Re-acceleration of ultra cold muon in J-PARC Muon Facility

Kondo, Yasuhiro   ; Hasegawa, Kazuo; Morishita, Takatoshi  ; Otani, Masashi*; Futatsukawa, Kenta*; Kawamura, Naritoshi*; Mibe, Tsutomu*; Yamazaki, Takayuki*; Yoshida, Mitsuhiro*; Kitamura, Ryo*; Nakazawa, Yuga*; Iinuma, Hiromi*; Sue, Yuki*; Hayashizaki, Noriyosu*; Iwashita, Yoshihisa*; Iwata, Yoshiyuki*; Saito, Naohito; 13 of others*

J-PARC is developing the reacceleration system of the ultra slow (30 meV) muon (USM) obtained by two-photon laser resonant ionization of muonium atoms. The muon beam thus obtained has low emittance, meeting the requirement for the g-2/EDM experiment. J-PARC E34 experiment aims to measure the muon anomalous magnetic moment (g-2) with a precision of 0.1 ppm and search for EDM with a sensitivity to e cm. The USM's are accelerated to 212 MeV by using a muon dedicated linac to be a ultra cold muon beam. The muon LINAC consists of an RFQ, a inter-digital H-mode DTL, disk and washer coupled cell structures, and disk loaded structures. Proof of the slow muon acceleration scheme is an essential step to realize the world first muon linac. In October 2017, we have succeeded to accelerate slow negative muoniums generated using a simpler muonium source to 89 keV. In this talk, present design of the muon linac and the result of the world first muon acceleration experiment are reported.