Keyword: experiment
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MOPO009 ELI-NP Gamma Beam System - Current Project Status laser, linac, gun, electron 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       paper accepted ※ 19 September 2018       issue date ※ 18 January 2019  
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MOPO019 Study on Cleaning of Copper Plated Bellows for LCLS-II cavity, SRF, FEL, cryomodule 71
 
  • L. Zhao, E. Daly, G.K. Davis, G.V. Eremeev, A.V. Reilly, A-M. Valente-Feliciano, K.M. Wilson
    JLab, Newport News, Virginia, USA
  
  Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contracts DE-AC05-06OR23177 and DE-AC02-76SF00515 for the LCLS-II Project.
Inter-cavity copper plated bellows are part of the LCLS-II cryomodule beamline components. Since the bellows are close to superconducting radio frequency (SRF) cavities during accelerator operation, it is desirable that these bellows have similar cleanliness as SRF cavi-ties. Studies have been done to help evaluate bellows interior cleanliness after the standard bellows cleaning procedure at Jefferson Lab. 		 
poster icon Poster MOPO019 [1.326 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-MOPO019  
About • paper received ※ 28 August 2018       paper accepted ※ 19 September 2018       issue date ※ 18 January 2019  
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MOPO020 Beam Dynamics Studies and Instrumentation Tests for Bunch Length Measurements at CLEAR gun, electron, 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       paper accepted ※ 20 September 2018       issue date ※ 18 January 2019  
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MOPO034 Dielectric Waveguide-Based THz Radiator Study for SwissFEL electron, 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       paper accepted ※ 21 September 2018       issue date ※ 18 January 2019  
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MOPO041 Performance Test Results of Magnet Power Supply controls, FPGA, interface, power-supply 118
 
  • K.-H. Park, J.H. Han, S.-H. Jeong, Y.G. Jung, D.E. Kim, M.J. Kim, H.-G. Lee, S.B. Lee, B.G. Oh, H.S. Suh
    PAL, Pohang, Kyungbuk, Republic of Korea
  
  A high stable magnet power supply (MPS) was developed, which was a bipolar type with 200A of the output current at the 40V of output voltage. The MPS has been implemented by the digital signal processing technology using the DSP, FPGA, ADCs and so on. The output current stability of the MPS showed about 6ppm peak-to-peak in a short term experiment at 200A of its full output current. The long term stability was shown in 15 ppm peak-to-peak for 10 hours at 200A. And the others experimental results about the MPS were shown in this paper.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-MOPO041  
About • paper received ※ 31 August 2018       paper accepted ※ 19 September 2018       issue date ※ 18 January 2019  
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MOPO085 Prototype of an Inter-digital H-mode Drift-tube Linac for Muon Linac cavity, linac, focusing, DTL 180
 
  • Y. Nakazawa, H. Iinuma
    Ibaraki University, Ibaraki, Japan
  • K. Hasegawa, Y. Kondo, T. Morishita
    JAEA/J-PARC, Tokai-mura, Japan
  • N. Hayashizaki
    RLNR, Tokyo, Japan
  • Y. Iwashita
    Kyoto ICR, Uji, Kyoto, Japan
  • Y. Iwata
    NIRS, Chiba-shi, Japan
  • N. Kawamura, T. Mibe, M. Otani, T. Yamazaki, M. Yoshida
    KEK, Ibaraki, Japan
  • R. Kitamura, H.Y. Yasuda
    University of Tokyo, Tokyo, Japan
  • N. Saito
    J-PARC, KEK & JAEA, Ibaraki-ken, Japan
  • Y. Sue
    Nagoya University, Graduate School of Science, Chikusa-ku, Nagoya, Japan
  
  An inter-digital H-mode (IH) drift-tube linac (DTL) is developed for a low velocity part in a muon linac at the J-PARC E34 experiment. It will accelerate muons from v/c = 0.08 to 0.28 at an operational frequency of 324 MHz. In order to achieve higher acceleration efficiency and make cost lower, an alternative phase focusing (APF) scheme is adopted. A prototype with 6 cells of 0.45 m length was manufactured. The prototype accelerates muons from v/c = 0.08 to 0.15 stage. We conducted frequency measurement and bead-pull measurement as a low-power measurement, in order to evaluate the prototype product. In this paper, the results of the low-power measurement for prototype cavity will be presented.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-MOPO085  
About • paper received ※ 10 September 2018       paper accepted ※ 19 September 2018       issue date ※ 18 January 2019  
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MOPO094 RF Stability Test of RFQ Cavity with Prototype Low-level Radio Frequency in RAON rfq, LLRF, cavity, controls 204
 
