Activation due to the charge exchange bean injection method in the J-PARC RCS

Yoshimoto, Masahiro; Yamakawa, Emi*; Takeda, Osamu; Yamamoto, Kazami; Harada, Hiroyuki; Saha, P. K.; Okabe, Kota; Kinsho, Michikazu

no journal, , 

In the 3 GeV Rapid Cycling Synchrotron (RCS) of the Japan Proton Accelerator Research Complex (J-PARC), we adopted the multi-turn charge exchange injection scheme using the stripper foils to achieve the high power proton beam. This injection scheme has the advantage of injecting the beam without limitation in number of bunched beam and without the beam loss in principle. Therefore it is adopted in the world high intensity proton beam accelerators. However, recent beam studies in the RCS make clear that this injection scheme causes the high radio activation around the stripper foil in spite of the reduction in the injection beam loss. In this presentation, we report the current status and the cause of the residual dose at the injection area in the RCS.