Author: Shirakata, M.J.
Paper Title Page
TUPC098 Beam Profile Measurement using Flying Wire Monitors at the J-PARC Main Ring* 1239
 
  • S. Igarashi, K. Ohmi, Y. Sato, M.J. Shirakata, M. Tejima, T. Toyama
    KEK, Ibaraki, Japan
  • Y. Hashimoto, K. Satou
    J-PARC, KEK & JAEA, Ibaraki-ken, Japan
 
  Transverse beam profiles have been measured using flying wire monitors at the main ring of the Japan Proton Accelerator Research Complex (J-PARC). The flying wire is a beam profile monitor using a thin carbon fiber as a target. The beam is scanned with the wire target at the maximum speed of 5 m/s. The secondary particles from the beam-wire scattering are detected using a scintillation counter as a function of the wire position. The measurement has revealed a characteristic temporal change of the beam profile during the injection period of 120 ms. A multiparticle tracking simulation program, SCTR, taking account of space charge effects has successfully reproduced the beam profiles.  
 
TUPS057 Displacement of J-PARC Caused by Megaquake 1662
 
  • M.J. Shirakata, Y. Fujii, T. Ishii, Y. Shirakabe
    KEK, Tsukuba, Japan
  • H. Harada, S. Harjo, T. Iwahashi, S.I. Meigo, T. Morishita, N. Tani
    JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
 
  Accelerators, beam lines, and experimental halls located in the J-PARC site were displaced by the 2011 off the Pacific coast of Tohoku Earthquake happened on 11th March, whose magnitude was nine, and its following many aftershocks. Site-wide network of measurement points distributed on grounds, buildings, and magnets was surveyed by using GPS survey system, precise digital levels, and laser trackers. The effect from the megaquake was reported for each J-PARC components, such as LINAC, Rapid Cycling Synchrotron (RCS), Main Ring (MR), neutrino and hadron beam lines, and experimental halls.  
 
THPS035 Collimator Upgrade Plan of the J-PARC Main Ring 3496
 
  • M.J. Shirakata, K. Ishii, C. Kubota, T. Oogoe, J. Takano
    KEK, Ibaraki, Japan
  • Y. Kuniyasu
    MELCO SC, Tsukuba, Japan
  • Y. Takiyama
    JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
 
  A halo collimation system is prepared in the middle of injection-straight section in order to localize the beam loss occurred in main ring. It consists of three collimator units. The first unit scatters halo components, and the other two units work as halo catchers. The permitted amount of beam losses in the collimator section is designed to be 450 W at the present. The upgrade plan of halo collimation system is running in order to achieve about ten times larger beam loss capability for high-power beam operation. The collimator upgrade is planned by installing a new collimator set and radiation shields which cover the collimator section. New collimator units are designed to be able to line-out the jaw with a part of radiation shield including the mechanical devices. The design work of collimator units and radiation shields is presented in this report.