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Shobuda, Y.

Paper Title Page
MPPE005 Dynamic Aperture and Resonance Correction for JPARC-RCS 979
 
  • A.Y. Molodojentsev, E. Forest, S. Machida
    KEK, Ibaraki
  • H. Hotchi, F. Noda, M.J. Shirakata, Y. Shobuda, H. Suzuki, K. Yamamoto
    JAERI/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
  • Y. Ishi
    Mitsubishi Electric Corp, Energy & Public Infrastructure Systems Center, Kobe
 
  Main intrinsic field nonlinearities, which are common for synchrotrons with large aperture, are the nonlinear field of the bending magnets, the fringing field of the magnets and the sextupole field nonlinearity, used for the chromaticity correction. The particle motion in the ring bending magnets has been analyzed by two methods: (1) by direct integration of the particle motion equations in the 3D magnetic field (Tosca output), based on the 4th order Runge-Kutta integrator and (2) by determination the transfer 8th order map of the bending magnet by using the Gaussian wavelet in the 3D space. The second technique allows us to use powerful tools such as the normal form analysis, to define the resonance driving terms, which can be used for the resonance correction. As the result of this study it was shown that the main limitation of the RCS dynamic aperture can be caused by the structure normal sextupole-order resonance and the normal octupole-order resonance. Other high-order resonances have smaller effects on the particles motion than the resonances mentioned above. The correction scheme to improve the dynamic aperture near the normal sextupole-order resonance has been analyzed.  
MPPE043 The Status of Optics Design and Beam Dynamics Study in J-PARC RCS 2759
 
  • F. Noda, N. Hayashi, H. Hotchi, J. Kishiro, P.K. Saha, Y. Shobuda, K. Yamamoto
    JAERI/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
  • S. Machida, A.Y. Molodojentsev
    KEK, Ibaraki
 
  The 3GeV RCS at J-PARC is designed to provide proton beam of 3GeV and a goal of output beam power is 1MW. The beam commissioning starts on May 2007. At present, more qualitative studies concerning beam dynamics are in progress: core beam handlings, halo beam handlings, instabilities and so on. In this paper, the RCS optics design and the present status of beam dynamics studies are summarized.  
MPPP025 The Impedance of the Ceramic Chamber in J-PARC 1898
 
  • Y. Shobuda
    JAERI/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
  • Y.H. Chin, K. Ohmi, T. Toyama
    KEK, Ibaraki
 
  The ceramic chamber is adopted at the RCS (rapid cycling synchrotron) in J-PARC. The copper stripes are on the outer surface of the chamber in order to shield the electro-magnetic field produced by the beam. The inner surface of the chamber is coated by TiN to suppress the secondary electron emission. In this paper, we calculate the strength of electro-magnetic field produced by the beam and evaluate the impedance of this ceramic chamber.