Author: Someya, H.
Paper Title Page
WEPPR052 Octupole Magnets for the Instability Damping at the J-PARC Main Ring 3045
  • S. Igarashi, T. Koseki, K. Ohmi, M.J. Shirakata, H. Someya, T. Toyama
    KEK, Ibaraki, Japan
  • A. Ando
    J-PARC, KEK & JAEA, Ibaraki-ken, Japan
  Octupole magnets have been installed for the instability damping at the J-PARC main ring. The transverse instability was observed during the injection and acceleration periods and caused the beam losses. The chromaticity tuning and bunch-by-bunch feedback system have been applied to suppress the instability. Octupole magnets were considered to create a larger amplitude dependent betatron tune shift and to supply additional option for the instability damping. The side effects of the dynamic aperture reduction and the resonances have been studied.  
THPPP004 Design and Test of Injection Kicker Magnets for the JPARC Main Ring 3728
  • K. Fan, S. Fukuoka, K. Ishii, H. Matsumoto, H. Someya, T. Sugimoto, T. Toyama
    KEK, Ibaraki, Japan
  The present injection kicker magnets of the JPARC main ring consists of three transmission type kickers. To overcome the operational problems, four lumped inductance kicker magnets have been developed for the simplicity and the high reliability. The tight requirements on the rise and fall time create difficulties for the new design. Magnetic field measurements, coupling impedance measurements and have been carried out. The measurement results show that the new kicker magnets can satisfy the requirements of beam injection.