Author: Suganuma, K.
Paper Title Page
MOPPD053 Reduction of Outgassing from the Ferrite Cores in the Kicker Magnet of J-PARC RCS 487
  • N. Ogiwara, Y. Hikichi, J. Kamiya, M. Kinsho, M. Nishikawa, K. Suganuma, T. Yanagibashi
    JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
  Kicker magnets are used to kick out the accelerated beam to the beam transport lines in the RCS of the J-PARC. A high voltage is applied to kickers for a short period, so they must be installed in a vacuum to prevent discharge. Therefore, it is important to reduce the outgassing of water vapor from the ferrite cores. After bake-out at 200°C for 300 hours, the outgassing rate decreased to less than 1×10-7 Pam/s. However, the small amount of water vapor and carbon monoxide were emitted from the ferrite cores at charging voltage of 80 kV. This time, we have decided to construct the reserve magnets with very low outgassing at high-voltage discharge. First of all, the thermal desorption behavior of the ferrite was investigated. Water vapor has two peaks: at ~ 100°C and 350°C. Carbon monoxide is rather largely emitted until 300°C. From these results, the ferrite cores were vacuum-fired at 450°C for 10 h. Then the good properties for the magnetic cores were confirmed. And now the assembling of the kicker magnet is undertaken. The performance of the kicker magnet made of the vacuum-fired ferrite will be shown in this meeting.  
THPPD052 Operation and Current Status of Injection, Extraction, Kicker Magnet and the Power Supply for J-PARC 3 GeV RCS 3629
  • M. Watanabe, N. Hayashi, Y. Shobuda, K. Suganuma, T. Takayanagi, T. Togashi
    JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
  • T. Toyama
    J-PARC, KEK & JAEA, Ibaraki-ken, Japan
  3-GeV RCS (Rapid Cycling Synchrotron) at High Intensity Proton Accelerator Facility (J-PARC) have started for 24-hour operation with repetition rate of 25 pps in February, 2009. Kicker power supply system which uses thyratrons switches is used for extraction of the proton beam. There were many troubles for unstable operation of the thyratrons just after beam commissioning started. Recently, however, the operations were improved and the failure rate was reduced to approximately 0.1 % in October 2010. After the earthquake on March 11, 2011, the injection and extraction magnets, power supplies, the cables and the bus-duct have been checked. Insulation resistance test, impedance test were performed. Reflected wave measurements by the low-level and high-power pulse of the kicker magnets were performed. Visual checks by a fiber endoscope were also performed in the kicker magnets. The results of the measurements and the checks were all not in the problem.