Keyword: electron
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MO2A03 Technology Developments for ELI-NP Gamma Beam System laser, gun, linac, vacuum 13
 
  • L. Piersanti, D. Alesini, A. Battisti, M. Bellaveglia, S. Bini, F. Cardelli, R.D. Di Raddo, A. Falone, A. Gallo, V.L. Lollo, L. Pellegrino, S. Pioli, S. Tomassini, A. Variola
    INFN/LNF, Frascati (Roma), Italy
  • N. Beaugerard
    SEIV, Mérignac, France
  • K. Cassou, D. Douillet, K. Dupraz, T. Le Barillec, A. Martens, C.F. Ndiaye, Y. Peinaud, Z.F. Zomer
    LAL, Orsay, France
  • L. Ficcadenti, A. Mostacci, L. Palumbo, V. Pettinacci
    INFN-Roma, Roma, Italy
  • M. Migliorati
    INFN-Roma1, Rome, Italy
  • D.T. Palmer, L. Serafini
    Istituto Nazionale di Fisica Nucleare, Milano, Italy
  • H. Rocipon
    ALSYOM, Argebteuil, France
 
  ELI-NP gamma beam system (GBS) is a linac based gamma-source in construction in Magurele (RO) by the European consortium EuroGammaS led by INFN. Photons with tunable energy, from 0.2 to 19.5 MeV, and with intensity and brilliance beyond the state of the art, will be produced by Compton back-scattering between a high quality electron beam (up to 740 MeV) and an intense laser pulse at 100 Hz repetition rate. Production of very intense photon flux with narrow bandwidth requires multi-bunch operation and laser recirculation at the interaction point. In this paper, the main technological developments carried out by the EuroGammaS consortium for the generation of the ELI-NP gamma beam will be described with a special emphasis on the electron linac technology, such as: RF-gun and C-band accelerating structures design fabrication and tests; low level RF (LLRF) and synchronization systems specifications and development. Finally, the laser recirculation apparatus design is briefly described and first results reported.  
slides icon Slides MO2A03 [9.121 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-MO2A03  
About • paper received ※ 11 September 2018      issue date ※ 18 January 2019  
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MO2A04 Compact SRF Linac for High Brilliance Inverse Compton Scattering Light Source laser, brilliance, emittance, gun 19
 
  • K.E. Deitrick, J.R. Delayen, G.A. Krafft, B. Terzić
    ODU, Norfolk, Virginia, USA
  • J.R. Delayen, G.A. Krafft
    JLab, Newport News, Virginia, USA
 
  New designs for compact SRF linacs can produce micron-size electron beams. These can can be used for inverse Compton scattering light sources of exceptional flux and brilliance.  
slides icon Slides MO2A04 [1.717 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-MO2A04  
About • paper received ※ 12 September 2018      issue date ※ 18 January 2019  
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MOPO005 Commissioning of the Normal Conducting Cavities for LEReC Project cavity, booster, MMI, vacuum 44
 
  • B. P. Xiao, K. Mernick, F. Severino, K.S. Smith, T. Xin, A. Zaltsman
    BNL, Upton, Long Island, New York, USA
 
  Funding: Work is supported by Brookhaven Science Associates, LLC under contract No. DE-AC02-98CH10886 with the US DOE.
To improve RHIC luminosity for heavy ion beam energies below 10 GeV/nucleon, the Low Energy RHIC electron Cooler (LEReC) is designed, and is currently under commissioning at BNL. The linac of LEReC consists of a DC photoemission gun, a 704 MHz superconducting radio frequency (SRF) booster cavity, a three-cell 2.1 GHz third harmonic cavity for RF curvature correction, a single-cell 704 MHz cavity for energy de-chirping and a 704 MHz deflecting cavity for diagnostic line. In this paper, we present the commissioning of three normal conducting cavities mentioned above.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-MOPO005  
About • paper received ※ 14 September 2018      issue date ※ 18 January 2019  
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MOPO007 The Developing of the Beam Injection Section with Laser Source and S-Band Electron RF Gun for SuperKEKB Project laser, gun, MMI, emittance 50
 
  • X. Zhou, Y. Ogawa, M. Yoshida, R. Zhang
    KEK, Ibaraki, Japan
 
  For the beam injection at Linac Accelerator of the SuperKEKB project, the s-band RF gun needs to provide low-emittance high-charge electron bunches. An ultrashort high energy solid laser driving a cathode in a quasi-travelling side-coupled RF gun were developed. A Yb fiber and Nd:YAG hybrid laser amplify system is start with 114.24 MHz oscillator that synchronized from accelerator. Two beam lines with the 25Hz, ~20ps, and sub-mJ Ultraviolet pulses were generated to RF gun. Ir5Ce has long lifetime and quantum efficiency QE that was employed to cathode. The RF gun has two side coupled cavities on same axis can realize quasi-traveling wave, which is suitable for the high charge and low emittance beam generation. Now, great progress has been made to make the RF gun function well. For the Phase II commissioning, required charge and emittance were achieved.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-MOPO007  
About • paper received ※ 05 September 2018      issue date ※ 18 January 2019  
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MOPO008 The RF Gun Adopting the Dielectric Assist Accelerating Structure cavity, cathode, emittance, laser 54
 
  • S. Mori, D. Satoh, M. Yoshida
    KEK, Ibaraki, Japan
 
  We apply the dielectric assist accelerating (DAA) structure to the RF gun, which is a candidate for a high average current and high brightness electron source. The DAA structure consists of ultralow-loss dielectric cylinders and disks which are periodically arranged in a metallic enclosure. Due to the high quality factor and the high shunt impedance of the DAA cavity, the RF gun adopting the DAA cavity can be a high-duty electron beam source at room temperature. We provide design work for RF gun adopting the DAA structure.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-MOPO008  
About • paper received ※ 12 September 2018      issue date ※ 18 January 2019  
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MOPO009 ELI-NP Gamma Beam System - Current Project Status laser, linac, gun, experiment 59
 
  • P.S. Tracz
    IFIN-HH, Bucharest - Magurele, Romania
 
  The Gamma Beam System at the ELI-NP under construction in Magurele/Bucharest Romania, aims at producing high brilliance gamma-rays based on the laser Compton back-scattering, up to 3.5 and 19.5 MeV out of two interaction chambers. The design of warm RF electron linac is optimized to meet the unique source specification i.e. high brilliance, small relative bandwidth, tunable energy, and high spectral density. Together with technological development in field of high energy/high quality lasers it will open new opportunities for nuclear physics research in fields like nuclear photonics, nuclear astrophysics, photo-fission, and production of exotic nuclei, applications in industry, medicine, and space science. S-band laser driven RF photo-gun and two accelerating structures constitute the injector. The beam is then accelerated by C-band linac up to 350MeV (low energy linac), and up to 720MeV (high energy linac). The GBS was designed and is being constructed by the EuroGammaS - a consortium of European academic and research institutions and industrial partners. This paper gives an overview of the facility, describes the main linac systems and summarizes the project status.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-MOPO009  
About • paper received ※ 12 September 2018      issue date ※ 18 January 2019  
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MOPO010 JINR Photocathode Research: Status and Plans cathode, laser, gun, scattering 62
 
  • M.A. Nozdrin, N. Balalykin, J. Huran, V.F. Minashkin, G. Shirkov
    JINR, Dubna, Moscow Region, Russia
  • E. Gacheva, A. Poteomkin, V. Zelenogorsky
    IAP/RAS, Nizhny Novgorod, Russia
  • J. Huran
    Slovak Academy of Sciences, Institute of Electrical Engineering, Bratislava, Slovak Republic
 
  Photocathode research in the frame of the "transmission" photocathode conception (backside illuminated cathode based on a quartz/sapphire plate or a metal mesh which is a substrate for thin film made of a photomaterial) is being conducted in the Veksler and Baldin Laboratory of High Energy physics (LHEP) of the Joint Institute for Nuclear Research (JINR). Status of the 30-kev DC Photogun test bench and recent results of the extremely thin carbon film based cathodes research are described. Progress in the full-scale photoinjector prototype (max electron energy of 400 keV) is given. Startup of the photoinjector was performed, 70 keV electrons were extracted (650 pC).  
poster icon Poster MOPO010 [1.564 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-MOPO010  
About • paper received ※ 11 September 2018      issue date ※ 18 January 2019  
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MOPO016 Narrow-Band Terahertz Generation from Beam Pipe with Helix Wires radiation, wakefield, simulation, impedance 65
 
  • D. Wang
    TUB, Beijing, People’s Republic of China
 
  We studied through analysis and numerical simulations the use of a relativistic electron bunch to drive a metallic beam pipe with helix wire inside, for the purpose of gen-erating narrow-band terahertz radiation. we have shown that the frequency is related to the radius of the pipe and that of the wire, thus one can generate a narrow-band radiation pulse with frequency tunable through this scheme with different pipes and wires. The total energy of a few milli-Joules. The pulse length tends to be on the order of hundreds of picoseconds. We have also shown that, if the pipe radius is tapered along its length, the generated pulse will end up with a frequency chirp.
*wangdan2016@mail.tsinghua.edu.cn
*yanlx@mail.tsinghua.edu.cn
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-MOPO016  
About • paper received ※ 12 September 2018      issue date ※ 18 January 2019  
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MOPO018 Development of an Improved Capture Section for the S-DALINAC Injector* cavity, linac, gun, simulation 68
 
  • S. Weih, M. Arnold, J. Enders, N. Pietralla
    TU Darmstadt, Darmstadt, Germany
  • D.B. Bazyl, H. De Gersem, W.F.O. Müller
    TEMF, TU Darmstadt, Darmstadt, Germany
 
  For the injector of the superconducting Darmstadt electron linear accelerator S-DALINAC, the design of a new capture cavity was recently completed. This beta-reduced structure will optimize the capture of low-energy electron bunches from the gun section and therefore improve the longitudinal beam quality of the injector beam, as simulations have shown. The existing cryomodule of the injector has to be modified for the installation of the new cavity. These modifications include adaptions of the tuner frame as well as modifications of other surrounding parts. To improve the diagnostics in the low-energy section, an energy-spread measurement setup is currently also under development. In this contribution the cryomodule modifications as well as simulation results for the longitudinal beam dynamics are presented.
*Work supported by DFG through GRK 2128 "AccelencE"
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-MOPO018  
About • paper received ※ 12 September 2018      issue date ※ 18 January 2019  
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MOPO020 Beam Dynamics Studies and Instrumentation Tests for Bunch Length Measurements at CLEAR experiment, gun, simulation, radiation 74
 
  • L. Garolfi, M. Bergamaschi, R. Corsini, A. Curcio, S. Döbert, W. Farabolini, D. Gamba, I. Gorgisyan
    CERN, Geneva, Switzerland
  • C. Bruni, P. Lepercq, H. Purwar, C. Vallerand
    LAL, Orsay, France
  • W. Farabolini
    CEA/DSM/IRFU, France
 
