Shiga, Japan
 
  SuperKEKB is a double ring asymmetric collider to study the B meson physics, which is an upgrade project of KEKB. The 7 GeV electron (HER) and the 4 GeV positron ring (LER) collides at an interaction point. The positron beam produced by linac cannot meet the dynamic aperture restrictions of LER. Damping ring (DR) is required to reduce its injection emittance. Damping ring (DR) for SuperKEKB has two kicker magnets for the injection and the extraction, respectively. These kickers are required to meet the following specifications: (1) rise and fall time does not exceed 100 ns, (2) two bunches which are 96 ns apart must be kicked by single pulse, (3) the stability of peak current for the extraction kickers must be less than 0.1 %. Kicker magnets are designed as a conventional kicker with a ferrite core. The pulse shape is a double half sine for the two bunch injection. In order to achieve short rise time, a saturable inductance is used. The design and performance of kicker magnets and the power supplies are reported.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPRB036  
About • paper received ※ 15 May 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
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THPRB037 Improved Frequency Characteristics Using Multiple Stripline Kickers kicker, feedback, controls, pick-up 3893
 
  • T. Toyama, A. Kobayashi, H. Kuboki, M. Okada
    KEK, Tokai, Ibaraki, Japan
 
  One of the important ingredient in the intra-bunch transverse feedback is a kicker. The frequency characteristics of the kicker suffers from the transit-time factor, sin(kl)/kl. We examine the frequency characteristics of multiple kickers system. Relation between the excitation patterns of the multiple kickers and the frequency characteristics are presented.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPRB037  
About • paper received ※ 23 May 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
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THPRB067 Time Varying RF Phase Noise for Longitudinal Emittance Blow-Up synchrotron, emittance, operation, proton 3954
 
  • S.C.P. Albright
    CERN, Geneva, Switzerland
  • D. Quartullo
    Sapienza University of Rome, Rome, Italy
 
  RF phase noise was shown to be effective for controlled longitudinal emittance blow-up in the Proton Synchrotron Booster (PSB) at CERN during beam tests in 2017, with further developments in 2018. At CERN, RF phase noise is used operationally in the Super Proton Synchrotron (SPS) and Large Hadron Collider (LHC). In this paper we show that it is suitable for operation with a variety of beam types in the PSB. In the PSB the synchrotron frequency changes by approximately a factor 4 during the 500 ms acceleration ramp, requiring large changes in the frequency band of the noise. During 2018, a new method of calculating the noise parameters has been demonstrated, which gives upper and lower bounds to the noise frequency band that are smoothly varying through the ramp. The new calculation method has been applied to operational beams accelerated in both single and double RF harmonics, the final results are presented here.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPRB067  
About • paper received ※ 29 April 2019       paper accepted ※ 21 May 2019       issue date ※ 21 June 2019  
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THPRB069 The New Digital Low-Level RF System for CERN’s Extra Low Energy Antiproton Machine LLRF, proton, antiproton, operation 3962
 
  • M.E. Angoletta, M. Jaussi, J.C. Molendijk
    CERN, Geneva, Switzerland
 
  CERN’s new Extra Low ENergy Antiproton accelerator/decelerator (ELENA) completed its initial commissioning in 2018. This machine is equipped with a new digital Low-Level RF (LLRF) system that implements beam and cavity loops as well as longitudinal diagnostics. ELENA’s LLRF was instrumental for machine commissioning by decelerating some 1 E7 antiprotons from 5.3 MeV to 100 keV. Commissioning with H ions took also place. Challenges faced included coping with low beam intensity and the wide frequency swing. This paper gives an overview of the LLRF system capabilities and operation. Beam results achieved with both H ions and antiprotons are also shown.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPRB069  
About • paper received ※ 13 May 2019       paper accepted ※ 21 May 2019       issue date ※ 21 June 2019  
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THPRB071 Beam-Based Measurements on Two ±12.5 kV Inductive Adders, together with Striplines, for CLIC Damping Ring Extraction Kickers kicker, flattop, damping, storage-ring 3970
 
  • J. Holma, M.J. Barnes, M. Carlà, N. Catalán Lasheras, Y. Papaphilippou
    CERN, Geneva, Switzerland
  • U. Iriso, Z. Martí, F. Pérez, M. Pont
    ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain
 
