Beam fast extraction tuning of the J-PARC main ring

J-PARC MRにおける出射部のチューニング

Wei, G.; 小関 忠*; 冨澤 正人*; 五十嵐 進*; 石井 恒次*; 安東 愛之輔; 高野 淳平*; 魚田 雅彦*; Fan, K.*; 畠山 衆一郎; 中平 武*; 原田 寛之  ; Saha, P. K.   

Wei, G.; Koseki, Tadashi*; Tomizawa, Masahito*; Igarashi, Susumu*; Ishii, Koji*; Ando, Ainosuke; Takano, Jumpei*; Uota, Masahiko*; Fan, K.*; Hatakeyama, Shuichiro; Nakadaira, Takeshi*; Harada, Hiroyuki; Saha, P. K.

The beam commissioning of J-PARC/MR has been started from May 2008 and is in good progress. One key purpose of MR commissioning is the 30 GeV beam fast extraction to neutrino beam line, which reflect the overall commissioning result. In the MR, fast extraction system comprises 5 kickers and 8 septa which give a bipolar kick to neutrino beam line or abort dump. However before commissioning, the measured magnetic field distribution of each fast extraction septa shows non-linear profile along the horizontal direction. In order to find the influence, a beam simulation with the measured field distributions of septa has been performed. Depends on this study and some OPI (Operation Interface) made by code SAD for orbit modification online, fast extraction of 30 GeV beam to neutrino beam line has been achieved on April 23rd 2009. And so far, 100 kW continual operation to neutrino line have been achieved, too.