| Project/Area Number |
12640299
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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 | KEK, High Energy Accelerator Research Organization |
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Principal Investigator |
KOBAYASHI Masaaki KEK, IPNS, Professor, 素粒子原子核研究所, 教授 (40013388)
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| Co-Investigator(Kenkyū-buntansha) |
SUGIMOTO Shojiro KEK, IPNS, Professor, 素粒子原子核研究所, 教授 (20044753)
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| Project Period (FY) |
2000 – 2001
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| Project Status |
Completed (Fiscal Year 2001)
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| Budget Amount *help |
¥2,300,000 (Direct Cost: ¥2,300,000)
Fiscal Year 2001: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 2000: ¥1,300,000 (Direct Cost: ¥1,300,000)
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| Keywords | Cherenkov Detector / K / π Identification / K+Rare Decay Experiment / Lead Tungstate PbWO_4 / Silicon Strip Detector / Charge Preamplifier / ガンマ線検出器 / アクチヴ デグレーダー |
|---|
| Research Abstract |
We have developed a new heavy, fast-response, and radiation-hard Cherenkov radiators based on lead tungstate (PbWO4, PWO) by heavy doping with rare-earth 3+ ions (GD3+, La3+)
by a concentration of 3-8 mol%. We have confirmed the performance with the 500-1000 MeV/c π+ and proton beam at KEK-PS. The radiation hardness was measured for 60Co γ-rays at JAERI (Takasaki) for the accumulated dose of 1k-100k gray (1grey = 100rad).
We have also studied the effects of many other dopants in PWO and found that Th4+ ions by 〜100 mol ppm gives dramatical improvement to PWO similar to 3+ ions. A few dopants increase the light yield significantly for PET diagnosis with a time gate of a few hundred ns.
Another method to efficiently discriminate between K+ and π+ is to measure dE/dx precisely. We have carried out an R＆D of fast-readout and medium-segmented Si-strip detector (92x92 mm2) and readout pitch of 0.82 mm. This Si detector can withstand high intensity charged particles at a rate of 〜10MHz. The equivalent noise charge (ENC) well less than 3000e is promising for the K+ rare decay experiment (E949) at AG
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