  • D.Y. Lee, B.H. Choi, C.O. Choi, H. Jang, H.C. Jung, K.T. Son
    IBS, Daejeon, Republic of Korea
  
  RAON is a heavy ion accelerator of the Institute for Basic Sciences (IBS) in Korea. The prototype Low-Level Radio Frequency (LLRF) operated at 81.25 MHz has been designed and fabricated for a prototype Radio Fre-quency Quadrupole (RFQ) cavity in RAON. Stabilities of ±1 % in amplitude and ±1 degree in phase are required for specifications of the RFQ system. The prototype LLRF controls the RF amplitude and phase in the cavity by PID feedback loop. The prototype LLRF has been tested with one RFQ cavity and stabilities have been measured. In this paper, we present the design and results of stability test.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-MOPO094  
About • paper received ※ 12 September 2018       paper accepted ※ 20 September 2018       issue date ※ 18 January 2019  
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MOPO095 A Risk Based Approach to Improving Beam Availability at an Accelerator Facility operation, GUI, factory, proton 207
 
  • W.C. Barkley, M.J. Borden, R.W. Garnett, M.S. Gulley, E.L. Kerstiens, M. Pieck, D. Rees, F.E. Shelley, B.G. Smith
    LANL, Los Alamos, New Mexico, USA
  
  Funding: United States Department of Energy
This paper describes a risk-based approach to improving beam availability at an accelerator facility. Los Alamos Neutron Science Center (LANSCE), like many other accelerator facilities, was built many years ago and has been re-purposed when new missions were adopted. Many of the upgrades to the accelerator and beamlines allowed improvements in the general area of the upgrade but large-scale, system-wide improvements were never accomplished. Because of this, the facility operates with a mix of old and new equipment of varying condition. Limited budgets have constrained spending for spares procurement making it vital to prioritize those items predicted to have the highest impact to availability, should they fail. A systematic approach is described where equipment is inventoried, condition assessed, rated for potential failure and finally compiled into a risk-based priority list. 		 
poster icon Poster MOPO095 [0.332 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-MOPO095  
About • paper received ※ 21 September 2018       paper accepted ※ 08 October 2018       issue date ※ 18 January 2019  
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MOPO120 Improvement of the Linear Part in the Tuner System of ADS 25 MeV Linac linac, proton, cavity, superconducting-cavity 250
 
  • L. Zhang, Z. Gao, L.B. Liu, F.F. Wang, B. Zhang
    IMP/CAS, Lanzhou, People’s Republic of China
  
  Tuner system is the indispensable part of ADS high current proton superconducting linac. It influences the working frequency of superconducting cavity of particle accelerator. To completely understand the working situa-tion of the tuner system and analyses the problems existing in it, experiments of linear part were fully conducted.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-MOPO120  
About • paper received ※ 09 September 2018       paper accepted ※ 21 September 2018       issue date ※ 18 January 2019  
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MOPO121 Large-Scale Optical Synchronization System of the European XFEL laser, FEL, timing, electron 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       paper accepted ※ 19 September 2018       issue date ※ 18 January 2019  
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MOPO129 Recent Results from the Study of Emittance Evolution at MICE emittance, detector, solenoid, lattice 270
 
  • W.B. Liu
    IHEP, Beijing, People’s Republic of China
  • V. Blackmore, C. Hunt
    Imperial College of Science and Technology, Department of Physics, London, United Kingdom
  
  Funding: STFC, DOE, NSF, INFN, CHIPP and more
The Muon Ionization Cooling Experiment (MICE) has measured the evolution of emittance due to ionization energy loss. Muons were focused onto an absorber using a large aperture solenoid. Lithium-hydride and liquid hy- drogen-absorbers have been studied. Diagnostic devices were placed upstream and downstream of the focus, ena- bling the phase-space coordinates of individual muons to be reconstructed. By observing the properties of ensem- bles of muons, the change in beam emittance was meas- ured. Data taken during 2016 and 2017 are currently un- der study to evaluate the change in emittance due to the absorber for muon beams with various initial emittance, momenta, and settings of the magnetic lattice. The current status and the most recent results of these analyses will be presented.
Submitted by the MICE speakers Bureau. If accepted a member of the collaboration will be selected for the mission 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-MOPO129  
About • paper received ※ 30 September 2018       paper accepted ※ 08 October 2018       issue date ※ 18 January 2019  
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MOPO130 Magnetic Flux Generated by Thermal Current in CEBAF 5-Cell Cavity System cavity, cryomodule, niobium, operation 273
 
