Author: Igarashi, S.
Paper Title Page
TUPME012 Space Charge Simulation based on a Measured Optics in J-PARC MR 1589
 
  • K. Ohmi, S. Igarashi, Y. Sato, J. Takano
    KEK, Ibaraki, Japan
  • S. Hatakeyama
    JAEA/J-PARC, Tokai-mura, Japan
 
  Linear optics parameters, beta, alpha, phase, x-y coupling and dispersion are measured by phase space monitor and/or other tools. Nonlinear effects due to the space charge and magnets are dominantly determined by linear optics. For example, the beam distribution is mainly determined by linear optics, and error of beta function at a sextuple magnet is larger than error of magnet strength generally. This means space charge simulation based on the measured optics takes into account of the major part of errors. We discuss how beam loss degrade and which resonances are induced by the errors in the simulations.  
 
WEPEA015 Possibility Study of High Repetition Rate Operation of JPARC Main Ring 2528
 
  • K. Fan, S. Igarashi, K. Ishii, T. Koseki, M. Uota
    KEK, Ibaraki, Japan
 
  The original design of JPARC main ring is to provide high beam power of 750 kW with machine repetition rate of 0.3 Hz. However, the severe space charge effects at low injection energy limit the beam intensity. In order to raise the beam power to the design limit, one logical way is to increase the repetition rate. However, the resulting eddy current in the laminations and pipes may impair the field quality of all magnets. In addition, the activation of beam pipe becomes severer in high beam power operation. Titanium beam pipe is proposed to replace the stainless steel pipe to reduce the activation and decrease the decay time. However, titanium has lower resistivity, severer eddy current effects are expected. The studies investigate the eddy current effects on field quality of the main dipole, quadrupole and sextupole magnets.