  A new CERN Linear Electron Accelerator for Research (named CLEAR) has been installed as a general-purpose user facility to study novel accelerating techniques, high-gradient structures, instrumentation and irradiation experiments. CLEAR is a flexible accelerator that can provide high quality bunched electron beams with a wide range of beam parameters up to an energy of 220 MeV, offering several testing capabilities. Among all the potential applications, novel accelerating techniques, such as plasma acceleration and THz generation are considered. These applications require shorter bunches, down to the 100 fs level. This paper reports on beam dynamics studies and instrumentation tests to establish a bunch length of this order in CLEAR. The short bunches are generated using adiabatic bunching in the first accelerating structure. For bunch length diagnostic CLEAR is equipped with a streak camera and a transverse deflecting cavity. Alternatively a phase-scan of the last accelerating structure could be used as well to estimate the bunch length. The experimental results with respect to these different techniques are presented and compared with simulations.  
slides icon Slides MOPO020 [0.864 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-MOPO020  
About • paper received ※ 12 September 2018      issue date ※ 18 January 2019  
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MOPO024 Development of High Power Coherent Terahertz Wave Sources at Lebra 125 MeV Linac in Nihon University FEL, radiation, linac, undulator 78
 
  • T. Sakai, K. Hayakawa, Y. Hayakawa, K. Nogami, Y. Sumitomo, Y. Takahashi, T. Tanaka
    LEBRA, Funabashi, Japan
  • H. Ogawa, N. Sei
    AIST, Tsukuba, Ibaraki, Japan
 
  Funding: This work was supported by JSPS KAKENHI Grant Number JP16K17539 and JP16H03912.
Research and Development of a high performance electron linac for the generation of FEL, Parametric X-ray Radiation (PXR) and THz waves has been continued at the Laboratory for Electron Beam Research and Application (LEBRA) of Nihon University as a joint research with KEK and National Institute of Advanced Industrial Science and Technology. The transport systems of the THz wave were installed in the vacuum chamber on the downstream side of the bending magnet of the PXR and FEL beam-line. The CER and the CSR are generated by the bending magnet each of the beam line. In addition, the CTR using thin metal foil is also generated. The average power of the CTR wave was measured approximately 1 mJ/macro-pulse (pulse width 4.5 µs) near the CTR wave beam source point in the frequency range of 0.1 - 2.5 THz. In addition, the energy of the CER as high as 0.2 mJ/macro-pulse were achieved with the experimental room. Furthermore, CER of the generated the FEL beam line can also be guided from the bending magnet on the downstream side of the undulator without disturbing the FEL oscillations. THz transport beam-lines and the characteristics of the THz waves are discussed in this report.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-MOPO024  
About • paper received ※ 12 September 2018      issue date ※ 18 January 2019  
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MOPO026 The Resonance Frequency Shift After Applying the Cooling System for a Side Coupled Standing Wave Linac cavity, controls, coupling, resonance 81
 
  • M. Mohseni Kejani, F. Abbasi Davani
    Shahid Beheshti University, Tehran, Iran
  • S. Ahmadiannamin
    ILSF, Tehran, Iran
  • F. Ghasemi
    NSTRI, Tehran, Iran
  • S. Zarei
    Nuclear Science and Technology Research, InstituteRadiation Application School, Tehran, Iran
 
  A radio frequency accelerator tube used in linear medical accelerators includes three main sections of the radio frequency cavity, an electron gun and the X-ray target, which is vacuumed by a pump inside it. The electromagnetic energy loss in the structure of the cavity can increase the temperature of the tube, resulting in changes in the geometric dimensions and then changes in some of the cavity characteristics, such as the resonance frequency. A cooling system is required to prevent excessive change in the resonant frequency due to thermal loss. Also, it is necessary to perform some computer simulations to stabilize the cavity’s performance in the presence of electromagnetic energy thermal dissipation and the cooling system. In this paper, the simulation results of resonant frequency shifts after applying the cooling system have been reported.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-MOPO026  
About • paper received ※ 12 September 2018      issue date ※ 18 January 2019  
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MOPO027 Photocathode Laser Pulse Shaping for Improved Emittance laser, cathode, gun, emittance 84
 
  • M. Kotur, J. Andersson, J. Björklund Svensson, M. Brandin, F. Curbis, L. Isaksson, F. Lindau, R. Lindvall, E. Mansten, R. Svärd, S. Thorin, S. Werin
    MAX IV Laboratory, Lund University, Lund, Sweden
 
  We present a setup for producing and characterizing picosecond ultraviolet laser pulses for use in the MAX IV photocathode electron gun preinjector. Frequency-tripled laser pulses from a commercial laser system are shaped directly in the ultraviolet domain using a Fourier-domain pulse shaper. The pulses were characterized using a transitent grating FROG. We discuss a proposed upgrade of the pulse shaper, as well as its limitations.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-MOPO027  
About • paper received ※ 12 September 2018      issue date ※ 18 January 2019  
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MOPO028 Survey and Alignment System of 100 MeV/100 kW Electron Linear Accelerator quadrupole, target, survey, neutron 87
 
  • O. Bezditko, I.I. Karnaukhov, A.Y. Zelinsky
    NSC/KIPT, Kharkov, Ukraine
 
  For successful operation and working of electron linear accelerator of "NEUTRON SOURCE" driver it is necessary that all the acceleration sections, the quadrupole triplets, the quadrupole lenses, the dipole magnets, the scanning magnets and the chicane should be installed in design position according design parameters. Accuracies of all electromagnetic elements installation are 150 mkm for all three rotation freedom. The whole process, fiducialization and developing of survey net, alignment is controlled by laser tracker Leica AT 401.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-MOPO028  
About • paper received ※ 12 September 2018      issue date ※ 18 January 2019  
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MOPO029 Physics design and dynamic simulation of a C-band photocathode electron gun for UEM gun, emittance, cathode, solenoid 90
 
  • T. Chen, W. Li, Y.J. Pei, Zh. X. Tang
    USTC/NSRL, Hefei, Anhui, People’s Republic of China
 
  For discovering structure at atomic scale and getting more details of chemical material and biological tissue, an ultrafast electron microscopy (UEM) has been developed and applied in plenty of subjects and studies. This paper described a C-band photocathode electron gun which will be working at 5712MHz to produce ultrashort electron beams with better dynamic parameters. The RF gun is using coaxial coupler to decrease the size of the gun and keep better symmetry of the field in the photocathode gun so that the beam emittance and energy spread can be reduce a lot. The photocathode rf gun will be a important part of the ultrafast electron microscopy (UEM). Using CST MWS and superfish code to simulate design the gun. After dynamic simulation, the beam parameters as the following: Energy is of 3MeV, Normal emittance of 0.12mm-mrad in boin direction, energy spread is of 5.8·10-4, which are better enough for an UEM.  
poster icon Poster MOPO029 [3.599 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-MOPO029  
About • paper received ※ 11 September 2018      issue date ※ 18 January 2019  
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MOPO034 Dielectric Waveguide-Based THz Radiator Study for SwissFEL experiment, radiation, FEL, GUI 94
 
  • L. Shi, S. Bettoni, M.M. Dehler, E. Ferrari, B. Hermann, R. Ischebeck, F. Marcellini, S. Reiche, V.G. Thominet
    PSI, Villigen PSI, Switzerland
  • A.K. Mittelbach
    Friedrich-Alexander Universität Erlangen-Nuernberg, University Erlangen-Nuernberg LFTE, Erlangen, Germany
 
  Funding: This project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 701647
THz pulses have many unique properties in terms of radiation matter interaction. In particular their non-ionizing excitation of phonons in matter makes them a preferred pump for pump-probe studies at free electron lasers. In order to enrich the scientific potentials at SwissFEL (Swiss Free Electron Laser), which can provide ultrashort soft and hard X-ray pulses, we plan to build an economic THz radiator in the range of 1-20 THz by passing the spent electron beam through a dielectric lined tube after the electron beam has generated X-rays. These THz pulses will be transported to the photon user station. Since SwissFEL operates with 2 bunches, serving two beamlines, THz from the first bunch can be used at the user station of the second bunch to allow for pump arrival time before the probe. The core of such a THz generation setup is the dielectric lined tube and the relativistic electron beam. This paper reports on the numerical study of these tubes, in terms of mode structure, energy, pulse length etc, which are essential parameters for the pump-probe experiments. These tubes will be fabricated and tested in the near future in the electron beam line for the soft X-ray of SwissFEL.
 
slides icon Slides MOPO034 [1.471 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-MOPO034  
About • paper received ※ 12 September 2018      issue date ※ 18 January 2019  
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MOPO039 Status Update of the Fast Energy Corrector Cavity at FLASH cavity, laser, coupling, free-electron-laser 112
 
  • S. Pfeiffer, J. Branlard, L. Butkowski, M. Hierholzer, M. Hoffmann, K. Honkavaara, H. Schlarb, Ch. Schmidt, S. Schreiber, M. Vogt, J. Zemella
    DESY, Hamburg, Germany
  • M. Fakhari
    CFEL, Hamburg, Germany
 
  Funding: The work is part of EuCARD-2, partly funded by the European Commission, GA 312453.
Linear accelerator facilities driving a free-electron laser require femtosecond precision synchronization between external laser systems and the electron beam. Such high precision is required for pump-probe experiments and also for example for the electron bunch injection into a plasma bubble for laser plasma acceleration. An upgrade of the fast intra-train beam-based feedback system is planned at the Free-Electron Laser FLASH in Hamburg, Germany. This linear accelerator is based on superconducting (SRF) technology operating with pulse trains of maximum 1 MHz bunch repetition rate. Arrival time fluctuations of the electron beam are correctable by introducing small energy modulations prior to the magnetic bunch compressor. This contribution focuses on the design and the characterization of a normal-conducting RF (NRF) cavity with large bandwidth, mandatory to correct fast arrival time fluctuations. The cavity has recently been installed in the FLASH beamline. First measurements with the new cavity will be presented.
 
poster icon Poster MOPO039 [1.884 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-MOPO039  
About • paper received ※ 13 September 2018      issue date ※ 18 January 2019  
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MOPO040 Coherent Synchrotron Radiation Monitor for Microbunching Instability in XFEL radiation, laser, bunching, FEL 115
 
  • J.H. Ko, I.S. Ko
    POSTECH, Pohang, Kyungbuk, Republic of Korea
  • H.-S. Kang, C. Kim, G. Kim
    PAL, Pohang, Kyungbuk, Republic of Korea
 