  • R.L. Geng
    JLab, Newport News, Virginia, USA
  • S.C. Huang
    IMP/CAS, Lanzhou, People’s Republic of China
  
  The unloaded quality factor Q0 of many 5-cell CEBAF cavities were lowered by a factor of ~2 from their vertical qualification testing to their beam operation in CEBAF tunnel. Causes of this Q0 degradation were studied previously, including a more recent one addressing static fluxes arising from magnetic components near a 5-cell cavity. This paper reports on a preliminary study of the dynamic fluxes generated by a thermal current. Such a thermal current arises from the Seebeck effect and flows in closed loops formed by a niobium cavity and its surrounding tuner rods and liquid helium vessel that are made of stainless-steel. The behaviors of magnetic fluxes in response to various thermal profiles on a 5-cell CEBAF cavity with integrated tuner rods were studied in a JLAB VTA dewar. An outcome of this study is a proposed cool-down procedure for eliminating the thermal current generated magnetic fluxes around 5-cell cavities placed in CEBAF tunnels. This procedure may be useful to improve cavity Q0 in a cost-effective manner, which in turn saves cryogenic expenditures for sustaining CEBAF operation.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-MOPO130  
About • paper received ※ 01 September 2018       paper accepted ※ 19 September 2018       issue date ※ 18 January 2019  
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TUPO010 Muon Acceleration Test with the RFQ Towards the Development of the Muon Linac acceleration, rfq, simulation, diagnostics 342
 
  • R. Kitamura
    University of Tokyo, Tokyo, Japan
  • S. Bae, S. Choi, B. Kim
    SNU, Seoul, Republic of Korea
  • Y. Fukao, K. Futatsukawa, N. Kawamura, T. Mibe, Y. Miyake, T. Yamazaki
    KEK, Tsukuba, Japan
  • K. Hasegawa, Y. Kondo, T. Morishita
    JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
  • T. Iijima, Y. Sue
    Nagoya University, Graduate School of Science, Chikusa-ku, Nagoya, Japan
  • H. Iinuma, Y. Nakazawa
    Ibaraki University, Hitachi, Ibaraki, Japan
  • K. Ishida
    RIKEN Nishina Center, Wako, Japan
  • S. Li
    The University of Tokyo, Graduate School of Science, Tokyo, Japan
  • M. Otani, N. Saito
    J-PARC, KEK & JAEA, Ibaraki-ken, Japan
  • G.P. Razuvaev
    Budker INP & NSU, Novosibirsk, Russia
  
  The muon linac to accelerate muons 212 MeV is planned in order to measure the muon dipole moments precisely in the J-PARC. The muon acceleration with a RF accelerator hasn’t been demonstrated yet in the world. Therefore the muon acceleration test with the RFQ as the feasibility test of the muon linac was demonstrated at the Muon D line in the J-PARC MLF. Conventional muons are cooled with producing ultra-slow muons using the muonium production and the ionization laser for the muon linac. However these apparatuses couldn’t be used because of the limitation of the experimental area in the acceleration test. Therefore the conventional muon was converted to the negative muonium ion (Mu-) with less than 2 keV using the thin aluminum foil target as the easy cooling method. The Mu- was finally accelerated to 90 keV using the RFQ. The accelerated Mu- was selected with a diagnostic beam line and identified with the Time-Of-Flight measurement using a MCP detector. The result of the world’s first muon acceleration test with the RFQ will be reported in this presentation.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-TUPO010  
About • paper received ※ 12 September 2018       paper accepted ※ 21 September 2018       issue date ※ 18 January 2019  
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TUPO019 SPIRAL2 Cryogenic System Thermodynamic Behavior Prediction Through Dynamic Modeling cryomodule, cryogenics, cavity, controls 366
 
