Author: Nishiguchi, H.
Paper Title Page
TUPC099 New Measurements of Proton Beam Extinction at J-PARC 1242
 
  • K. Yoshimura, Y. Hori, Y. Igarashi, S. Mihara, H. Nishiguchi, Y. Sato, M. Shimamoto, Y. Takeda, M. Uota
    KEK, Ibaraki, Japan
  • M. Aoki, S. Hikida, H. Nakai
    Osaka University, Osaka, Japan
  • Y. Hashimoto
    J-PARC, KEK & JAEA, Ibaraki-ken, Japan
  
  Pro­ton beam ex­tinc­tion, de­fined as a resid­u­al to pri­ma­ry ratio of beam in­ten­si­ty, is one of the most im­por­tant pa­ram­e­ters to re­al­ize the fu­ture muon elec­tron con­ver­sion ex­per­i­ment (COMET) pro­posed at J-PARC. To achieve the re­quired ex­tinc­tion level of 10-9, we start­ed mea­sur­ing ex­tinc­tion at main ring (MR) as its first step. Ac­cord­ing to the var­i­ous mea­sure­ments done at the dif­fer­ent po­si­tions, empty RF buck­ets of RCS, which were con­sid­ered to be swept away by the RF chop­per, con­tained about 10-7 ~ 10-5 of the main beam pulse due to chop­per in­ef­fi­cien­cy. We have de­vel­oped a new beam mon­i­tor with im­proved per­for­mance for fur­ther stud­ies at the abort line. In ad­di­tion, we have start­ed new mea­sure­ments at the Hadron ex­per­i­men­tal hall by using slow-ex­tract­ed beam. In this paper, we pre­sent re­cent re­sults and fu­ture prospect of beam ex­tinc­tion mea­sure­ments.