  The microbunching instability is an important issue in an X-ray Free Electron Laser (XFEL). The intensity of the FEL can be reduced significantly by the microbunching instability so that the laser heater is widely used to reduce it. In the X-ray Free Electron Laser of the Pohang Accelerator Laboratory (PAL-XFEL), to directly monitor the microbunching instability, a visible CCD camera was included into the coherent radiation monitor (CRM) which uses a pyroelectric detector. It enabled us to measure the microbunching instability more clearly and optimize the FEL lasing in the PAL-XFEL.  
slides icon Slides MOPO040 [1.125 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-MOPO040  
About • paper received ※ 11 September 2018      issue date ※ 18 January 2019  
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MOPO042 Evolutionary Many-objective Optimization Algorithm for Large-bandwidth Free-Electron-Laser Generation FEL, laser, free-electron-laser, linac 121
 
  • J.W. Yan, H.X. Deng
    SINAP, Shanghai, People’s Republic of China
 
  Funding: National Natural Science Foundation of China , the National Key Research and Development Program of China, the Young Elite Scientist Sponsorship Program by CAST and Ten Thousand Talent Program.
X-ray free-electron lasers (XFELs) are leading-edge instruments in a wide range of research fields. Besides pursuing narrow bandwidth FEL pulses, the large-bandwidth XFEL pulses are very useful in various spectroscopy experiments, multi-wavelength anomalous diffraction, and X-ray crystallography. Overcompression operation scheme can be utilized to generate electron beams with large energy chirp which is benefit for bandwidth broadening. Recently, an evolutionary many-objective (having four or more objectives) algorithm, NSGA-III, was used to optimize the electron beam parameters in the overcompression including energy chirp, energy spread, current profile, peak current, and projected emittance. In this paper, combining with the Xie’s semianalytical estimate formula, the NSGA-III is utilized to find an optimal working point of linac by optimizing the XFEL pulse properties directly. Start-to-end numerical simulations based on the Shanghai soft X-ray Free-Electron Laser user facility parameters demonstrate that a full bandwidth of 4.75% can be generated.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-MOPO042  
About • paper received ※ 12 September 2018      issue date ※ 18 January 2019  
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MOPO058 Industrial Electron Linear Accelerator R&D in CIAE gun, radiation, linac, controls 124
 
  • J.H. Yang, Y. Yang, G. Yu, Z.Q. Zeng
    CIAE, Beijing, People’s Republic of China
  • Z.B. Zhu
    China Institute of Atomic Energy, Beijing, People’s Republic of China
 
  Electron linear accelerator(E-LINAC)is a vital accelerator type for accelerator applications, which widely applied in industry, agriculture and medical industry. The paper introduces R&D of industrial E-LINAC in China Institute of Atomic Energy (CIAE) , including electron gun, modulator, accelerating tube, assembling and testing. Based on these R&D results, the GT series for non-destructive testing(NDT) and FZ series for irradiation processing are developed successfully. At present these E-LINACs play important roles in pressure vessel inspection, food preservation, sterilization and material modification, promoting the E-LINACs application as well as economic development in China.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-MOPO058  
About • paper received ※ 11 September 2018      issue date ※ 18 January 2019  
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MOPO060 Linacs for Industry, Cargo Inspection and Medicine Designed by Moscow University controls, radiation, klystron, operation 130
 
  • A.N. Ermakov, A.S. Alimov, A.N. Kamanin, V.V. Khankin, L. Ovchinnikova, N.I. Pakhomov, N.V. Shvedunov, V.I. Shvedunov, D.S. Yurov
    SINP MSU, Moscow, Russia
  • A.S. Alimov, A.N. Ermakov, V.V. Khankin, L. Ovchinnikova, N.I. Pakhomov, N.V. Shvedunov, V.I. Shvedunov, A.S. Simonov
    LEA MSU, Moscow, Russia
  • I.V. Shvedunov
    Federal State Unitary Enterprise, Laboratory of Electron Accelerators MSU, Ltd, Moscow, Russia
 
  Funding: Work supported in part by Ministry of Education and Science of Russia Grant # RFMEFI58217X0011
The report presents the results of development of applied linear electron accelerators with an energy of up to 10 MeV, performed by the Laboratory of Electron Accelerators MSU. We describe linear accelerators for mobile, stationary and train cargo inspection systems with interlaced energies and pulse repetition rate up to 2 kHz, accelerators for radiography, a sterilization accelerator with beam parameters that are adjustable over a wide range, and an accelerator for a radiotherapy complex.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-MOPO060  
About • paper received ※ 10 September 2018      issue date ※ 18 January 2019  
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MOPO061 Beam Parameters Measurement of C-band 6 MeV Linear Electron Accelerator gun, controls, radiation, klystron 133
 
  • D.S. Yurov, A.S. Alimov, A.N. Ermakov, V.V. Khankin, N.V. Shvedunov, V.I. Shvedunov
    SINP MSU, Moscow, Russia
  • L. Ovchinnikova
    Laboratory of Electron Accelerators MSU, Ltd, Physics Department, Lomonosov Moscow State University, Moscow, Russia
  • A.S. Simonov
    LEA MSU, Moscow, Russia
 
  The new linear electron accelerator with beam energy varied in the range of 2-6 MeV with dual-energy option has been designed by Laboratory of Electron Accelerators MSU Ltd. Linac is based on compact high gradient stand-ing wave C-band accelerating structure fed by multi-beam klystron and is used in the cargo inspection and cancer therapy complexes. In the report, we present the results of electron beam parameters measurements at special stand.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-MOPO061  
About • paper received ※ 10 September 2018      issue date ※ 18 January 2019  
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MOPO062 Linear Electron Accelerator for Radiation Technologies with Beam Parameters Varied in a Wide Range operation, radiation, controls, gun 136
 
  • V.V. Khankin, A.S. Alimov, A.N. Ermakov, A.N. Kamanin, A. Kurilik, N.I. Pakhomov, N.V. Shvedunov, V.I. Shvedunov, D.S. Yurov
    SINP MSU, Moscow, Russia
  • A. Kurilik
    LEA MSU, Moscow, Russia
  • I.V. Shvedunov, A.S. Simonov
    Federal State Unitary Enterprise, Laboratory of Electron Accelerators MSU, Ltd, Moscow, Russia
 
  We present the overview and beam parameters measurements results as well as the operational experience with the S-band pulsed linear electron accelerator with beam energy in the range of 5-10 MeV and maximum beam power of up to 15 kW. The possibility of adjusting the beam parameters in a wide range, provided by the design and control system of the accelerator, allows to use the accelerator in a wide variety of radiation technologies.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-MOPO062  
About • paper received ※ 07 September 2018      issue date ※ 18 January 2019  
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MOPO063 Development of Side-coupled X-band Medical Linear Accelerator for Radiotherapy cavity, linac, gun, target 139
 
  • Y.S. Lee, Y.W. Choi, G.J. Kim, I.S. Kim, J.I. Kim, S. Kim, J.H. Lee
    KERI, Changwon, Republic of Korea
  • J.H. Hwang, Y.N. Kang, A.R. Kim, J.N. Kim, T.G. Oh, Y.A. Oh, Y. J. Seol, J.S. Shin
    The Catholic University of Korea, Seoul, Republic of Korea
 
  Recently, LINAC-based radiotherapy equipment are being developed by combining with imaging devices such as CT or MRI, so that it is possible to precisely focus high dose radiation on tumor tissues while minimizing the normal tissue damage. In order to place the diagnostic and treatment devices simultaneously in a confined space, constraints related to interference and volume between the subsystems must be considered. To meet these requirements, the size and weight of the LINAC system need to be reduced, which can be achieved by applying X-band technology. For the purpose of use in IMRT based on image guided radiotherapy, we developed a 9.3 GHz X-band medical LINAC using side-coupled structure. The LINAC is designed to have the accelerating field strength of 16.8 MV/m, and the beam current transmission efficiency of 26 % at the end of accelerating cell when the supplied RF power is at 1.7 MW. Therefore, it can accelerate the electron beam up to 6.2 MeV with having about 90 mA beam current. We plan to carry out the performance test using beam diagnostics system and X-ray measurement system, and the details of design and experimental results of LINAC will be described in this paper.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-MOPO063  
About • paper received ※ 12 September 2018      issue date ※ 18 January 2019  
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MOPO069 Nuclear and Mechanical Basic Design of Target for Mo-99 Production Using High Power Electron Linac target, photon, neutron, linac 148
 
  • A. Taghibi Khotbeh-Sara, F. Rahmani
    KNTU, Tehran, Iran
  • F. Ghasemi
    NSTRI, Tehran, Iran
  • H. Khalafi
    AEOI, Tehran, Iran
  • M. Mohseni Kejani
    Shahid Beheshti University, Tehran, Iran
 
  Today providing enough supplies of 99mTc / 99Mo as a high usage radioisotope in diagnostic nuclear medicine for the world demand is a big challenge. One of the proofed ways to access reliable source of this radioisotopes is production using e-LINAC [1]. In this investigation it was tried to find the simple and the optimized design of 99Mo production target based on photoneutron reaction using e-LINAC. Based on the Monte-Carlo calculation for radiation transport and finite element thermal analysis, 9 thin plates of enriched 100Mo was suggested. Equal distance between plates was considered for cooling to prevent target melting. The main target includes only 100Mo in one-stage approach method to increase production rate in compare with two-stage approach [2]. Applying 2.5 m/s for inlet velocity of cooling water provides suitable cooling process with maximum temperature of target about 900 ˚C.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-MOPO069  
About • paper received ※ 12 September 2018      issue date ※ 18 January 2019  
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MOPO070 Construction of the Side-coupled Standing-wave e-Linac cavity, simulation, linac, coupling 151
 
  • S. Zarei
    Nuclear Science and Technology Research, InstituteRadiation Application School, Tehran, Iran
  • F. Abbasi
    Shahid Beheshti University, Tehran, Iran
  • M. Bahrami, M. Lamehi
    IPM, Tehran, Iran
  • F. Ghasemi
    NSTRI, Tehran, Iran
 
  Due to Iran’s growing need for accelerators in various applications, NSTRI electron linear accelerator project has been defined for medical and inspection applications. This accelerator is a 6 MeV side-coupled standing-wave that operate is π /2 mode in the frequency of 2998.5 MHz. In this paper the construction and measurement results of the tube of this accelerator are presented. The prototype tube was constructed from aluminum and was clamped with bolts. By using a network analyzer, electric and magnetic probes and a side-coupled cavity tuning method and a bead-pull measurement technique, RF measurements were carried out. The resonant frequency and quality factor have been achieved 2998.5 MHz and 7940 respectively .
low-energy accelerator, construction of linac, standing-wave linac
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-MOPO070  
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MOPO073 Coherent Edge Radiation Sources in Linac-Based Infrared Free-Electron Laser Facilities FEL, radiation, undulator, cavity 154
 
  • N. Sei, H. Ogawa
    AIST, Tsukuba, Ibaraki, Japan
  • K. Hayakawa, Y. Hayakawa, K. Nogami, T. Sakai, Y. Sumitomo, T. Tanaka
    LEBRA, Funabashi, Japan
  • H. Ohgaki, H. Zen
    Kyoto University, Kyoto, Japan
 