  • A.V. Vassal, P.-E. Bernaudin, A. Ghribi
    GANIL, Caen, France
  • P.-E. Bernaudin
    CEA/DSM/IRFU, France
  • P. Bonnay, F. Bonne
    CEA/INAC, Grenoble Cedex 9, France
  • F. Millet
    CEA, Grenoble, France
  
  SPIRAL 2 (Caen, France) is a state of the art superconducting linear accelerator composed of 26 quarter wave accelerating cavities. Each cavity is plunged in a liquid helium bath at 4.4 K itself surrounded by a thermal shield at 70 K. In this paper, a dynamic model of the cryogenic systemof the LINAC is proposed. Thismodel simulates the dynamic behaviour of the 19 cryomodules and their respective valves box connected through the cryodistribution. Model accuracy is evaluated through a comparison between simulation and experimental data. Using the model we should be able to predict the behaviour of the cryogenic system for different beam operating conditions of the accelerator. The model also highlights the link between the cryogenic system and the cavity RF losses through a dynamic estimator of those RF losses in the cavity walls. The latter could be used as a rough estimator of the quality factor of a cavity.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-TUPO019  
About • paper received ※ 13 September 2018       paper accepted ※ 20 September 2018       issue date ※ 18 January 2019  
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TUPO035 Determination of the Field-dependence of the Surface Resistance of Superconductors from Cavity Tests cavity, electromagnetic-fields, SRF, superconducting-cavity 405
 
  • J.R. Delayen, S.U. De Silva, H. Park
    ODU, Norfolk, Virginia, USA
  
  Cryogenic tests of superconducting cavities yield an average surface resistance as a function of the peak surface magnetic field. An analytical formalism has been developed to extract the actual field dependence of the surface resistance from cavity tests and is applied to coaxial cavities and cavities of more complex geometries.  
slides icon Slides TUPO035 [0.524 MB]  
poster icon Poster TUPO035 [1.002 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-TUPO035  
About • paper received ※ 12 September 2018       paper accepted ※ 19 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, electron, 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       paper accepted ※ 08 October 2018       issue date ※ 18 January 2019  
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TUPO038 Several Experimental Phenomena of Sn Nucleation on Nb Surface Observed at IMP cavity, SRF, HOM, niobium 412
 
  • Z.Q. Yang, Y. He, F. Pan
    IMP/CAS, Lanzhou, People’s Republic of China
  
  Nucleation process is an important step that affects the quality of Nb3Sn films coated by vapor diffusion method. A uniform distribution of nucleation centers is essential to the uniformity of Nb3Sn films. In this paper we report several experimental phenomena on the Sn nucleation on Nb surface. Better nucleation in the downstream of the pumping direction was observed. Influence of SnCl2 partial pressure inhomogeneity was studied. Samples with higher SnCl2 partial pressure have denser nucleation, which means homogeneous SnCl2 pressure is a critical factor to the uniform nucleation. Less-nuclear zones, mainly distributed at cracks, grain boundaries and even some whole grain surfaces, were found on the surfaces of all samples. The less-nuclear zones may result in the low tin regions of the Nb3Sn cavities. The specific solution to the less-nuclear problem was proposed. These studies help to better understanding of the mechanism underlying the nucleation process and will be useful foundation for the follow-up Nb3Sn/Nb project at IMP.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-TUPO038  
About • paper received ※ 12 September 2018       paper accepted ※ 19 September 2018       issue date ※ 18 January 2019  
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TUPO048 Study Progress of Pulse Laser Annealing for Niobium Film on Copper laser, ECR, niobium, cavity 438
 
  • Y. Yang, B.T. Li, X.Y. Lu, W.W. Tan, L. Xiao, D. Xie, D.Y. Yang
    PKU, Beijing, People’s Republic of China
  
  Funding: Work supported by Major Research Plan of National Natural Science Foundation of China (No. 91026001).
The recent studies of laser annealing on niobium films on copper are reported. Annealing is normally used to deal with the surface, reducing defects and even chang-ing the microstructure of the coating film. Short pulse laser can produce a sharp step temperature field on the film thickness scale (μm), which anneals the surface without substrate heated. The laser annealing experi-ments of niobium thin film sample have been carried out, and according to SEM and FIB results, Nb films melted and recrystallization occurred. Grains growing up can be observed while the power density of laser pulse in-creased. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-TUPO048  
About • paper received ※ 12 September 2018       paper accepted ※ 21 September 2018       issue date ※ 18 January 2019  
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TUPO050 Construction of Thin-film Coating System Toward the Realization of Superconducting Multilayered Structure cathode, cavity, SRF, site 445
 
