| Project/Area Number |
03452020
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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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 | University of Tokyo |
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Principal Investigator |
MINOWA Makoto University of Tokyo, School of Science, Associate Professor, 理学部, 助教授 (90126178)
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| Co-Investigator(Kenkyū-buntansha) |
WATANABE Takayuki University of Tokyo, School of Science, Research Associate, 理学部, 助手 (80202414)
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| Project Period (FY) |
1991 – 1992
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| Project Status |
Completed (Fiscal Year 1992)
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| Budget Amount *help |
¥6,600,000 (Direct Cost: ¥6,600,000)
Fiscal Year 1992: ¥3,000,000 (Direct Cost: ¥3,000,000)
Fiscal Year 1991: ¥3,600,000 (Direct Cost: ¥3,600,000)
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| Keywords | Cooled Scintillator / Cesium Iodide / Lead Molybdate / Lead Tungstate / Dark Matter / Double Beta Decay / シンチレータ / 低温 / タングステン鋼鉛 / シンチレ-タ / 二重ベ-タ崩壊 / シリコンフォトダイオ-ド / モリブデン配鉛 / 液体窒素温度 / ド-プ |
|---|
| Research Abstract |
We confirmed that an undoped cesium iodide crystal is a very efficient scintillator if it is cooled down to the liquid nitrogen temerature.
We newly found that a cooled monocrystal of lead molybdate also functions as a scintillator at temperature below 100K.Since it contains molybdenum-100, a double beta decay nuclide, it may open new perspective of the double beta decay experiments. We performed a short term experiment with this crystal for the evaluation, and obtained 8.9*10^<17> for the lower limit of the half life of ^<100>Mo double beta decay. We also found that lead-210 impurity in the crystal is the limitting factor of the experiment.
A lead tungstate, similar material to the lead molybdate, is found to be also a scintillator below 100K.
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