  Funding: This study was financially supported by JSPS KAKENHI Grant Number JP16H03912.
National Institute of Advanced Industrial Science and Technology has been studied far-infrared coherent radiation at Linac-based infrared free-electron laser (FEL) facilities in col-laboration with Nihon University and Kyoto University. To obtain high FEL gain at Laboratory for Electron Beam Research and Application (LEBRA) in Nihon University and at Kyoto Uni-versity Free Electron Laser (KU-FEL), the electron-bunch length is compressed to less than 1 ps in their undulator sections. Short electron bunches are suitable for generating intense coher-ent radiation, and we have already developed some terahertz-wave sources based on the coher-ent synchrotron radiation and the coherent transition radiation [1-3]. However, it was difficult to observe them with sufficient intensity without disturbing the infrared FEL oscillations. Then, we now develop coherent edge radiation emitted from downstream bending magnets in the un-dulator sections. It can be extracted from the undulator sections without disturbing the FEL os-cillations. In this presentation, the observed coherent radiation at LEBRA and KU-FEL will be reported on.
[1] N. Sei et al., J. Phys. D: Appl. Phys. 46, (2013) 045104.
[2] N. Sei et al., Nucl. Instr. and Meth. A, 832, (2016) 208.
[3] N. Sei et al., Jpn. J. Appl. Phys.: 56, (2017) 032401.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-MOPO073  
About • paper received ※ 29 August 2018      issue date ※ 18 January 2019  
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MOPO076 Study on Generation of Variable Polarized Coherent THz Radiation Using a Crossed Undulator undulator, radiation, polarization, controls 157
 
  • H. Saito, H. Hama, F. Hinode, K. Kanomata, S. Kashiwagi, S. Miura, T. Muto, I. Nagasawa, K. Nanbu, S. Ninomiya, K. Takahashi
    Tohoku University, Research Center for Electron Photon Science, Sendai, Japan
 
  A variable polarized THz radiation source using a crossed undulator system has been developed at Tohoku University. In this scheme, two coherent undulator radiations from an extremely short electron bunch are used to control the polarization. They are linearly polarized radiations orthogonal to each other. Polarization of superimposed radiation is controlled by adjusting a relative phase between them. A compact planar undulator with seven periods has been designed for an experiment at our facility. The radiation frequency is 2.06 THz for electron beam energy of 22 MeV. The opening angle of the crossed undulator radiation was estimated to be 34 mrad (FWHM). Since the polarization state of the crossed undulator depends on observation angle, its angular dependence was evaluated. It was found that ideal polarization control is realized only in the angle range of 2.5 mrad, which is quite smaller than that of the radiation itself.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-MOPO076  
About • paper received ※ 11 September 2018      issue date ※ 18 January 2019  
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MOPO118 Optimized Design for a Compact Linac with Collinear Absorbing Loads at the Hust FEL-THz cavity, linac, FEL, radiation 242
 
  • J. Jiang, G. Feng, T. Hu, Y. Lu, X.D. Tu, Y.Q. Xiong
    HUST, Wuhan, People’s Republic of China
  • Y.J. Pei
    USTC/NSRL, Hefei, Anhui, People’s Republic of China
 
  To meet the requirement of miniaturization for high power THz radiation in the field of commercial and civil use, RF Linacs have been applied widely as beam injectors, and the Linac with collinear absorbing loads reveals the potential to achieve a tradeoff between performance and compactness. Under overall consideration of systematic conflicts, optimization choices for such Linacs involving power absorbing ability, accelerating efficiency, as well as beamline length were described in this context. Meanwhile, cold testing has been conducted to verify design parameters for the collinear absorbing loads. Furthermore, elaborated calculation of thermal power loss and integrated helical water channel cooling has been performed for the 14MeV Linac with collinear absorbing loads installed on the HUST FEL-THz, and online experiments demonstrated that both the accelerating efficiency and the water cooling performance fulfilled operation demands.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-MOPO118  
About • paper received ※ 11 September 2018      issue date ※ 18 January 2019  
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MOPO121 Large-Scale Optical Synchronization System of the European XFEL laser, FEL, timing, experiment 253
 
  • J.M. Müller, M. Felber, T. Kozak, T. Lamb, H. Schlarb, S. Schulz, C. Sydlo, M. Titberidze, F. Zummack
    DESY, Hamburg, Germany
 
  At the European XFEL, a facility-wide optical synchronization system providing a femtosecond-stable timing reference at more than 40 end-stations had been developed and installed. The system is based on an ultra-stable, low-noise laser oscillator, whose signals are distributed via actively length-stabilized optical fibers to the different locations across the accelerator and experimental areas. There, it is used to locally re-synchronize radio frequency signals, to precisely measure the arrival time of the electron beam for fast beam-based feedbacks, and to phase-lock optical laser systems for electron bunch generation, beam diagnostics and user pump-probe experiments with femtosecond temporal resolution. In this paper, we present the system’s architecture and discuss design choices to realize an extensible, large-scale synchronization infrastructure for accelerators that meets reliability, maintainability as well as the performance requirements. Furthermore, the latest performance result of an all-optically synchronized laser oscillator is shown.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-MOPO121  
About • paper received ※ 12 September 2018      issue date ※ 18 January 2019  
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TU1A03 Status and Issues (Microphonics, LFD, MPS) with TRIUMF ARIEL e-Linac Commissioning cavity, linac, TRIUMF, MMI 286
 
  • S.R. Koscielniak, M. Alcorta, F. Ames, E. Chapman, K. Fong, B. Humphries, O.K. Kester, D. Kishi, R.E. Laxdal, Y. Ma, T. Planche, M. Rowe, S.D. Rädel, V.A. Verzilov, Z.Y. Yao
    TRIUMF, Vancouver, Canada
 
  The ARIEL electron linac (e-linac) is designed to generate cw beams of up to 30 MeV and 10 mA for delivery to a photo-convertor. Bremsstrahlung induced fission of a production target yields neutron-rich rare isotope beams to be supplied to the ISAC experimental facilities. The beam power will eventually reach 300 kW, and a machine protection system (MPS) with 10 μs rapidity is essential. The e-linac, which adopts 1.3 GHz, 2K SRF technology, is composed of a 10 MeV single-cavity injector cryomodule (EINJ) and a 20 MeV two-cavity accelerator cryomodule (EACA). The latter has vector-sum control of two cavities driven from a single klystron. Beam commissioning of these systems is ongoing since 2016. The magnetic optics and MPS commissioning to 10 MeV is reported herein. Beam has been accelerated up to 25 MeV, and thread-ed to the high energy dump (EHD). A campaign to investigate microphonics driving terms, LN2 disturb-ances, and a ponderomotive instability in the EACA, is underway.  
slides icon Slides TU1A03 [9.683 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-TU1A03  
About • paper received ※ 17 September 2018      issue date ※ 18 January 2019  
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TU1P01 Extreme High Brightness Electron Beam Generation in a Space Charge Regime cavity, emittance, space-charge, bunching 314
 
  • A. Bacci
    Istituto Nazionale di Fisica Nucleare, Milano, Italy
  • L. Faillace, M. Rossetti Conti
    Universita’ degli Studi di Milano & INFN, Milano, Italy
 
  The generation of ultra-short, low emittance and low energy spread electron bunches is nowadays a critical requirement for accelerators in plasma wave or for femto-second light sources. A new longitudinal compression scheme, based on velocity and ballistic bunching tech-niques in presence of space charge forces, allows to enter in a peculiar regime, so-called laminar bunching (LB). In this regime, the bunch is longitudinally compressed, at the expense of its transverse size, and the over-bunching is forbidden by the laminarity: going to the minimal longi-tudinal dimension the bunch is adiabatically frozen and transversally refocused. Furthermore this technique heats slightly the uncorrelated energy spread resulting in elec-tron distributions that, in case of bending paths, does not require Laser Heater devices.  
slides icon Slides TU1P01 [1.720 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-TU1P01  
About • paper received ※ 12 September 2018      issue date ※ 18 January 2019  
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TUPO001 About the Limits for the Accelerated Beam Current in the LUE-200 Linac of the IREN Facility klystron, linac, acceleration, neutron 320
 
  • A.P. Sumbaev
    JINR, Dubna, Moscow Region, Russia
  • A.M. Barnyakov, A.E. Levichev
    BINP SB RAS, Novosibirsk, Russia
 
  The beam current loading of the accelerating fields is discussed for the linear accelerator LUE-200 of IREN facility. LUE-200 electron Linac consits of two disk loaded travelling wave accelerating structure with the operating frequency of 2856 MHz and power compression SLED-type system. The limits by the accelerated beam current are defined for different pulse durations of the beam current and RF power. The calculated results are discussed and compared with the measurements.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-TUPO001  
About • paper received ※ 12 September 2018      issue date ※ 18 January 2019  
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TUPO002 Electron Gun for 100 MeV / 100 kW Linear Accelerator of Electrons as the Driver of Nuclear Subcritical Assembly Neutron Source gun, neutron, cathode, controls 323
 
  • M. Moisieienko, O. Bezditko, A. Mytsykov, A.Y. Zelinsky
    NSC/KIPT, Kharkov, Ukraine
 
  100 MeV / 100 kW linear electron accelerator of The "neutron source" nuclear subcritical assembly uses the 120 KW triode electron gun as the primary source of electrons. The gun is designed, manufactured and tested at IHEP, Beijing, China. At present, the gun is installed, tested. The maximum impulse current of the gun equal to 2 A. Under design operation, the impulse current of the gun equal to 0.55 A.The report describes the construction of a 120 kV triode electron gun, the results of testing and test operation.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-TUPO002  
About • paper received ※ 12 September 2018      issue date ※ 18 January 2019  
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TUPO036 Vertical Test Results of Plasma In-situ Cleaning on Low Beta HWR Cavity plasma, cavity, experiment, SRF 408
 
  • A.D. Wu, H. Guo, Y. He, C.F. Hu, S.C. Huang, C.L. Li, Y.M. Li, X. Liu, F. Pan, Y.K. Song, P.R. Xiong, L. Yang, W.M. Yue, C. Zhang, S.H. Zhang, H.W. Zhao
    IMP/CAS, Lanzhou, People’s Republic of China
 
  Field emission occurred in SRF cavity is the major limitation to operate at high gradient with stability. The plasma in-situ cleaning for the low beta HWR cavity was carried out to remove the hydrocarbons contaminants on the inner cavity surface. And the vertical test results indicated that the field emission effect was relieved with the increasing of the quench point and emission set-on point. Thus, oxygen active plasma processing can be an effective method to solve the field emission issues for the low beta HWR cavity.  
slides icon Slides TUPO036 [1.281 MB]  
poster icon Poster TUPO036 [0.672 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-TUPO036  
About • paper received ※ 11 September 2018      issue date ※ 18 January 2019  
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TUPO051 Design Considerations of a Balloon-shaped SSR Superconducting Cavity cavity, simulation, distributed, multipactoring 448
 