  • R. Ito, T. Nagata
    ULVAC, Inc, Chiba, Japan
  • H. Hayano, T. Kubo, T. Saeki
    KEK, Ibaraki, Japan
  • H. Ito
    Sokendai, Ibaraki, Japan
  • Y. Iwashita, R. Katayama
    Kyoto ICR, Uji, Kyoto, Japan
  • H. Oikawa
    Utsunomiya University, Utsunomiya, Japan
  
  Although S-I-S (superconductor-insulator-superconductor) multilayered structure is expected to increase the maximum acceleration gradient of SRF cavities, in order for it to function in reality, it is necessary to develop a coating processing that can realize high purity and quality superconducting thin-films. We launched the co-sputtering system to create superconducting alloy thin-films such as Nb3Sn and to research how the characteristics of them change depending on the coating conditions. The deposition rate of two elements was optimized by adjusting each input power, so we successfully obtained an alloy thin-film having appropriate composition ratio. In addition, we developed another experimental equipment for coating on the inner surface of the 3GHz TESLA type small cavities. A cylindrical shape Nb in which some permanent magnets are inserted was adopted as the sputtering target. Glow discharge of the target was confirmed, and the inner-sputtering test was conducted. This presentation reports the specifications of the two sputtering apparatuses and the results of the coating test.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-TUPO050  
About • paper received ※ 18 September 2018       paper accepted ※ 08 October 2018       issue date ※ 18 January 2019  
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TUPO066 Lower Critical Field Measurement of Thin Film Superconductor solenoid, controls, SRF, MMI 484
 
  • H. Ito
    Sokendai, Ibaraki, Japan
  • C.Z. Antoine
    CEA/IRFU, Gif-sur-Yvette, France
  • A. Four
    CEA/DRF/IRFU, Gif-sur-Yvette, France
  • H. Hayano, T. Kubo, T. Saeki
    KEK, Ibaraki, Japan
  • R. Ito, T. Nagata
    ULVAC, Inc, Chiba, Japan
  • Y. Iwashita, R. Katayama, H. Tongu
    Kyoto ICR, Uji, Kyoto, Japan
  • H. Oikawa
    Utsunomiya University, Utsunomiya, Japan
  
  Funding: The work is supported by Japan Society for the Promotion of Science Grant-in-Aid for Young Scientist (A) No.17H04839.
Superconducting thin film is the promising technology to increase the performance of SRF cavities. The lower critical field Hc1, which is one of the important physical parameters characterizing a superconducting material, will be enhanced by coating Nb with thin film superconductor such as NbN. To investigate the Hc1, we developed the Hc1 measurement system using the third harmonic response of applied AC magnetic field. The measurement system consists of helium cryostat with two of GM refrigerators, sample Cu stage, solenoid coil Cu mount, solenoid coil, temperature sensors, and liquid helium level meter. AC magnetic field is produced by a coil which is driven by function generator and power amplifier at around 1 kHz. In order to control the temperature of the sample, we installed heaters and thermal anchors which could be moved by the motor. By this temperature control the sample state can be easily transferred from Meissner state to mixed state. So that the measurement is repeated for various applied magnetic field, and the transition curve can be made. In this report, measurement result of the bulk Nb sample and NbN-SiO2 multilayer thin film sample will be discussed. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-TUPO066  
About • paper received ※ 19 September 2018       paper accepted ※ 20 September 2018       issue date ※ 18 January 2019  
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TUPO067 Study on New Removal Thickness Distribution Improvement Methods for Niobium 9-cell Cavity Vertical Electropolishing with Ninja Cathode cathode, cavity, niobium, status 488
 
  • K.N. Nii, V. Chouhan, Y.I. Ida, T.Y. Yamaguchi
    MGH, Hyogo-ken, Japan
  • H. Hayano, S. Kato, H. Monjushiro, T. Saeki, M. Sawabe
    KEK, Ibaraki, Japan
  
