Development of negative muonium ion source for muon acceleration

Kitamura, Ryo   ; Bae, S.*; Choi, S.*; Fukao, Yoshinori*; Iinuma, Hiromi*; Ishida, Katsuhiko*; Kawamura, Naritoshi*; Kim, B.*; Kondo, Yasuhiro   ; Mibe, Tsutomu*; Miyake, Yasuhiro*; Otani, Masashi*; Razuvaev, G. P.*; Saito, Naohito; Shimomura, Koichiro*; Strasser, P.*

A negative muonium ion (Mu) source using an aluminum foil target was developed as a low-energy muon source. An experiment to produce Mu ions was conducted to evaluate the performance of the Mu ion source. The measured event rate of Mu ions was Mu/s when the event rate of the incident muon beam was /s. The formation probability, defined as the ratio of the Mu ions to the incident muons on the Al target, was . This Mu ion source boosted the development of the muon accelerator, and the practicality of this low-energy muon source obtained using a relatively simple apparatus was demonstrated.