| Project/Area Number |
10640288
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
素粒子・核・宇宙線
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| Research Institution | Nagasaki Institute of Applied Science |
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Principal Investigator |
KIMURA Kikuo Department of engineering, Nagasaki Institute of Applied Science, Professor, 工学部, 教授 (60108636)
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| Project Period (FY) |
1998 – 1999
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| Project Status |
Completed (Fiscal Year 1999)
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| Budget Amount *help |
¥3,300,000 (Direct Cost: ¥3,300,000)
Fiscal Year 1999: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1998: ¥2,800,000 (Direct Cost: ¥2,800,000)
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| Keywords | RI beam / gas ionization chamber / multiple sampling detector / particle identification / 多重サンプリング型電離箱 / MUSIC検出器 / 不安定核ビーム |
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| Research Abstract |
A high-rate and stable particle identification detector for heavy ions was developed for using as a beam monitor in the unstable nuclear beam experiment like at the forthcoming RI-beam Factory. A multi-layered parallel plate gas ionization chamber having no grid was tried for this detector. The multi-layered configuration enables to make each unit of the chamber very thin and thus to operate it at high speed. However, because of the grid less construction, anode pulses of this ionization chamber are formed not only by the rapid current due to drifting electrons but also by the extremely show positive ion current. The existence of the latter current causes a great problem when operating at high rate. This problem was found to be avoided by applying the special pulse shaping to the anode pulses. The slowness of the positive ion current can be utilized to effectively reject the contribution of this current from the anode pulses. The multi-layered ionization chamber (high-rate MUSIC) thus constructed was tested using secondary beams containing various different heavy ions. It was found that the particle identification capability of this detector was almost equal to the limiting value determined by the statistical fluctuations of energy loss of the incident particles. That is to say, electric noises or detector properties did not at all affect it. The resolution can be improved indefinitely by increasing energy loss. As for the high-rate performance, no deterioration of the resolution was observed up to the maximum counting rate, 150kcps, of the test experiment. As a result of this, a highly practical detector could be developed.
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