  Marui Galvanizing Co., Ltd. has been developing niobium 9-cell cavity vertical electropolishing (VEP) technologies with Ninja cathode in collaboration with KEK. Conventional 9-cell cavity VEP had a serious problem, which was asymmetry of removal thickness distribution. Usually removal thickness of upper side became larger than lower side in case of both in-cell and inter-cell. So far, as one solution, we proposed bubble diffusion prevention method and proved it was effective for uniform removal. This time, as other new solution, we tried cavity flip upside down and Ninja cathode masking VEP methods. In this article we will report the purpose, intention and VEP experiment result of these methods.  
poster icon Poster TUPO067 [0.858 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-TUPO067  
About • paper received ※ 13 September 2018       paper accepted ※ 21 September 2018       issue date ※ 18 January 2019  
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TUPO078 Extension of Busch’s Theorem to Particle Beams emittance, solenoid, cathode, electron 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       paper accepted ※ 19 September 2018       issue date ※ 18 January 2019  
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TUPO084 Beam Dynamics Simulations for the New Superconducting CW Heavy Ion LINAC at GSI linac, cavity, heavy-ion, cryomodule 525
 
  • M. Schwarz, M. Basten, M. Busch, H. Podlech
    IAP, Frankfurt am Main, Germany
  • K. Aulenbacher
    IKP, Mainz, Germany
  • K. Aulenbacher, W.A. Barth, F.D. Dziuba, V. Gettmann, T. Kürzeder, M. Miski-Oglu
    HIM, Mainz, Germany
  • W.A. Barth, M. Heilmann, A. Rubin, A. Schnase, S. Yaramyshev
    GSI, Darmstadt, Germany
  
  Funding: Work supported by BMBF contr. No. 05P15RFRBA, EU Framework Programme H2020 662186 (MYRTE) and HIC for FAIR
For future experiments with heavy ions near the coulomb barrier within the super-heavy element (SHE) research project a multi-stage R&D program of GSI/HIM and IAP is currently in progress. It aims for developing a supercon-ducting (sc) continuous wave (CW) LINAC with multiple CH cavities as key components downstream the High Charge State Injector (HLI) at GSI. The LINAC design is challenging due to the requirement of intense beams in CW mode up to a mass-to-charge ratio of 6, while covering a broad output energy range from 3.5 to 7.3 MeV/u with unchanged minimum energy spread. Testing of the first CH-cavity in 2016 demonstrated a promising maximum accelerating gradient of Ea = 9.6 MV/m; the worldwide first beam test with this sc multi-gap CH-cavity in 2017 was a milestone in the R&D work of GSI/HIM and IAP. In the light of experience gained in this research so far, the beam dynamics layout for the entire LINAC has recently been updated and optimized. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-TUPO084  
About • paper received ※ 12 September 2018       paper accepted ※ 20 September 2018       issue date ※ 18 January 2019  
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TUPO095 Beam Loading with the First Rebuncher of Spiral2, First Measurements cavity, simulation, controls, linac 546
 
  • M. Lechartier, R. Ferdinand, J.F. Leyge
    GANIL, Caen, France
  
  In the SPI2 project the middle energy line (LME) is equiped with a radio frequency qupole and three Rebunchers. The subject of this article is to measure and characterise the effect of the beam loading on the first Rebuncher cavity.  
poster icon Poster TUPO095 [1.146 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-TUPO095  
About • paper received ※ 20 September 2018       paper accepted ※ 15 January 2019       issue date ※ 18 January 2019  
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WE1A05 SwissFEL Linac Commissioning Status, Current Performance and Future Plans linac, FEL, electron, 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       paper accepted ※ 09 October 2018       issue date ※ 18 January 2019  
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TH1A01 First Ever Ionization Cooling Demonstration in MICE emittance, detector, scattering, electron 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       paper accepted ※ 31 October 2018       issue date ※ 18 January 2019  
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TH1A05 Jitter Study for the APS Linac Photo-injector Beam laser, timing, linac, simulation 647
 
