FRPI049  ハドロン加速器  8月2日 国際科学イノベーション棟5階 ホワイエ 10:50-12:50
Beam Loss Mitigation and Comissioning Progress at J-PARC linac
○劉 勇,大谷 将士,宮尾 智章,二ツ川 健太,南茂 今朝雄(高エネルギー加速器研究機構/J-PARC),伊藤 崇,森下 卓俊,田村 潤,岡部 晃大,守屋 克洋,三浦 昭彦(原研/J-PARC)
○Yong Liu, Masashio Otani, Tomoaki Miyao, Kenta Futatsukawa, Kesao Nanmo (KEK/J-PARC), Takashi Ito, Takatoshi Morishita, Jun Tamura, Kota Okabe, Katsuhiro Moriya, Akihiko Miura (JAEA/J-PARC)
J-PARC linac is now successfully operated at 50mA/400MeV for 500kW at neutron target, and promisingly on the way to 1MW. Beam loss at linac became one of the crucial issues. Simulation and experiment studies have been carried out to mitigated the intra-beam stripping (IBSt) effect in H- beam at 200~400 section, which was found to be the dominant source of beam loss at same type of accelerator. An IBSt-mitigation lattice with beam "temperature" ratio between transverse and longitudinal planes, T=0.7, away from the equipartition condition (T=1) followed by the J-PARC linac baseline design was carefully tested and selected to put into operation. Measured residue radiation dose verified the prediction of 40% reduction. Other recent progress of beam study in the commissioning will be also reported.