THAM4Y —  Parallel Session   (07-Jul-16   10:15—10:40)
Chair: T.J. Shea, ESS, Lund, Sweden
Paper Title Page
THAM4Y01 New Arrangement of Collimators of J-PARC Main Ring 1
 
  • M.J. Shirakata, S. Igarashi, K. Ishii, Y. Sato, J. Takano
    KEK, Ibaraki, Japan
 
  The beam collimation system of J-PARC main ring has been prepared in order to localize the beam loss into the specified area, especially during the injection period. At the first time, it was constructed as a scraper-catcher system in horizontal and vertical planes which consisted of one halo-scraper and two scattered protons catchers, whose the maximum beam loss capacity was designed to be 450W in the beam injection straight of the ring. In 2012, the scraper was replaced by two collimators with a movable L-type jaw for both planes. Two catchers remained at the same places, and they were used as collimators. This large change of design concept of main ring collimation system was required in order to increase the beam loss capacity more than 3kW. The system worked well but unexpected loss spots still remained in the following arc and straight sections. The four-axis collimator was developed with movable jaw in horizontal, vertical and skew configurations which has high cleaning efficiency. We have four four-axis collimators, two non-skew collimators, and one original catcher. The most effective arrangement of collimators was investigated in this report.  
slides icon Slides THAM4Y01 [2.426 MB]