  The CLIC study is investigating the technical feasibil-ity of an electron-positron linear collider with high lumi-nosity and a nominal centre-of-mass energy of 3 TeV. Pre-damping rings and damping rings (DRs) will produce ultra-low emittance beam with high bunch charge. The DR kicker systems, each of which consists of a set of striplines and two inductive adders, must provide ex-tremely stable field pulses. The DR extraction kicker system is the most demanding: specifications require a field uniformity within ±0.01% and pulses up to 900 ns flattop duration, at ±12.5 kV and 309 A, with ripple and droop of not more than ±0.02 % (±2.5 V), with respect to a reference waveform. Two prototype inductive adders have been designed and built at CERN, and have been tested with prototype striplines installed in the storage ring of the ALBA Synchrotron Light Source, in Spain. The stability of the kicker system, including the modulators, has been evaluated from the beam-based measure-ments and is reported in this paper.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPRB071  
About • paper received ※ 15 May 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
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THPRB073 Laboratory Measurements on Two ±12.5 kV Inductive Adders with ±0.02% Waveform Stability for CLIC Damping Ring Extraction Kickers kicker, flattop, damping, collider 3978
 
  • J. Holma, M.J. Barnes, A. Chmielinska
    CERN, Geneva, Switzerland
  • M. Pont
    ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain
 
  The CLIC study is investigating the technical feasibil-ity of an electron-positron collider with high luminosity and a nominal centre-of-mass energy of 3 TeV. Pre-damping rings and damping rings (DRs) will produce ultra-low emittance beam with high bunch charge. The DR kicker systems must provide extremely stable field pulses to avoid beam emittance increase. Each DR extrac-tion kicker system consists of a set of striplines and two pulse modulators. Specifications for this system require that the modulator produce pulses of 900 ns flattop dura-tion, ±12.5 kV and 305 A, with ripple and droop of not more than ±0.02 % (±2.5 V) with respect to a reference waveform. Inductive adder topology has been chosen for the pulse modulators. Two full-scale, 20-layer, 12.5 kV prototype inductive adders have been designed, built and tested at CERN. This paper presents the measurements of the stability of these adders for two different waveforms: a flat-top waveform and a controlled decay waveform, the latter of which is required to generate flat-top total field for the CLIC DR extraction stripline kicker.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPRB073  
About • paper received ※ 15 May 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
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THPRB080 Automatisation of the SPS ElectroStatic Septa Alignment alignment, simulation, operation, septum 4001
 
  • S. Hirlaender
    ATI, Vienna, Austria
  • M.A. Fraser, B. Goddard, V. Kain, J. Prieto, L.S. Stoel, F.M. Velotti
    CERN, Geneva, Switzerland
  • M. Szakaly
    Wigner Research Centre for Physics, Institute for Particle and Nuclear Physics, Budapest, Hungary
 
  An electrostatic septum composed of 5 separate tanks is used to slow-extract the 400 GeV proton beam resonantly on the third integer resonance from the CERN SPS. The septa are all mounted on a single support structure that can move the ensemble coherently and, in addition, the internal anode and cathode of each tank can be moved independently. The septum is aligned to the beam by measuring and minimising the induced beam loss signals in the extraction region following an alignment procedure that is usually carried out manually at the beginning of each year. The large number of positional degrees of freedom complicates the procedure and until recently each tank was aligned one after the other semi-manually, typically requiring 8 hours. It is not uncommon that the septum has to be re-aligned later in the run taking time away from physics programme. To tackle this issue, a simplified beam dynamics and scattering simulation routine was developed to permit error studies with a large number of seeds to be carried out in a reasonable computation time. In this contribution, the simulation model will be described before the results of its exploitation to understand the efficacy of alignment procedures based on different optimization algorithms are discussed and compared to the present operational procedure. The effort culminated with the implementation of an automated alignment procedure based on a Powell optimisation algorithm that reduced the time needed to align the septum by over an order of magnitude.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPRB080  
About • paper received ※ 14 May 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
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THPRB096 Real-Time Beam Orbit Stabilisation to 200 Nanometres in Single-Pass Mode Using a High-Precision Dual-Phase Feedback System feedback, collider, electron, real-time 4049
 
