| Project/Area Number |
12650054
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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 |
Applied physics, general
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| Research Institution | The University of Tokushima |
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Principal Investigator |
KOORI Norihiko The Univ. of Tokushima, Fac. Integrated Arts and Sci., Prof., 総合科学部, 教授 (20038053)
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| Co-Investigator(Kenkyū-buntansha) |
FUSHIMI Ken-ichi The Univ. of Tokushima, Fac. Integrated Arts and Sci., Asso. Prof., 総合科学部, 助教授 (90274191)
NAKAYAMA Shintaro The Univ. of Tokushima, Fac. Integrated Arts and Sci., Professor, 総合科学部, 教授 (70116846)
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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 |
¥3,700,000 (Direct Cost: ¥3,700,000)
Fiscal Year 2001: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 2000: ¥3,200,000 (Direct Cost: ¥3,200,000)
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| Keywords | scintillators / low background / GSO / scintillation mechanism / environmental neutron / pulse shape analysis |
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| Research Abstract |
In this research, highly sensitive neutron monitors are intended to be realized for measurements of environmental neutrons with GSO (Gd_2SiO_5 : Ce) scintillators. The scintillator with Gd- 157, which has a very high cross section of 254,000 b for thermal neutron capture, may be a high sensitivity neutron monitor. Followings are the results from the present research.
(1) Neutron detection with a GSO scintillators : The GSO scintillator response were observed for thermal neutrons. Gamma-rays of 79.5 keV and 182 keV from Gd-158 resulted by the thermal neutron capture were confirmed with a low intensity neutron source, and then a high detection efficiency of 14 % was obtained for a 2" Φ x 2" GSO crystal. Applications will be planed to measurement of very low flux of environmental neutrons will be possible with a good shield condition of Pb, Oxigen-free Cu, and Paraffin blocks.
(2) Pulse shape of scintillation from a GSO scintillators : The pulse shapes of scintillation combining with the pulse height determination were measured with a high speed digital oscilloscope. A pulse shape analyzing system were developed for this purpose, and measured the decay times of scintillation from GSO crystals of different Ce concentrations, and other LSO, BGO and BaF_2 scintillation crystals. The developed pulse shape analyzing system will be effective for discrimination of alphas from contaminants of U-series nuclei in crystals.
The present research provides the knowledge about a high sensitive neutron monitor of GSO scintillators,
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