Author: Takagi, M.
Paper Title Page
TUPC103 Monitoring of the Betatron Tune and Amplitude at Multi-batch Injection of J-PARC MR 1254
 
  • S. Hatakeyama
    JAEA/J-PARC, Tokai-mura, Japan
  • M. Takagi
    Kanto Information Service (KIS), Accelerator Group, Ibaraki, Japan
  • M. Tejima, T. Toyama
    KEK, Ibaraki, Japan
 
  The beam power of J-PARC Main Ring Synchrotron (MR) increased gradually from 2008, and came to be able regularly to supply the beam of 145kW February, 2011. Many of current beam losses are localized to the collimator located on the injection section. One of the problems of the beam injection is that the orbit of the beam transportation line is unstable. It causes sometimes large transverse injection error. Because the transverse injection error is essentially proportional to the amplitude of the betatron oscillation, it is possible to observe by measuring the turn-by-turn position for every bunch of injected beam by using BPMs located on the injection section. In this report, it is described the method how to measure injection error from beam position. It is also discussed about the effect of reflection wave of injection kicker magnets.