  • D.R. Bett, P. Burrows, G.B. Christian, C. Perry, R.L. Ramjiawan
    JAI, Oxford, United Kingdom
 
  A high-resolution, low-latency, stripline beam position monitor (BPM) system has been developed for use at particle accelerators and beamlines that operate with trains of particle bunches with bunch separations as low as several tens of nanoseconds, such as future linear electron-positron colliders and free-electron lasers. The system consists of fast analogue stripline BPM signal processors input to a custom FPGA-based digital feedback board which drives a pair of kickers local to the BPMs and nominally orthogonal in phase in closed-loop feedback mode, thus achieving both beam position and angle stabilisation. The feedback system was tested with the electron beam in the extraction line of the Accelerator Test Facility at the High Energy Accelerator Research Organization (KEK) in Japan. Recent upgrades to the BPMs have increased the single-shot, real-time position resolution of the system to ~150 nm for a beam charge of 1.3 nC. We report the latest results which demonstrate the feedback system operating at this resolution limit and a beam stabilisation performance of 200 nm.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPRB096  
About • paper received ※ 13 May 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
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THPRB113 Concept of Beam-Related Machine Protection for the Future Circular Collider machine-protect, beam-losses, proton, collider 4085
 
  • Y.C. Nie, R. Schmidt, J.A. Uythoven, C. Wiesner, D. Wollmann, M. Zerlauth
    CERN, Meyrin, Switzerland
 
  In the Future Circular Collider (FCC) study, a proton-proton circular collider (FCC-hh) is considered with a stored beam energy 20 times higher than that of the LHC. Any uncontrolled release of such energy could potentially result in severe damage to the accelerator components. Machine protection of the FCC-hh is hence very important and challenging. With a machine-protection strategy similar to the LHC, FCC would require up to three turns to dump the beam synchronously after a failure detection. Due to several possible ultrafast failures, which could lead to significant beam losses in a few turns, it is important to further reduce the reaction time of the machine protection system (MPS) for the FCC. Reducing the detection time of a failure by using faster beam monitors, e.g. diamond detectors, can reduce the time between a beam loss and the beam dump request. Communication delay of the interlock system to the beam dumping system can be reduced by using a more direct signal path. More than one beam-free abort gap will shorten the time required for the synchronization between the abort gap and the extraction kicker. Different failure scenarios are classified according to the speed of the failure onset and the subsequent increase of induced beam losses. The critical failure modes, their potential mitigations and impacts on the design of the MPS are presented.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPRB113  
About • paper received ※ 14 May 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
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THPTS028 Recent Improvements and Future Upgrades of the J-PARC Main Ring Kicker Systems kicker, operation, power-supply, injection 4167
 
  • T. Sugimoto, K. Ishii, H. Matsumoto, T. Shibata
    KEK, Ibaraki, Japan
 
  J-PARC Main Ring provides 500kW proton beam to the long baseline neutrino oscillation experiment (T2K). In order to increase the beam intensity to improve the sensitivity of the CP violation study in neutrino sector, shorter repetition cycle and higher beam current are required. As part of the upgrade project, both injection and fast-extraction (Fx) kicker magnet systems have been improved. Air-cooled non-inductive ceramic resistors are used as the impedance-matching terminator for the injection kicker magnet. Power consumption and temperature rise of the termination resistor due to the beam induced current was simulated to optimize the number of parallel of the resistors. Efficiency of cooling fans was also simulated to improve the cooling ability. For the Fx kicker magnet, a fast charging power supply of the modulator was developed and deployed to shorten the charging period from 1.4 sec to 0.2 sec. This paper represents the simulation results, performance of the charging unit and future upgrade plans.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPTS028  
About • paper received ※ 21 May 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
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THPTS062 Alternative Proposal for FCC-hh Extraction Septa septum, quadrupole, vacuum, simulation 4248
 
  • A. Sanz Ull, M.G. Atanasov, B. Balhan, J.C.C.M. Borburgh
    CERN, Geneva, Switzerland
 
