Development of Particle Identification Apparatus for the Experiment of Heavy Quark Decay
| Project/Area Number |
61420008
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| Research Category |
Grant-in-Aid for General Scientific Research (A)
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| Allocation Type | Single-year Grants |
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| Research Field |
核・宇宙線・素粒子
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| Research Institution | Kobe University |
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Principal Investigator |
FUJII Tadao Dept. of Physics, Faculty of Science, Kobe Univ. Professor, 理学部, 教授 (50013355)
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| Co-Investigator(Kenkyū-buntansha) |
TAKAHASHI Yoshiki Graduate School of Science & Technology, Kobe Univ Research Asscciate, 自然科学研究科, 助手 (00183856)
HOMMA Yasuhiro School of Allied Medical Science, Kobe Univ. Asscciate Professor, 医療技術短期大学部, 助教授 (90107988)
YOKOYAMA Chiaki Dept. of Physics, Faculty of Science, Kobe Univ. Technical Official, 理学部, 教務職員 (30093537)
FUKUSHIMA Hiroshi Dept. of Physics, Faculty of Science, Kobe Univ. Associate Professor, 理学部, 助教授 (30030779)
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| Project Period (FY) |
1986 – 1988
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| Project Status |
Completed (Fiscal Year 1988)
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| Budget Amount *help |
¥33,500,000 (Direct Cost: ¥33,500,000)
Fiscal Year 1988: ¥3,000,000 (Direct Cost: ¥3,000,000)
Fiscal Year 1987: ¥5,100,000 (Direct Cost: ¥5,100,000)
Fiscal Year 1986: ¥25,400,000 (Direct Cost: ¥25,400,000)
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| Keywords | Charm and Bottom Particles / Transition Radiation Detector / 電子識別 / 遷輻射検出器 |
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| Research Abstract |
We have developed a large transition radiation detector(TRD) to improve the detection efficiency for high P_t electrons in the heavy quark decay. Firstly, several radiators with different materials and thickness were constructed and a small Xe gas multiwire proportional chamber(MWPC) was developed for X-ray detection. This prototype TRD was tested in the mixed /e beam of a few Gev/c at KEK-PS to find that the best radiator was 350 layers of 18 m polypropylene(pp) foil and the intensity of TR from many layers was saturated above 3 Gev/c.
Based on these results, we proceeded to design and construct a real-size TRD with an effective area of 60 cm square. There we had to solve several problems associated with enlargement of TRD. In order to attain an uniform density in the radiator, the pp foil was thermally deformed to produce many humps uniformly over the surface. This method enabled us to pile up many layers with a constant gap. In a large MWPC, the density difference between Xe and air tends to produce non-uniform electric fields. To elliminate this undesirable effect, a slab of styroform was pressed against an aluminized mylar cathode with a help of a nitrogen bag. With this method, a planarity of cathode was main-tained within 10 m, which corresponds to the gain variation of 0.6%. This real-size TRD was again tested in the /e beam at KEK-PS. The contamination was improved to be less than 3.5% for the electron detection efficiency of 90% with 4 TRDs in series. This rejection ability was also uniform over the ffective area of of 60 cm square.
Thus we have succeeded to develop a large TRD with an uniform /e rejection ability to be used in a real experiment.
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Report
(4 results)
Research Products
(11 results)