  • H.J. Cha, S.W. Jang, E.-S. Kim, K.R. Kim, S. H. Park, J.Y. Yoon
    Korea University Sejong Campus, Sejong, Republic of Korea
 
  A single spoke resonator (SSR, β = 0.51 and f = 325 MHz) is being developed at Korea University. It is well-known that a traditional spoke cavity having flat or round end walls has broad multipacting ranges in acceleration gradient, sometimes including operation region. In general, quite long conditioning time is consumed to overcome such multipacting barriers. In this study, we introduce a balloon-shaped SSR superconducting cavity for the multipacting mitigation due to structural simplicity. The electromagnetic modeling of the SSR was made based on the RF parameter optimization. The simulation results show much narrower multipacting bandwidth, compared to those for the traditional spoke cavity. Mechanical analyses with stiffening structure at maximum allowable working pressures indicate acceptable stresses at the SSR cavity wall. In addition, the resonant frequency shifts due to fabrication and processing for cold tests are predicted and power coupling and tuning mechanism are also investigated.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-TUPO051  
About • paper received ※ 10 September 2018      issue date ※ 18 January 2019  
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TUPO054 Fundamental Studies of Impurity Doping in 1.3 GHz and Higher Frequency SRF Cavities cavity, niobium, SRF, radio-frequency 458
 
  • J.T. Maniscalco, P.N. Koufalis, M. Liepe
    Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
 
  As the demand for more powerful, more efficient, and smaller superconducting RF accelerators continues to increase, both impurity doping and high-frequency cavities (> 1.3 GHz) have become hot topics for fundamental research because of their potential to significantly decrease surface losses and cost respectively. In this report, we present recent experimental and theoretical results on undoped and nitrogen-doped high-frequency cavities and on alternative doping agents in traditional 1.3 GHz cavities, with a focus on understanding the fundamental science of impurity doping.  
slides icon Slides TUPO054 [1.956 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-TUPO054  
About • paper received ※ 16 September 2018      issue date ※ 18 January 2019  
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TUPO078 Extension of Busch’s Theorem to Particle Beams emittance, solenoid, experiment, cathode 516
 
  • L. Groening, C. Xiao
    GSI, Darmstadt, Germany
  • M. Chung
    UNIST, Ulsan, Republic of Korea
 
  In 1926, H. Busch formulated a theorem for one single charged particle moving along a region with longitudinal magnetic field. The theorem relates particle angular momentum to the amount of field lines being enclosed by the particle cyclotron motion. Recently it has been extended to accelerated particle beams [Phys. Rev. Accel. Beams 21 014201 (2018)]. This contribution sketches this extension and applies the extended theorem to successfully performed emittance manipulations with electron and ion beams.  
slides icon Slides TUPO078 [0.999 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-TUPO078  
About • paper received ※ 24 August 2018      issue date ※ 18 January 2019  
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TUPO090 Electron-beam Matching to Solenoid Magnetic Field in a Klystron klystron, gun, solenoid, cathode 534
 
  • S.J. Park, Y.J. Park
    PAL, Pohang, Kyungbuk, Republic of Korea
  • J.H. Hwang, S.-G. Shin
    POSTECH, Pohang, Kyungbuk, Republic of Korea
  • S.Y. Hyun, D.H. Yu
    Vitzrotech Co., Ltd., Ansan City, Kyunggi-Do, Republic of Korea
 
  Funding: The work was supported by the National R&D Program (grant number: 2016R1A6B2A01016828) through the National Research Foundation of Korea (NRF) funded by the Ministry of Science and ICT, Korea.
High-power klystrons for particle accelerators employ high-perveance electron guns which are usually focused by Solenoid magnets. The electron beam should be optically matched to the downstream magnetic field to prevent the beam from scalloping. The task usually requires a series of computer simulations with many design parameters, and therefore requires extensive(sometimes exhaustive) efforts if not aided by a priori experiences. In order to alleviate the difficulties we have developed a matching procedure which is systematic and reliable. In this article we describe the procedure with an example design of a 400-kV 500-A electron beam with radius 8 - 11 mm.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-TUPO090  
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TUPO092 Beam Dynamics and Collimation Following MAGIX at MESA* target, simulation, scattering, radiation 540
 
  • B. Ledroit, K. Aulenbacher
    IKP, Mainz, Germany
 
  Funding: * Supported by the DFG through GRK 2128
The Mainz Energy-recovering Superconducting Accelerator (MESA) will be an electron accelerator allowing operation in energy-recovery linac (ERL) mode, where beam energy is recovered by decelerating the beam in linac cryomodules and transferring kinetic energy to the RF. The ERL mode provides the opportunity to operate experiments at peak energy with thin targets, combining high luminosities typical for storage rings and high beam brightness typical for linacs. The MESA Internal Gas Target Experiment (MAGIX) aims to operate jet targets at high luminosities with different gases up to Xenon. As scattering effects in the beam rise with the atomic number, investigations on the impact of the target on beam dynamics and beam losses are required for machine safety. The goal of this work is to understand target induced halo, track halo particles through downstream sections and protect the machine with a suitable collimation system and shielding from direct and indirect damage through beam losses and radiation. The present status of the investigations is presented.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-TUPO092  
About • paper received ※ 11 September 2018      issue date ※ 18 January 2019  
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TUPO097 Design of C-band Electron Linear Accelerator for a Complex of Radiation Therapy gun, target, radiation, controls 550
 
  • L. Ovchinnikova, V.I. Shvedunov
    SINP MSU, Moscow, Russia
  • L. Ovchinnikova, V.I. Shvedunov
    LEA MSU, Moscow, Russia
 
  Funding: This material is based upon work supported by the Ministry of Education and Science of the Russian Federation, under Grant Agreement No. 14.582.21.0011, Grant Agreement Unique ID RFMEFI58217X0011.
The report presents the design of the linear electron accelerator for a complex of radiation therapy. The three-electrode electron gun and C-band accelerating structure are optimised to produce a therapeutic electron beam with an energy of 6 MeV and a dose rate of 10 Gy/min and a beam with an energy of 2.5 MeV to obtain a portal image. The beam size at the bremsstrahlung target in both modes does not exceed 2 mm. The total length of the accelerating system with the electron gun does not exceed 330 mm. The accelerating structure is fed by RF power from a multibeam klystron at a frequency of 5,712 MHz with a maximum pulsed power of 3.5 MW.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-TUPO097  
About • paper received ※ 10 September 2018      issue date ※ 18 January 2019  
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TUPO098 Proof-of-Principle Tests for Slit-scan-based Slice Emittance Measurements at PITZ emittance, FEL, laser, cathode 553
 
  • R. Niemczyk, P. Boonpornprasert, Y. Chen, J.D. Good, M. Groß, H. Huck, I.I. Isaev, D.K. Kalantaryan, C. Koschitzki, M. Krasilnikov, X. Li, O. Lishilin, G. Loisch, D. Melkumyan, A. Oppelt, H.J. Qian, Y. Renier, C. Saisa-ard, F. Stephan, Q.T. Zhao
    DESY Zeuthen, Zeuthen, Germany
  • W. Hillert
    University of Hamburg, Institut für Experimentalphysik, Hamburg, Germany
 
  Transverse slice emittance is one of the most important properties of high-brightness electron beams for freeelectron lasers (FELs). The photo injector test facility at DESY in Zeuthen (PITZ) develops high-brightness electron sources for modern FELs. With a 23 MeV, 1 nC beam at PITZ the experimental slice emittance characterization with the quadrupole scan technique is complicated by strong space charge effects. Combining the slit scan technique with a transverse deflecting cavity (TDS) allows for timeresolved emittance measurements of such a space-chargedominated beam. The first proof-of-principle results of slice emittance measurements at PITZ based on the ’TDS + slit scan’-technique are presented in this paper.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-TUPO098  
About • paper received ※ 04 September 2018      issue date ※ 18 January 2019  
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TUPO109 Electron Cloud Estimates for the Jefferson Lab EIC sextupole, proton, simulation, dipole 563
 
  • K.E. Deitrick, V.S. Morozov, T. Satogata
    JLab, Newport News, Virginia, USA
 
  Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177.
In this work, we present preliminary estimates for electron cloud build-up and saturation for the ion ring of the Jefferson Laboratory Electron-Ion Collider (JLEIC) currently under development. Using the baseline ion ring design, we study the impact of various operational parameters on the behavior of the electron cloud for a 100 GeV proton beam, including estimated tune shifts.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-TUPO109  
About • paper received ※ 12 September 2018      issue date ※ 18 January 2019  
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TUPO112 Calculation of Electron Beam Dynamics in Four Accelerating Stations for JINR Linear Electron Accelerator LINAC-200 linac, solenoid, acceleration, detector 566
 
  • A. Sledneva, V. Aleksandrov, V.V. Kobets
    JINR, Dubna, Moscow Region, Russia
 
  In the Joint Institute for Nuclear Research a Test Stand with an electron beam generated by the linear accelerator LINAC-200 with the energy up to 200 MeV is being constructed to investigate properties of accelerating and semiconducting structures for advanced detectors, a radiation resistance of detectors based on gallium arsenide semiconductor, to study a free electron laser and to do other applied for work. The technical characteristics of the LINAC-200 accelerator make it possible to create an advanced system of test beams for scientific and methodological studies of detectors on its basis. Four accelerating stations with maximum beam energy up to 200 MeV are put into operation. The work is being carried out for experiments with electron test beams with energy up to 800 MeV. This work presents the calculation results of the magnetic field of the focusing solenoidal system and electron beam dynamics in accelerating stations. In addition, the results on the formation of the electron beam with optimal parameters to be captured in further accelerating sections.  
poster icon Poster TUPO112 [1.176 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-TUPO112  
About • paper received ※ 12 September 2018      issue date ※ 18 January 2019  
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TUPO119 A Diagnostics Box for the Linear Accelerator of Institute for Research in Fundamental Science (IPM) linac, diagnostics, dipole, solenoid 581
 
  • S. Sanaye Hajari, M. Bahrami, H. Behnamian, S. Kasaei, H. Shaker
    IPM, Tehran, Iran
  • S. Ahmadiannamin
    ILSF, Tehran, Iran
  • F. Ghasemi
    NSTRI, Tehran, Iran
 
