FROM02 　粒子源　 8月10日 特別会議室２ 9:00 - 9:20

J-PARC MLF MUSEのミュオン生成標的の現状報告

Perspective of muon production target at J-PARC MLF MUSE

○牧村 俊助，的場 史朗，河村 成肇（KEK物構研、J-PARC）

○Shunsuke Makimura, Shiro Matoba, Naritoshi Kawamura (KEK-IMSS, J-PARC)

A pulsed muon beam with unprecedented intensity will be generated by a 3-GeV 333-microA proton beam on a muon target made of 20-mm thick isotropic graphite at J-PARC MLF MUSE (Muon Science Establishment). The energy deposited by a 1-MW proton beam is estimated to be 3.9kW in the muon target. The first muon beam was successfully generated on September 26th, 2008. Gradually upgrading the beam intensity, continuous 300-kW proton beam has been operated by a fixed target method without replacements till June of 2014. However, the lifetime of the fixed target will be less than 1 year by the proton-irradiation damage of graphite through 1-MW proton beam operation. To extend the lifetime, a muon rotating target, in which the radiation damage is distributed to a wider area, had been developed. The muon rotating target was installed in September of 2014, and continuous and stable 500-kW proton beam operation has been successfully performed. Recently, new developments of muon target for further higher power operation are in progress. The perspective of the muon production target at J-PARC MLF MUSE will be introduced in this presentation.