Speaker
Mr
Yusuke Komatsu
(University of Tokyo)
Description
The J-PARC E16 experiment measures the mass modification of phi meson in nuclear matter at J-PARC high-momentum beam line to study an origin of hadron mass. The tracking detector of the experiment is composed of three layers of position sensitive devices that employ 10 cm x 10 cm, 20 cm x 20 cm and 30 cm x 30 cm Gas Electron Multipliers (GEMs) and two-dimensional readout boards. Required position resolution is 100 μm upto the incident angle of 30°.
We have successfully generated all sizes of GEM foils using a wet-etching method in Japan. The avalanche gain is tested with 55Fe X-ray source to check the healthiness of the foils and the gain of 10^4 is achieved for all the sizes.
Position resolution and efficiency are evaluated in the beam test. Position resolution of better than 100 μm is obtained for 0°incident angle by calculating the weighted mean of charge. Inclined tracks have worse resolutions using the same method. Thus, we have developed a new technique to measure a position using arrival timing information of generated charge clusters in a drift gap. Arrival timings are measured by the timings of signals from read-out strips. Timing information is converted to a cluster generated position in the drift gap using a known drift velocity. Cluster generated positions are fitted by a linear function and a hit position can be calculated by a fitting result. As a result, position resolution of 105 μm is obtained for 15°beam by the timing analysis.
| quote your primary experiment | J-PARC E16 |
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Primary author
Mr
Yusuke Komatsu
(University of Tokyo)
Co-authors
Dr
Daisuke Kawama
(RIKEN)
Mr
Kouki Kanno
(University of Tokyo)
Prof.
Kyoichiro Ozawa
(KEK)
Dr
Michiko Sekimoto
(KEK)
Dr
Satoshi Yokkaichi
(RIKEN)
Mr
Shinichi Masumoto
(University of Tokyo)
Mr
Takuya Shibukawa
(University of Tokyo)
Mr
Tomonori Takahashi
(RIKEN)
Mr
Wataru Nakai
(University of Tokyo)
Dr
Yoki Aramaki
(RIKEN)
Mr
Yosuke Watanabe
(University of Tokyo)
Mr
Yuki Obara
(University of Tokyo)