  The IPM linac is an 8 MeV (up gradable to 11 MeV) electron linear accelerator under development at Institute for Research in Fundamental Sciences, Tehran, Iran. The design and construction of the linac is nearly finished and it is in the commissioning stage. The commissioning is planned in several phase of different energy ranging from 50 keV to 8 MeV. At each phase appropriate diagnostics is required in order to investigate the linac performance. A diagnostics box including a scintillator view screen, a dipole magnet, and a focusing solenoid is designed to diagnose the beam longitudinal and transverse parameters in wide range of energy. These parameters are the beam transverse profile, size, position, emittance and the energy spectrum.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-TUPO119  
About • paper received ※ 12 September 2018      issue date ※ 18 January 2019  
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TUPO120 The Study of the Length and Shape of Beam in a High Power Electron Accelerator radiation, extraction, industrial-accelerators, simulation 584
 
  • M. Salehi, F. Abbasi Davani, B.G. Ghasemi
    Shahid Beheshti University, Tehran, Iran
  • F. Ghasemi, A.P. Poursaleh
    NSTRI, Tehran, Iran
 
  The output beam of a high-power linear accelerator, used for industrial purposes, is irradiated on products and scanning them. In order to improve the dosimetry of radiation which products received and to prevent loss of the attacked- beams to the edge of products, the exact evaluation of scanning length is necessary . One of the other challenges of the scanning beam is the lack of uniformity in dosimetry of received radiation . The scanning beam does not collide in parallel to the products, which is also a challenge to accelerator efficiency. To improve dosimetry of received radiation, the use of trajectory correction magnets is suggested. These magnets correct the beams that do not scan in parallel. Also, using the Monte Carlo code, the dosing rate of received radiation to products is simulated and compared in two non-uniform and uniform modes (corrected by trajectory correction magnets.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-TUPO120  
About • paper received ※ 12 September 2018      issue date ※ 18 January 2019  
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TUPO127 Activities at the Linac4 Test Stand emittance, rfq, linac, extraction 587
 
  • J.-B. Lallement, V. Bencini, S.B. Bertolo, F.D.L. Di Lorenzo, J. Lettry, A.M. Lombardi, C.M. Mastrostefano, D. Noll, M. O’Neil
    CERN, Geneva, Switzerland
 
  Linac4, the new CERN H injector to the Proton Synchrotron Booster, has been commissioned and has delivered a beam intensity and quality calculated to be sufficient to produce the standard beams for LHC and the high intensity beams for ISOLDE when connected. The beam current is nevertheless half of what is foreseen and the problem has been identified at the low energy end, between the extraction and the matching to the RFQ. The Linac4 test stand is being used to address this issue by testing different extraction geometries and different plasma generators. A fast method to access the current in the RFQ acceptance has been put in place. This paper reports the results of the measurements obtained so far.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-TUPO127  
About • paper received ※ 11 September 2018      issue date ※ 18 January 2019  
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WE1A03 Latest Results of CW 100 mA Electron RF Gun for Novosibirsk ERL Based FEL cavity, gun, cathode, radiation 598
 
  • V. Volkov, V.S. Arbuzov, E. Kenzhebulatov, E.I. Kolobanov, A.A. Kondakov, E.V. Kozyrev, S.A. Krutikhin, I.V. Kuptsov, G.Y. Kurkin, S.V. Motygin, A.A. Murasev, V.K. Ovchar, V.M. Petrov, A.M. Pilan, V.V. Repkov, M.A. Scheglov, I.K. Sedlyarov, S.S. Serednyakov, O.A. Shevchenko, S.V. Tararyshkin, A.G. Tribendis, N.A. Vinokurov
    BINP SB RAS, Novosibirsk, Russia
 
  Continuous wave (CW) 100 mA electron rf gun for injecting high-quality 300-400 keV electron beam to the Energy Recovery Linac (ERL) driving the Novosibirsk Free Electron Laser (FEL) was developed, built, and commissioned in a diagnostics beam line. The rf gun consists of normal conducting 90 MHz rf cavity with a gridded thermionic cathode unit. Tests of the rf gun confirmed its design performance in strict accordance with numerical simulations. The gun was tested up to the design specifications at a test bench that includes a diagnostics beam line. The design features of different components of the rf gun are presented. The commissioning experience is discussed. The latest beam results are reported.  
slides icon Slides WE1A03 [2.829 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-WE1A03  
About • paper received ※ 14 September 2018      issue date ※ 18 January 2019  
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WE1A05 SwissFEL Linac Commissioning Status, Current Performance and Future Plans FEL, linac, experiment, operation 605
 
  • P. Craievich
    PSI, Villigen PSI, Switzerland
 
  SwissFEL, the hard x-ray free-electron laser facility at PSI, is in an advanced commissioning phase. The commissioning of the 5.8 GeV Linac started in 2016 and the first FEL pilot-experiments were performed at a reduced beam energy in the end of 2017. In 2018, it is foreseen to progressively increase the electron beam energy and photon energy up to the maximum design values, interleaved by several FEL pilot experiments. This paper gives an overview of the commissioning progress including the achieved machine performance and first operational experience.  
slides icon Slides WE1A05 [10.370 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-WE1A05  
About • paper received ※ 18 September 2018      issue date ※ 18 January 2019  
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WE1A06 Pulse-to-pulse Beam Modulation for 4 Storage Rings with 64 Pulsed Magnets power-supply, controls, positron, linac 609
 
  • Y. Enomoto, K. Furukawa, T. Kamitani, F. Miyahara, T. Natsui, M. Satoh, K. Yokoyama, M. Yoshida
    KEK, Ibaraki, Japan
  • H.S. Saotome
    Kanto Information Service (KIS), Accelerator Group, Ibaraki, Japan
  • S. Ushimoto
    Mitsubishi Electric System & Service Co., Ltd, Tsukuba, Japan
 
  The KEK injector linac has delivered electrons and positrons for particle physics and photon science experiments for more than 30 years. It is planned to inject electron and positron beams with energies from 2.5 GeV to 7 GeV pulse-by-pulse at 50 Hz into the dual ring SuperKEKB collider and two light source storage rings. As the beam quality requirement from SuperKEKB is demanding, the beam orbit and optics conditions have to be maintained precisely. To that end 64 newly designed pulsed magnets were installed. Quadrupole magnets with the inductance of 1 mH are driven by power supplies with pulses up to 330 A and 0.5 ms, which recover the energy stored in coils up to 65%. Orbit corrector magnets with the inductance of 3 mH are driven with bipolar pulsed power supplies up to 10 A. Those power supplies are controlled under the event-based synchronized controls and monitored pulse-by-pulse, and are confirmed to have the stability over weeks within 0.1%. The details of the design and the operational performance will be reported.  
slides icon Slides WE1A06 [6.694 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-WE1A06  
About • paper received ※ 11 September 2018      issue date ※ 18 January 2019  
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TH1A01 First Ever Ionization Cooling Demonstration in MICE emittance, experiment, detector, scattering 632
 
  • J.Y. Tang
    IHEP, Beijing, People’s Republic of China
 
  Funding: STFC, DOE, NSF, INFN, CHIPP and more
The Muon Ionization Cooling Experiment (MICE) at RAL has studied the ionization cooling of muons. Several million individual particle tracks have been recorded passing through a series of focusing magnets in a number of different configurations and a liquid hydrogen or lithium hydride absorber. Measurement of the tracks upstream and downstream of the absorber has shown the expected effects of the 4D emittance reduction. This invited talk presents and discusses these results, and projects the future of ionization cooling.
Abstract submitted by the speakers bureau of the MICE Collaboration. If accepted, a member of the collaboration will be selected to present the contribution
 
slides icon Slides TH1A01 [6.524 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-TH1A01  
About • paper received ※ 19 September 2018      issue date ※ 18 January 2019  
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TH1A03 High Brightness Electron Beams from Plasma-based Acceleration plasma, acceleration, FEL, simulation 637
 
  • A. Marocchino, A. Biagioni, E. Brentegani, E. Chiadroni, M. Ferrario, F. Filippi, A. Giribono, R. Pompili, A.R. Rossi
    INFN/LNF, Frascati (Roma), Italy
  • A. Bacci
    Istituto Nazionale di Fisica Nucleare, Milano, Italy
  • A. Cianchi
    Università di Roma II Tor Vergata, Roma, Italy
  • V. Petrillo
    Universita’ degli Studi di Milano, Milano, Italy
 
  Funding: INFN-CNAF and CINECA for high performance computing resources. European Union Horizon 2020 programme N. 53782.
Plasma Wakefield acceleration is a promising new acceleration techniques that profit by a charged bunch, e.g. an electron bunch, to break the neutrality of a plasma channel to produce a wake where a trailing bunch is eventually accelerated. The quest to achieve extreme gradient conserving high brightness has prompted to a variety of new approaches and techniques. Most of the proposed schemes are however limited to the only plasma channel, assuming in the vast majority of cases, ideal scenarios (e.g. ideal bi-gaussian bunches and uniform density plasma channels). Realistic start-to-end simulations, from the photo-cathode to FEL via a high gradient, emittance and energy spread preserving plasma section, are mandatory for paving the way towards plasma-based user facilities.
 
slides icon Slides TH1A03 [25.814 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-TH1A03  
About • paper received ※ 11 September 2018      issue date ※ 18 January 2019  
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TH1A04 The Proton Driven Advanced Wake Field Acceleration Experiment (AWAKE) at CERN plasma, proton, wakefield, acceleration 642
 
  • S. Döbert
    CERN, Geneva, Switzerland
 
  The Advanced Proton Driven Plasma Wakefield Acceleration Experiment (AWAKE) aims at studying plasma wake field generation and electron acceleration driven by proton bunches. It is a proof-of-principle R&D experiment at CERN and the world’s first proton driven plasma wake field acceleration experiment. The experiment uses the 400 GeV proton beam from the SPS which travels through a 10 m long Rb-vapour plasma cell where it gets self-modulated and generates the plasma wake fields. Eventually an electron beam is injected externally to probe the wake-fields. AWAKE will has completed several experimental campaigns starting in 2016. Results from the initial characterization of the plasma cell and measurements of the seeded self-modulation of the proton beam will be presented. Experiments to accelerate externally injected electrons using the proton driven plasma wake fields will start in 2018 and first results will be reported.  
slides icon Slides TH1A04 [4.787 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-TH1A04  
About • paper received ※ 12 September 2018      issue date ※ 18 January 2019  
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THPO004 Pulsed Operation of CEBAF for JLEIC Injection cavity, injection, beam-loading, linac 682
 
  • J. Guo, J.M. Grames, R. Kazimi, F. Lin, T. E. Plawski, R.A. Rimmer, H. Wang
    JLab, Newport News, Virginia, USA
 
  Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177.
JLab Electron Ion Collider (JLEIC) is planning to use the recently upgraded 12 GeV CEBAF 1497 MHz SRF CW recirculating linac as a full-energy injector for the electron collider ring. The JLEIC electron injection requires 3-4µs long bunch trains with a 20-400ms spacing in between, resulting in uneven beam loading for the CW CEBAF. With the high beam current in JLEIC collider rings, the low duty factor of injection also requires to a very high pulsed beam current from CEBAF, exacerbating the transient beam loading issue. In this paper, we will present CEBAFs detailed pulsed operation scheme for JLEIC injection, as well as some experimental results at CEBAF.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO004  
About • paper received ※ 20 September 2018      issue date ※ 18 January 2019  
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THPO010 Novel Straight Merger for Energy Recovery Linacs cavity, dipole, experiment, linac 702
 
