TUAM6Y —  Parallel Session   (05-Jul-16   11:25—11:50)
Chair: M. Ikegami, FRIB, East Lansing, Michigan, USA
Paper Title Page
TUAM6Y01
Experimental Investigation of Emittance Exchange in J-PARC Linac With Non-Equipartitioning Setting  
 
  • Y. Liu
    KEK/JAEA, Ibaraki-Ken, Japan
  • M. Ikegami
    FRIB, East Lansing, Michigan, USA
  • T. Maruta
    J-PARC, KEK & JAEA, Ibaraki-ken, Japan
  • A. Miura
    JAEA/J-PARC, Tokai-mura, Japan
  • T. Miyao
    KEK, Ibaraki, Japan
  • D.C. Plostinar
    STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom
 
  J-PARC is on the way to 1 MW operation step by step. J-PARC linac complected upgrade to 50 mA/400MeV in 2014, and the next main tasks of beam study are to optimize beam loss and output emittance for 40 mA and 50 mA operation. Residue radiation level at a lower repetition predicted that the beam loss becomes close to the maintenance limit in case of full operation at 50 mA. And intra-beam stripping (IBSt) effect in the H beam is found to be the dominant source of the beam loss here. IBSt is only sensitive to lattice, so that the only solution is to be away from J-PARC baseline design with equipartitioning condition, in a safe way. In the previous work, emittace exchange and break of periodicity were predicted by the simulation and they are consistent with the "Hofmann chart". Series of experiments were carried out, not only for investigation of new lattice with controlled beam loss and emittance but also for a better understanding of rules of lattice optimization and the physics behind.  
slides icon Slides TUAM6Y01 [3.159 MB]