Author: Kamiya, J.
Paper Title Page
WEPME020 Alignment Plan and Survey Results of the Equipment for J-PARC 3 GeV RCS 2971
  • N. Tani, H. Hotchi, J. Kamiya, M. Kinsho, O. Takeda, M. Yamamoto
    JAEA/J-PARC, Tokai-mura, Japan
  Misalignment of several millimeters of the magnets of J-PARC 3GeV RCS in both horizontal and vertical directions was caused by the Tohoku Region Pacific Coast Earthquake on March 11, 2011. As the result of orbit calculation showed that the beam loss was acceptable for beam operation at 300kW, beam operation with the current placement has been implemented. Realignment of the equipment will be carried out from August to December in 2013. Survey carried out in the summer of 2013 found out misalignment of ceramic vacuum ducts therefore their positioning is necessary. In this paper, these measurement result and latest alignment plan for J-PARC 3GeV RCS are reported.  
THPFI014 Bellows with a New RF Shield Made of Metal Braid for High Intensity Proton Accelerators 3321
  • N. Ogiwara, J. Kamiya, M. Kinsho, Y. Shobuda
    JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
  • O. Koizumi
    Sun-Tech limited, Kobe, Japan
  In the 3 GeV-RCS (Rapid cycling Synchrotron) in J-PARC (Japan Accelerator Research Complex) project, large-scale hydro-formed bellows were developed to adjust the gap between the ceramic ducts and/or between the ceramic ducts and the transport ducts. They have been equipped with a newly developed RF shield, because the usual beryllium-copper spring finger contacts were found to be very hard (roughly 1000 N/mm) owing to the large size. This contact is made of Ti braid, which consists of wires with a diameter of 0.3 mm. This RF contact is a kind of basket (with two ports) made with the braids. Because of the spring effect, the contact can change shape easily. In addition, the contact can easily connect the different cross sections in a smooth fashion. Furthermore, this structure is almost free from the dust generation, which is one of the most troublesome problems for the usual spring finger contacts. This time, we have constructed reserve bellows with the RF shield made of SUS 316L wires to improve the reliability of user operation. The outline of the bellows will be presented, especially laying emphasis on the mechanical function of the RF shield.  
THPFI015 In-situ Degassing of the Ferrite Cores in the Extraction Kicker Magnets of the J-PARC 3-GeV RCS 3324
  • J. Kamiya, Y. Hikichi, M. Kinsho, M. Nishikawa, N. Ogiwara, K. Suganuma, T. Yanagibashi
    JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
  Kicker magnets extract the accelerated beam to the beam transport lines in the RCS of the J-PARC. The kicker magnets mainly consist of Ni-Zn ferrite cores and Al alloy plates, and are installed in a vacuum to prevent discharge because a high voltage is applied for a short period. It is important to reduce the outgassing of water vapor from the ferrite cores. Although the kicker magnets have been working well, recently the vacuum quality became a little poor. Thus, we developed the in-situ degassing method for the ferrite cores. This is achieved by directing the heat from the heat source to the kicker magnet and not to the chamber wall. With the test stand we succeeded to flow almost all the heat toward the kicker magnet and to bake out the ferrite cores about 150°C, maintaining the temperature of the chamber wall less than 50°C. As the previous work with TDS measurements revealed that the absorbed water molecules can be easily removed by the bake-out at 100-150°C in a vacuum, the outgassing from the ferrite cores was successfully reduced. The details of the in-situ degassing method will be reported, including the practical method to reduce the outgassing of the working kickers.  
  • J. Kamiya, N. Hayashi, H. Hotchi, M. Kinsho, N. Ogiwara, N. Tani, Y. Watanabe
    JAEA/J-PARC, Tokai-mura, Japan
  which rapidly correct the tunes, are planned to be installed during the summer shutdown in 2013. The characteristic of the excitation pattern of such quadrupoles (quadrupole corrector) is their fast change of magnetic field, which are more than 200T/s at the fastest point. In this report, we describe a deliberation flow about the design of a vacuum chamber, which is installed in the quadrupole corrector. The effect of eddy current was calculated in the case of the current titanium vacuum chamber. The results showed that the temperature rise was too much (up to ~350oC) and the magnetic field in the vacuum chamber is largely distorted by the eddy current. Therefore we decided to employ an alumina ceramics vacuum chamber, for which we have a past achievement in RCS*. We estimated the displacement and stress, which is caused by the atmospheric pressure, for the alumina ceramics vacuum chamber and vacuum component around it by making the calculation model for the finite element method. It was found that there was no large displacement and stress by installing the alumina ceramics vacuum chamber.
*M. Kinsho, et al. Vacuum 81 (2007) 808.
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.