  • K.E. Deitrick, A. Hutton
    JLab, Newport News, Virginia, USA
  • A.C. Bartnik, C.M. Gulliford
    Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
  • S.A. Overstreet
    ODU, Norfolk, Virginia, USA
 
  Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177.
One of the most critical design considerations for an energy recovery linac (ERL) is how to merge the injected bunch onto the linac axis with minimal beam degradation. All merger designs in established and upcoming machines involve significant bending of the injected beam ’ even using a so-called straight merger bends the injected beam several degrees. We propose a merger which reduces the bending of the injected beam by an order of magnitude. By passing both beams through a septum magnet followed by an rf separator cavity with a superimposed dipole magnetic field, the injected beam bends minimally within the cavity, while the recirculated beam bends to align with the linac axis. Here we describe the concept in detail and present simulation results to demonstrate the advantages of such a design, particularly for magnetized beams or minimal energy separation between the injected and recirculated beams. Measurements from an experiment at CBETA evaluating the beam dynamics of the rf separator are presented and compared with simulation results.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO010  
About • paper received ※ 12 September 2018      issue date ※ 18 January 2019  
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THPO016 Investigation of 2D PBG Waveguides for THz Driven Acceleration GUI, acceleration, impedance, photon 714
 
  • A. Vint, R. Letizia
    Cockcroft Institute, Lancaster University, Lancaster, United Kingdom
  • R. Letizia
    Lancaster University, Lancaster, United Kingdom
 
  Funding: Work supported by the STFC PhD Studentship
Novel accelerating techniques that overcome the limitations of conventional RF technology are receiving significant interest. Moving from RF to the THz frequency range, higher gradient of acceleration of high energy beams can be achieved in miniaturised structures. Moreover, with respect to the optical frequency range, the THz regime allows for larger structures and better beam quality to be obtained. In this paper, we investigate the use of a 2D photonic bandgap (PBG) waveguide for THz driven electron acceleration. In accelerator applications, the properties of PBG waveguides can be exploited to damp higher order modes and offer low-loss dielectric confinement at high frequency. In particular, 2D PBG waveguides offer a good compromise between manufacturability, total photonic bandgap confinement, and ease of parallel illumination. The structure here proposed is optimised for maximum bandgap and single mode operation. Dispersion characteristics of the accelerating mode are studied to achieve the best compromise between high accelerating field and effective accelerating bandwidth, given a ~10% bandwidth of the THz driving pulse.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO016  
About • paper received ※ 12 September 2018      issue date ※ 18 January 2019  
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THPO017 Progress of the Novel Three-dimensional Spiral Injection Scheme Test Experiment kicker, injection, site, experiment 717
 
  • M.R. Rehman
    Sokendai, Ibaraki, Japan
  • K. Furukawa, H. Hisamatsu, T. Mibe, H. Nakayama, S. Ohsawa
    KEK, Ibaraki, Japan
  • H. Iinuma
    Ibaraki University, Hitachi, Ibaraki, Japan
 
  Funding: This work was supported by JSPS KAKENHI Grant Number JP26287055 and JP 23740216.
A new muon g-2/EDM experiment at J-PARC (E34) is under preparation in order to resolve a 3𝜎 discrepancy of muon anomalous magnetic dipole moment between the measurement and the standard model prediction. The E34 experiment will employ a unique three-dimensional spiral injection scheme in order to store the muon beam into a small storage orbit. In order to demonstrate the feasibility of this novel injection scheme, the Spiral Injection Test Experiment (SITE) with the electron beam is under construction at KEK Tsukuba campus. The goals of the SITE are divided into two phases. In the first phase of the SITE, 80 keV DC electron beam was injected and detected as a fluorescent light due to the de- excitation of the nitrogen gas into solenoidal storage magnet. In the second phase of the SITE, the pulsed electron beam, and a pulsed magnetic kicker are developed in order to keep the pulsed beam on the very midplane of the solenoidal storage magnet. This paper describes the achievements of the first phase of SITE and progress towards the second phase.
*H. Iinuma et al., Nuclear Instruments and Methos in Physics Research A, 832, 51-62 (2016).
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO017  
About • paper received ※ 12 September 2018      issue date ※ 18 January 2019  
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THPO020 Dynamic Behavior of Electron Beam under Rf Field and Static Magnetic Field in Cyclotron Auto-resonance Accelerator SRF, GUI, resonance, acceleration 725
 
  • Y.T. Yuan
    HUST, Wuhan, People’s Republic of China
  • K. Fan
    Huazhong University of Science and Technology, State Key Laboratory of Advanced Electromagnetic Engineering and Technology,, Hubei, People’s Republic of China
  • Y. Jiang
    Yale University, Beam Physics Laboratory, New Haven, Connecticut, USA
 
  Funding: the National Natural Science Foundation of China
The cyclotron auto-resonance accelerator (CARA) is a novel concept of accelerating continuous gyrating charged-particle beams to moderately or highly relativistic energies, which can be used as the high power microwave source and applied in environment improvement area, particularly in the flue gas pollution remediation. In CARA, the continuous-wave (CW) electron beam follows a gyrating trajectory while undergoing the interaction with the rotating TE-mode rf field and tapered static magnetic field. In the process of gyrating acceleration, the phase synchronization with the rf field is automatically maintained, so to speak, with auto-resonance. Simulation models are constructed to study the effect of rf field and static magnetic field on electron beam in CARA, where the beam energy, trajectory and velocity component are analysed. The simulation results match reasonably well with theoretical predication, which sets up a solid foundation for future designs of CARA.
 
poster icon Poster THPO020 [1.448 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO020  
About • paper received ※ 11 September 2018      issue date ※ 18 January 2019  
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THPO021 Research on X Ray Characteristics Produced by Highenergy Picosecond Electron Beam Shooting target, photon, linac, radiation 729
 
  • X.D. Zhang, X.P. Ouyang, B. Sun, X.J. Tan, X.F. Weng
    NINT, Xi’an, People’s Republic of China
 
  Funding: Supported by National Natural Science Foundation of China(11375142)
The X ray sources based on electron linac can produce X-rays with high energy, concentrated directions, and strong penetrating power, which have been widely applied in various fields. An electronic linear accelerator which has been built at present can provide an electron beam with energy of 120 MeV and pulse width of picosecond. The electron beam shooting at the metal targets can produce ultra-fast pulsed X-rays in the order of picosecond. In this paper, the pulse X ray characteristics are studied through simulating electron beam shooting at four metal targets with different thickness of Au, Ta, U, W and Pb by MCNPX program. The calculation shows that the X-rays can reach about 1010p/pulse and the pulse width can reach about picosecond level, when the pulsed electron beams with energy of 120 MeV ,charge of 0.5nC and pulse width of picosecond shooting at Ta targets. The yield and time width of pulsed X-rays are related to the diameter and thickness of the target.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO021  
About • paper received ※ 11 September 2018      issue date ※ 18 January 2019  
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THPO068 AN Effect of Field Emission on Low Beta Superconducting Cavities pick-up, cavity, SRF, linac 849
 
  • X. Liu, Z. Gao, Y. He, G. Huang
    IMP/CAS, Lanzhou, People’s Republic of China
 
  Superconducting RF (SRF) technology is widely ap-plied in particle accelerators to shorten the accelerator length and lower the construction price due to its high acceleration gradients with low rf losses. Field emission is the chief limitation associated with the surface electric field which will finally determine the cavity performance during the operation. The pickup-drop signal caused by field emission seriously affect the stable operation of the superconducting linac in the Chinese initiative Accelera-tor-Driven Sub-critical System (CiADS) demon facility. Simulations of the field emission effect and experimental measurements of the pickup-drop signal have been per-formed on the half wavelength resonator (HWR) cavity. And a modified design of the pickup antenna will be discussed to solve the pickup-drop problem.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO068  
About • paper received ※ 12 September 2018      issue date ※ 18 January 2019  
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THPO069 The Electromagnetic Optimization of TE-sample Host Cavity at IMP cavity, SRF, niobium, linac 852
 
  • S.C. Huang, Y. He, T. Tan, S.X. Zhang
    IMP/CAS, Lanzhou, People’s Republic of China
 
  As a part of the research and development work of thin-film materials for superconducting radio frequency(SRF) application in future accelerators at IMP, a 3.9GHz TE sample host cavity is being developed for the purpose of characterizing the RF Property and the loss mechanism of thin-film materials, which operates in the TE011 mode and accommodates disk sample with 110mm diameter, theoretically, the maximum magnetic field on sample surface will go up to 100mT, the resolution of surface resistance on sample will below nOhm by using thermometry technique( T-Mapping). In this paper, the electromagnetic optimization result of TE-sample host cavity will be presented, and the design consideration of hook tip style coupler and T-mapping system are also discussed.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO069  
About • paper received ※ 12 September 2018      issue date ※ 18 January 2019  
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THPO082 Physical Design of a Rectangular RF Deflector for Ultrashort Bunch Length Measurement cavity, FEL, simulation, coupling 872
 
  • J. Bai, Q.S. Chen, K. Fan
    HUST, Wuhan, People’s Republic of China
 
  Cylindrical deflectors which are now widely used for bunch length measurement suffer from the degeneration of polarization, while rectangular deflectors can separate polarization mode easily. This paper is focused on the study of a one-cell rectangular deflector, which is considerably different from cylindrical structure or multi-cell structure. A one-cell structure is free of π mode restriction and can achieve higher deflection efficiency per unit length. The proposed scheme is expected to achieve time resolution better than 200fs with the driving power less than 1MW. Cavity optimization and beam dynamic simulation are introduced in this paper.  
poster icon Poster THPO082 [0.484 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO082  
About • paper received ※ 11 September 2018      issue date ※ 18 January 2019  
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THPO084 BPM Time of Flight Measurements for Setting-up the RF Cavities of the CERN Linac4 linac, cavity, DTL, simulation 879
 
  • M. Bozzolan
    CERN, Geneva, Switzerland
 
  The newly constructed H LINAC4 at CERN has recently completed its first extended reliability run. It is equipped with Beam Position Monitors (BPMs) based on shorted-stripline pick-up electrodes to measure both position and Time of Flight (ToF). The ToF, in turn used to calculate the kinetic energy of the beam, is determined through signal phase shift measurements between pairs of BPMs. ToF measurements are performed by scanning of the phase of the RF injected into the cavities to find the nominal RF settings for optimal beam acceleration. This paper focuses on the technical aspects of the ToF measurement as well as on the results obtained during beam commissioning and their comparison with beam dynamics simulations.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO084  
About • paper received ※ 12 September 2018      issue date ※ 18 January 2019  
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THPO086 Beam Loss and Average Beam Current Measurements Using a CWCT proton, instrumentation, electronics, acceleration 882
 
