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Sako, Hiroyuki; Hwang, S.; Ichikawa, Yudai; Imai, Kenichi; Sato, Susumu; Sugimura, Hitoshi
Proceedings of Science (Internet), 213, p.300_1 - 300_4, 2015/07
We develop a TPC (Time Projection Chamber) using GEM (Gas Electron Multiplier) to search for H-dibaryon at J-PARC E42 experiment. We evaluated performance of a small prototype TPC. We performed a long term operation test for one month which is similar term as E42. We suppressed hit position distortion with 
0.2 mm due to ion backflow.
Konstantinova, O.*; Sako, Hiroyuki; Maruta, Tomofumi*; Miura, Akihiko
Proceedings of Science (Internet), 213, p.083_1 - 083_8, 2015/07
The highest beam loss has been observed at the ACS (Annular Coupled Structure) section in the J-PARC linac. We have developed a scintillating fiber detector for beam loss proton measurements at J-PARC linac. It consists of 4 upstream fiber planes and 4 downstream fiber planes. The upstream and downstream planes are separated by 1.6 m for time-of-flight measurements. A charged particle which passes through the 8 planes are either a proton or an electron, which can be distinguished by time-of-flight. We measured the absolute proton beam loss rates of 1.8-3.2
10
. The ratio of H
/H
was 0.7-1.810
, which is closed to the estimated value of 2.710 from residual gas pressure. The energy of protons was measured to be 80-120 MeV, which was consistent with the average simulated value of 90 MeV.