  • D. Hui, M. Borland, J.M. Byrd, Y. Sun
    ANL, Argonne, Illinois, USA
  
  Funding: *Work supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357.
The APS Linac photo-injector can deliver high brightness electron beams to the Linac Extension Area (LEA) for beam experiments such as TESSA (Tapering Enhanced Stimulated Superradiant Amplification). Beam jitter in the device-under-test (DUT) area of the LEA can adversely affect the quality of data for such experiments. In this paper, a start-to-end simulation of jitter is studied. Sources of jitter include photo-cathode drive-laser arrival time, laser energy, and RF phases and voltages of the photo-cathode gun and accelerating cavities. It is found that at the DUT the relative mean energy jitter is the most significant concern, and that improvements in the Linac RF voltage stability can help to reduce it. RMS energy spread are more sensitive to the laser timing and charge jitter. The laser timing jitter itself can be compressed by the magnetic chicane by a factor of 5.6. 		 
slides icon Slides TH1A05 [4.377 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-TH1A05  
About • paper received ※ 10 September 2018       paper accepted ※ 20 September 2018       issue date ※ 18 January 2019  
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THPO007 MESA - Status of the Implementation of the MicroTCA.4-based LLRF Control System cavity, controls, LLRF, simulation 691
 
  • J.N. Bai, K. Aulenbacher, J. Diefenbach, F. Fichtner
    IKP, Mainz, Germany
  • P. Echevarria
    HZB, Berlin, Germany
  • R.G. Heine
    KPH, Mainz, Germany
  
  MESA at the Institut für Kernphysik (KPH) at Johannes Gutenberg-Universität Mainz is a multi-turn energy recovery linac (ERL), aiming to serve as user facility for particle physics experiments. The RF-accelerating systems of MESA consist of four 9-cell TESLA superconducting cavities, four normal conducting (NC) pre-accelerator cavities, two NC buncher cavities and two NC chopper cavities. They operate in continuous wave (CW) mode. In order to control the radio frequency (RF) amplitude and phase within the 12 cavities with the required accuracy and stability in the range of better than 0.01% and 0.01°, the MicroTCA.4 based digital low-level RF (LLRF) control system based on the development at DESY, Hamburg will be well adapted for the MESA cavities. In this paper, we describe the theoretical modelling of superconducting cavity and PID controller in SIMULINK which is useful to find the suitable control parameter for the PID controller and to predict the system performance. The progress to date of the implementation and tests of the LLRF system at MESA will also be presented.  
poster icon Poster THPO007 [1.274 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO007  
About • paper received ※ 11 September 2018       paper accepted ※ 09 October 2018       issue date ※ 18 January 2019  
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THPO010 Novel Straight Merger for Energy Recovery Linacs cavity, dipole, simulation, electron 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       paper accepted ※ 20 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, electron 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       paper accepted ※ 21 September 2018       issue date ※ 18 January 2019  
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THPO034 Experimental Study of Tuning Method on a Model Alvarez DTL Cavity for CPHS Project cavity, DTL, linac, drift-tube-linac 756
 
  • Y. Lei, X. Guan, R. Tang, X.W. Wang, Q.Z. Xing, S.X. Zheng
    TUB, Beijing, People’s Republic of China
  
  This article is devoted to the experimental study of tun-ing method for an Alvarez-type drift tube linac (DTL) of the Compact Pulse Hadron Source (CPHS) project at Tsinghua University. The biperiodic structure based on the post couplers are introduced to overcome the instability of the Alvarez DTL tank which is used to operate in 0 (or 2π) mode. The experimental method and results are pre-sented, and the tuning scheme for the formal CPHS DTL is summarized from the tuning experiment.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO034  
About • paper received ※ 12 September 2018       paper accepted ※ 20 September 2018       issue date ※ 18 January 2019  
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THPO048 Low Power Measurement of a 1300-MHz RFQ Cold Model rfq, linac, emittance, acceleration 794
 
  • Y. Kondo, T. Morishita, J. Tamura
    JAEA/J-PARC, Tokai-mura, Japan
  • M. Otani
    KEK, Ibaraki, Japan
  
  Funding: This work is supported by JSPS KAKENHI Grant Number 17K18784.
A muon linac development for a new muon g-2/EDM experiment is now going on at J-PARC. Muons from the muon beam line (H-line) of the J-PARC muon facility are once stopped in a silica aerojel target and room temperature muoniums are evaporated from the aerogel. They are dissociated with the lasers to be the ultra slow muons, then accelerated up to 212 MeV using a linear accelerator. The low energy part of this muon linac consists of a 324-MHz RFQ and an IH DTL. The frequency is increased to 1296 MHz at the following CCL section. We propose to replace the low energy section to a 1300-MHz RFQ to simplify the configuration of the muon linac. The 1300-MHz RFQ will be extremely small compared to conventional RFQs, therefore we made a cold model to proof the feasibility of this scheme. In this paper, the result of low-power measurement of the 1300-MHz RFQ cold model is described. 		 
slides icon Slides THPO048 [2.160 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO048  
About • paper received ※ 12 September 2018       paper accepted ※ 20 September 2018       issue date ※ 18 January 2019  
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THPO080 Design Validation of a Chopping and Deflecting System for the High Current Injector at IUAC vacuum, diagnostics, simulation, power-supply 869
 