  • F. Stulle, H. Bayle, J.F. Bergoz, T. Delaviere, L. Dupuy
    BERGOZ Instrumentation, Saint Genis Pouilly, France
  • P. Forck, M. Witthaus
    GSI, Darmstadt, Germany
  • D. Vandeplassche
    SCK•CEN, Mol, Belgium
  • J.X. Wu
    IMP/CAS, Lanzhou, People’s Republic of China
 
  The CWCT is a novel instrument adapted to an accurate average current determination of bunched CW beams or macro pulses. By combining a high-droop current transformer with novel electronics for signal analysis, an output signal bandwidth of DC to about 500kHz and a current resolution down to the micro-ampere level are achieved. Beam current fluctuations are followed within microseconds, permitting fast detection of beam loss. These characteristics render the CWCT an ideal instrument for HPPAs, for example ADS linacs, and other proton or ion accelerators. We present the CWCT principle and the CWCT performance achieved in beam experiments at UNILAC, GSI.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO086  
About • paper received ※ 11 September 2018      issue date ※ 18 January 2019  
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THPO097 Recent Results for Study of Ceramic and Copper Plating for Power Couplers survey, controls, target, FEL 905
 
  • Y. Yamamoto, E. Kako, S. Michizono
    KEK, Ibaraki, Japan
  • E. Cenni
    CEA/IRFU, Gif-sur-Yvette, France
  • A. Four
    CEA/DRF/IRFU, Gif-sur-Yvette, France
  • Y. Okii
    Nomura Plating Co, Ltd., Osaka, Japan
 
  KEK has conducted a survey to select an optimum ceramic after withdrawal by a domestic manufacturing company two years ago. For this selection, there are four important items on the properties of ceramic; that is, relative permittivity, dielectric loss tangent, surface and volume resistance, and secondary electron emission coefficient. For measurements of these parameters, five kinds of ceramic samples supplied from three companies were measured using three kinds of measurement systems. For measurement of secondary electron emission, scanning electron microscope (SEM) with beam blanking system was used. On the other hand, residual resistivity ratio (RRR) for copper plating, which is the most important item for quality control, has also been carried out while changing plating thickness and acid temperature. In this report, the recent results for these studies will be presented in detailed.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO097  
About • paper received ※ 12 September 2018      issue date ※ 18 January 2019  
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THPO100 Development of a 1.5 GHz High-power CW Magnetron for SRF Accelerator cavity, simulation, SRF, coupling 908
 
  • L. Wenliang
    College of Engineering and Applied Sciences for Nanjing University, Nanjing, People’s Republic of China
  • S. An, Y.J. Ke, S. Lingbin, Z. Pengjiao, L. Youchun, L. Zhao, B.Z. Zhou
    PLAI, Nanjing, People’s Republic of China
  • J.Z. Li, L.P. Zhang, Hou, R. Rui
    ADS, Jiangsu Province, People’s Republic of China
 
  An 1.5 GHz, 13.5 kW CW high-power magnetron for a superconducting RF accelerator has been developed by Andesun Technology Group Co., Ltd. with Nanjing Sanle Electronic Information Industry Group Co., Ltd., in order to replace the klystron, that could reduce the power source cost to about one-third. The cavity, output power antenna and coupling door-nob have been optimized by using CST Studio. Testing results have shown that the resonance frequency and output power have met the requirements, and the efficiency of the magnetron is higher that 78.45%.  
poster icon Poster THPO100 [0.574 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO100  
About • paper received ※ 12 September 2018      issue date ※ 18 January 2019  
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THPO102 Design Studies of Output Window for CEPC Klystron klystron, multipactoring, simulation, operation 911
 
  • Z.J. Lu, Y.L. Chi, S. Fukuda, G. Pei, S. Pei, S.C. Wang, O. Xiao, U. N. Zaib, Z.S. Zhou
    IHEP, Beijing, People’s Republic of China
  • S. Fukuda
    KEK, Ibaraki, Japan
 
  A high power and high efficiency klystron of the 650MHz, 800kW CW klystron for the Circular Electron Positron Collider (CEPC) is designed and developed at IHEP. This paper presents the design and simulation for the high power coaxial window for it. Plan of the hot test (high power testing before installing to the klystron) are also described. Simulation software of CST, ANSYS and Multipac 2.1 are used for design of window microwave structure, thermal analysis and multipacting effects. We obtained the good simulation results successively; the coaxial window S-parameter analysis, has revealed a low reflection at the operating frequency of 650 MHz. The thermal simulation shows a good temperature distribution under the cw 800kW propagation; maximum temperature has been found to be 33 °C at ceramic with water cooling in the inner and outer conductor. The multipacting at the window is possible source of the failure and it is shown that multipacting has less chance to be happened on the surface of ceramic.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO102  
About • paper received ※ 12 September 2018      issue date ※ 18 January 2019  
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THPO124 Design of Pulsed HV and RF Combined Gun System Using Gridded Thermionic-Cathode gun, emittance, cavity, cathode 949
 
  • T. Asaka, H. Tanaka
    RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan
  • Y. Otake
    JASRI, Hyogo, Japan
  • T. Taniuchi
    JASRI/SPring-8, Hyogo-ken, Japan
 
  In recent state-of -arts accelerators like an X-ray free electron laser, the electron beam performance of a linear accelerator demands a low emittance of ~ 2mm mrad. To obtain the low-emittance, such a 500kV thermionic-gun at SACLA and a photocathode rf gun generating 0.5~1MeV electron beams had been developed. Although the photocathode rf gun is compact, it is necessary to prepare a highly stabilized, large and complicated laser system. The 500-kV thermionic-gun of SACLA injector has also to prepare a technically difficult and large high voltage system. Hence, we propose a low-emittance gun system with a low-voltage and grid-loaded 50kV thermionic gun and a 238MHz rf cavity to overcome the complicated difficulty, as extension of the established technology. This system quickly accelerates the electron up to 500keV to preserve the low emittance and to cancel a grid focusing effect by the space charge force of the beam. By using a particle tracking code, we obtained the optimum voltage parameters of the grid and the 238MHz rf for obtaining the above-mentioned low emittance. In this paper, we present a numerical feasibility study to realize the low-emittance gun system.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO124  
About • paper received ※ 10 September 2018      issue date ※ 18 January 2019  
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THPO132 Study of the Electron Beam Transfer Line for the AWAKE RUN II Experiment at CERN plasma, experiment, proton, emittance 962
 
  • S.Y. Kim, M. Chung
    UNIST, Ulsan, Republic of Korea
  • M. Dayyani
    IPM, Tehran, Iran
  • S. Döbert
    CERN, Geneva, Switzerland
 
  Proton Beam-Driven Plasma Wakefield Accelerator (PBD-PWFA) has been actively investigated at CERN within the AWAKE experiments to study the electron beam acceleration using plasma wake fields of the order of GV/m. In the AWAKE RUN 1 experiment an electron beam with an energy of 19 MeV and a bunch length of 2.2 ps rms has been used for the first demonstration of electron beam acceleration in the plasma wake fields. It has been observed that the energy gain of the electron beam is up to 2 GeV, and electron capture efficiency is few percent. Higher capturing efficiency and emittance preservation could be achieved by making the electron beam short enough to be injected only into the acceleration and focusing phase of the plasma wake fields. The electron accelerator needs to be upgraded for AWAKE RUN 2 experiments to obtain a bunch length less than 100 fs which corresponds to a quarter of the plasma wavelength. Planned electron beam parameters for the AWAKE RUN 2 are a beam charge of 100 pC, and a beam energy larger than 50 MeV. In this paper, we show the electron beam parameters for RUN 2, and the parameters of the transfer line such as Twiss parameters, beam envelope, and emittance.
UNIST, Ulsan, 44919, Korea
Institute For Research in Fundamental Sciences, 19395-5531, Tehran, Iran
CERN, Geneva 1211, Switzerland
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO132  
About • paper received ※ 11 September 2018      issue date ※ 18 January 2019  
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FR1A02 Bunch Length Measurements using Transverse Deflecting Systems FEL, diagnostics, emittance, beam-diagnostic 972
 
  • M. Hüning
    DESY, Hamburg, Germany
 
  Shorter and shorter bunch lengths (some 10 fs) require sophisticated bunch length measurent devices. Free electron lasers - but not only - use transverse deflecting systems. Employing suitable diagnostic tools measurements are not limited to bunch lengths but can be extended to longitudinal profiles and phase-space distributions, and slice emittances. Not only do successfully operated systems aid the commissioning and operation of FELs but they allow control over more sophisticated phase-space manipulations. The design and construction of such systems, actually operated at different RF frequencies, includes cavity design and fabrication, powerful RF systems, low level RF control, beam lines, diagnostics, and data analysis.  
slides icon Slides FR1A02 [6.054 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-FR1A02  
About • paper received ※ 11 September 2018      issue date ※ 18 January 2019  
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FR1A06 Pulse-by-Pulse Beam Parameter Switching of High-Quality Beams for Multi-Beamline Operation at SACLA FEL, controls, laser, optics 988
 
  • H. Maesaka, T. Fukui, T. Hara, Y. Otake
    RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan
  • T. Hasegawa, O. Morimoto, Y. Tajiri, S. Tanaka, M. Yoshioka
    SES, Hyogo-pref., Japan
  • N. Hosoda, S. Matsubara, T. Ohshima
    JASRI/SPring-8, Hyogo-ken, Japan
  • C. Kondo, M. Yamaga
    JASRI, Hyogo, Japan
 
  The main linac of the X-ray free electron laser (XFEL), SACLA, provides electron beams to two XFEL beamlines and a beam transport line to the SPring-8 storage ring. In order to utilize these beamlines at the same time, a kicker magnet was installed into the switch yard and electron beams with a 60 Hz repetition rate can be distributed to these beamlines pulse-by-pulse. Since a beam energy and an optimum bunch length are usually different for each beamline, the operation condition of each acceleration unit, such as the rf phase, the trigger permission, etc., has to be changed pulse-by-pulse. Even in that case, the electron beam quality, such as 1 mm mrad normalized emittance, 10 fs bunch length, 10 kA peak current, etc., must not be deteriorated. At first, we developed a parameter control software that was able to manage two XFEL beamlines with an equal repetition rate. Different energy beams with sufficient quality for lasing were successfully distributed to the two XFEL beamlines and the XFEL performances of both beamlines were optimized simultaneously. The development status of a new parameter switching system with an arbitrary sequence of the destinations will also be reported.  
slides icon Slides FR1A06 [6.179 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-FR1A06  
About • paper received ※ 16 September 2018      issue date ※ 18 January 2019  
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