  Challenging requirements are set for the FCC extraction septa magnets, notably for the magnetic field level, the septum thickness and the leak field. An alternative to the baseline FCC extraction layout with normal conducting Lambertson septa is proposed, consisting of a Superconducting Shield (SuShi) stage and a Truncated Cosine theta septa stage with the aim of reducing the necessary number of septa and installed length. The principal parameters of the septa are described and the feasibility discussed. Areas for study improvement are identified.
This paper is intended for publication in the PRAB special edition.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPTS062  
About • paper received ※ 13 May 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
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THPTS063 Development of a W-Band Power Extraction Structure cavity, undulator, electron, GUI 4252
 
  • F. Toufexis, B. J. Angier, D. Gamzina, A. McGuire, M. Shumail, S.G. Tantawi
    SLAC, Menlo Park, California, USA
 
  Funding: This project was funded by U.S. Department of Energy under Contract No. DE-AC02-76SF00515, and the National Science Foundation under Contract No. PHY-1415437.
We are modifying the X-Band Test Accelerator at SLAC to operate as an Extreme Ultra Violet (EUV) light source*. The existing photo electron gun will be replaced by a thermionic X-Band injector which utilizes RF bunch compression. The beam is accelerated up to 129 MeV using an X-Band traveling wave structure followed by a novel high shunt impedance standing wave structure. The beam then goes through a mm-wave undulator with a period of 1.75 mm, producing EUV radiation around 13.5 nm. The undulator is powered by a W-Band decelerator structure, which extracts the RF power from the electron beam. In this work we present the mechanical design and fabrication of the 91.392 GHz decelerator structure, as well as structural characterization of its cavities using SEM and 3D microscopy.
* F. Toufexis, et al, "A Compact EUV Light Source using a mm-wave Undulator", Proceedings of IPAC17.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPTS063  
About • paper received ※ 10 May 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
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FRXXPLS2 Extinction Measurement of J-PARC MR with 8 GeV Proton Beam for the New Muon-to-Electron Conversion Search Experiment - COMET proton, experiment, timing, kicker 4372
 
  • H. Nishiguchi, Y. Fukao, Y. Hashimoto, Y. Igarashi, S. Mihara, M. Moritsu, R. Muto, M. Tomizawa, K. Ueno
    KEK, Tsukuba, Japan
  • Y. Fujii
    Monash University, Faculty of Science, Clayton, Victoria, Australia
  • P. Sarin
    Indian Institute of Technology Bombay, Mumbai, India
  • F. Tamura
    JAEA/J-PARC, Tokai-mura, Japan
 
  Funding: This work is partially supported by JSPS (Japan Society for the Promotion of Science) : KAKENHI 15K13492 and 16H00876
At J-PARC, extraction tests of a 8GeV pulsed proton beam from Main Ring (MR) have been successfully completed by a team drawn from the Accelerator Laboratory Group and the COherent Muon to Electron Transition (COMET) Experimental Group. The COMET Experiment aims to find new physics beyond the Standard Model by searching for the coherent neutrinoless conversion of a muon to an electron in muonic atoms, so-called mu-e conversion. This requires an extremely clean pulsed beam, and development of this beam plays a key role in the pursuit of the highest level of sensitivity. This successful extraction test is the clearing of a major milestone for the forthcoming experiment. The goal of the extraction tests was to confirm the beam quality under the customized MR operation mode. The J-PARC MR usually accelerates the proton beam (at one bunch per 600ns) up to 30GeV. But in the test, the MR instead accelerates the proton beam (at one bunch per 1.2us) up to 8GeV. The number of protons leaking between proton bunches, so-called EXTINCTION, must be less than one for every 1010 protons in the bunch. Extraction tests in the customized mode were conducted in January and February 2018 and resulted in many successes. In this test, leakage protons between bunches was successfully reduced below the objective of 10−10 of the number of protons in a bunch. This is a great success to guarantee the quality of proton beam required by COMET experiment. In addition, the time development of proton leakage was also precisely studied with several RF settings which enables us to further improve the extinction. In this paper, the result of extinction measurement and future prospect of beam extinction improvement is presented in addition to the detailed description of customized MR operation.
 
slides icon Slides FRXXPLS2 [13.427 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-FRXXPLS2  
About • paper received ※ 15 May 2019       paper accepted ※ 21 May 2019       issue date ※ 21 June 2019  
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