  • S. Kedia, R. Ahuja, R. Kumar, R. Mehta
    IUAC, New Delhi, India
  
  A chopping and deflecting system has been designed and developed to provide the chopped beam with various repetition rates at the IUAC experimental facilities. It consists of four pairs of deflecting plates with increasing gap from 15 mm to 21 mm to maximize the effective electric field, preserve the beam emittance and to maximize the transmission efficiency within the same voltage conditions. The design of CDS has been validated with various simulation codes like CST MWS, Solid Works, Python and TRACE 3D. The deflecting plates have been fabricated, and assembled with in the design accuracy of 100 microns. A vacuum chamber has been designed and fabricated to incorporate the deflector plate assembly. The CDS unit has been installed in the Low Energy Ion Beam Facility at the IUAC to validate the design value of ion beam deflection. A slit has been installed to cut the deflected charge particles. Since the pulse power electronics required for chopping is presently under design we have used DC voltage across the four pairs of deflecting plates and amount of deflection was measured accordingly. The design, development, and DC beam test will be discussed in the article.  
poster icon Poster THPO080 [2.037 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO080  
About • paper received ※ 12 September 2018       paper accepted ※ 20 September 2018       issue date ※ 18 January 2019  
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THPO090 The Analysis of Module Failure in High Solid-state Amplifier for High Current RFQ scattering, simulation, rfq, cavity 886
 
  • L.P. Sun, Y. He, G. Huang, C.X. Li, L. Lu, A. Shi, L.B. Shi, X.B. Xu, H.W. Zhao
    IMP/CAS, Lanzhou, People’s Republic of China
  
  New accelerator RF system was upgraded to the solid-state amplifier in ADS project due to its stable, sustainable and reliable. Until now, newest 80kW SSA was adopted in IMP, operating in 162.5MHz, and over 120 power modules were combined through several synthesizers for 80kW output. but since too many modules were optimized for amplitude and phase in the same time, one or some failure of circulator will lead to injure of whole RF system, when wavelength meets a specific condition, injure would turn out severe accident and heavy loss. In this paper, analyzing and simulating the multi-level synthetic matrix was the important method for ADS accident happened in June 20. 2017, the failure simulated results for RF amplify links under the specific circumstances also was presented simultaneously.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO090  
About • paper received ※ 17 September 2018       paper accepted ※ 31 October 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 electron, plasma, simulation, 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       paper accepted ※ 20 September 2018       issue date ※ 18 January 2019  
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FR1A01 Results From the 6D Diagnostics Test Bench at SNS simulation, quadrupole, diagnostics, emittance 966
 
  • B.L. Cathey
    ORNL RAD, Oak Ridge, Tennessee, USA
  • A.V. Aleksandrov, S.M. Cousineau, A.P. Zhukov
    ORNL, Oak Ridge, Tennessee, USA
  
  Funding: SNS is managed by UT-Battelle, LLC, under contract DE-AC05-00OR22725 for the U.S. Department of Energy. This work has been partially supported by NSF Accelerator Science grant 1535312.
This paper presents the method and results for measuring the full six-dimensional phase space of a low energy, high intensity hadron beam. This was done by combining four-dimensional emittance measurement techniques along with dispersion measurement and a beam shape monitor to provide the energy and arrival time components. The measurements were performed on the new Beam Test Facility (BTF) at the Spallation Neutron Source (SNS), a 2.5 MeV functional duplicate of the SNS accelerator front end. The results include a correlation the had not previously been observed. 		 
slides icon Slides FR1A01 [7.083 MB]  
poster icon Poster FR1A01 [1.742 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-FR1A01  
About • paper received ※ 11 September 2018       paper accepted ※ 20 September 2018       issue date ※ 18 January 2019  
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