Author: Irie, Y.
Paper Title Page
MOPME022 Beam Commissioning of Two Horizontal Pulse Steering Magnets for Changing Injection Painting Area from MLF to MR in the 3-GeV RCS of J-PARC 518
 
  • P.K. Saha, H. Harada, N. Hayashi, H. Hotchi, M. Kinsho, T. Takayanagi, N. Tani
    JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
  • Y. Irie
    KEK, Ibaraki, Japan
  • S. Kato
    Tohoku University, Graduate School of Science, Sendai, Japan
 
  We have been successfully commissioned two pulse steering magnets installed in the Linac to 3-GeV RCS (Rapid Cycling Synchrotron) injection beam transport (BT) line of J-PARC. RCS has to deliver a simultaneous as well as specific beam as demand by the downstream facilities of MLF (Material and Life Science Facility) and the MR (Main Ring). In order to obtain relatively a smaller transverse emittance at extraction, those magnets were designed to perform a smaller injection painting for the MR beam as compared to the MLF one. As stripper foil position is fixed for the charge exchange H injection, inclination of the injected beam centroid on foil for the MR beam is only moved to a smaller value by the pulse steering magnets, while DC septum magnets are fixed as determined first for the MLF beam. Their parameters were found to be very consistent with expectation and thus already in operation for switching to a painting area of 100 pi mm mrad for the MR beam as compared to that of 150 pi mm mrad for the MLF beam.  
 
MOPWA008 Power Supply of the Pulse Steering Magnet for Changing the Painting Area between the MLF and the MR at J-PARC 3 GeV RCS 681
 
  • T. Takayanagi, N. Hayashi, K. Horino, M. Kinsho, T. Togashi, T. Ueno, Y. Watanabe
    JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
  • Y. Irie
    KEK, Ibaraki, Japan
 
  The power supply of the pulse steering magnet (PSTR) has been produced. The PSTR of the 3-GeV RCS (Rapid Cycling Synchrotron) in the J-PARC (Japan Proton Accelerator Research Complex) aims at changing the painting area in a pulse-to-pulse mode at 25Hz between the MLF (Material and Life science Experimental Facility) and the MR (50-GeV Main Ring synchrotron) at J-PARC. The power supply has the equipment used to excite the pulse current and the direct current (DC) to correspond to two modes that the paint injection for beam users and the central injection for beam commissioning. In case of the paint injection, the power supply excites the current from 40 A to 450 A in pulse mode, which has the capability to switch from positive to negative polarity. The pulse current has been performed with good accuracy whose deviation to a setting current becomes to be less than ± 0.2 %. In case of the central injection, the power supply excites the current from 1000 A to 3000A in DC mode, which has been realized output current deviation below ± 0.01 %. This paper summarizes the design parameters and the experimental results of the power supply.  
 
TUPWA010 A Trial to Reduce the Kicker Impedance of 3-GeV RCS in J-PARC 1742
 
  • Y. Shobuda, N. Hayashi, T. Takayanagi
    JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
  • Y. Irie
    KEK, Ibaraki, Japan
  • T. Toyama
    J-PARC, KEK & JAEA, Ibaraki-ken, Japan
 
  At 3GeV RCS in J-PARC, the kicker impedance has been considered to be the dominant source to cause the beam instability. Recently, experimental studies demonstrate that the beam instability is suppressed by reducing the kicker impedance. In this report, a trial to reduce the kicker impedance is reported.  
 
WEPFI062 Precise Cavity Tuning System of a Low Output-impedance Second-harmonic Cavity at ISIS 2836
 
  • Y. Irie, S. Fukumoto, K. Muto, H. Nakanishi
    KEK, Ibaraki, Japan
  • D.B. Allen, D. Bayley, N.E. Farthing, I.S.K. Gardner, R.J. Mathieson, A. Seville, J.W.G. Thomason
    STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
  • J.C. Dooling, D. Horan, R. Kustom, M.E. Middendorf
    ANL, Argonne, USA
 
  A very low output-impedance (~35ohms) second-harmonic cavity system is being developed for high intensity proton accelerators. The final amplifier is comprised of a grounded cathode scheme with a feedback loop from anode to grid. Due to the Miller effect, the grid voltage waveform is seriously distorted even if only a few percent of sub-harmonic or higher harmonic are mixed in the generator current. Such distortion is much enhanced by the beam loading. In order to eliminate the effect of this distortion upon the phase detector used to achieve precise cavity tuning, a swept bandpass filter was applied to the grid voltage at the phase detector input. Filter design details and the result of high power tests are reported.  
 
THPWO032 Progress of Injection Energy Upgrade Project for J-PARC RCS 3833
 
  • N. Hayashi, H. Harada, K. Horino, H. Hotchi, J. Kamiya, M. Kinsho, P.K. Saha, Y. Shobuda, T. Takayanagi, N. Tani, T. Togashi, T. Ueno, M. Watanabe, Y. Watanabe, K. Yamamoto, M. Yamamoto, Y. Yamazaki, M. Yoshimoto
    JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
  • Y. Irie
    KEK, Ibaraki, Japan
  • T. Toyama
    J-PARC, KEK & JAEA, Ibaraki-ken, Japan
 
  The injection energy of the J-PARC RCS will be upgraded in 2013. New power supplies for the shift bump magnet system will be installed. Some of other systems, upgrade of the painting bump power supplies and pulse steering systems, are already installed and tested or used for the nominal operation. The paper reports the progress of injection energy upgrade project.  
 
THPWO033 High Intensity Beam Trial of up to 540 kW in J-PARC RCS 3836
 
  • H. Hotchi, H. Harada, N. Hayashi, M. Kinsho, P.K. Saha, Y. Shobuda, F. Tamura, K. Yamamoto, M. Yamamoto, M. Yoshimoto
    JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
  • Y. Irie
    KEK, Ibaraki, Japan
  • S. Kato
    Tohoku University, Graduate School of Science, Sendai, Japan
 
  Recently we have performed a high intensity beam trial of up to 540 kW. In this paper, beam intensity dependece and injection painting parameter dependence of beam loss, observed in this beam experiment, will be discussed with the corresponding numerical simulation results.