Beam test of a new radio frequency quadrupole linac for the Japan Proton Accelerator Research Complex

Kondo, Yasuhiro   ; Morishita, Takatoshi  ; Yamazaki, Saishun; Hori, Toshihiko; Sawabe, Yuki; Chishiro, Etsuji; Fukuda, Shimpei; Hasegawa, Kazuo; Hirano, Koichiro  ; Kikuzawa, Nobuhiro ; Koizumi, Isao; Miura, Akihiko ; Oguri, Hidetomo  ; Okoshi, Kiyonori ; Sato, Fumiaki; Shinozaki, Shinichi ; Ueno, Akira  ; Kawamata, Hiroshi*; Sugimura, Takashi*; Takagi, Akira*; Fang, Z.*; Fukui, Yuji*; Futatsukawa, Kenta*; Ikegami, Kiyoshi*; Maruta, Tomofumi*; Miyao, Tomoaki*; Nammo, Kesao*

We performed a beam test of a new radio frequency quadrupole linac (RFQ III) for the beam current upgrade of the Japan Proton Accelerator Research Complex. First, the conditioning of RFQ III was conducted, and after 20 h of conditioning, RFQ III became very stable with a nominal peak power and duty factor of 400 kW and 1.5%, respectively. An off-line beam test was subsequently conducted before installation in the accelerator tunnel. The transmission, transverse emittance, and energy spread of the 50-mA negative hydrogen beam from RFQ III were measured and compared with simulation results. The experiment and simulation results showed good agreement; therefore, we conclude that the performance of RFQ III conforms to its design.