| Project/Area Number |
61420047
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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 |
Nuclear engineering
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| Research Institution | TOHOKU UNIVERSITY |
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Principal Investigator |
HIRAKAWA Naohiro Faculty of Engineering, Tohoku University, 工学部, 教授 (20005391)
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| Co-Investigator(Kenkyū-buntansha) |
IWASAKI Tomohiko Faculty of Engineering, Tohoku University, 工学部, 助手 (70184869)
BABA Mamoru Faculty of Engineering, Tohoku University, 工学部, 講師 (20005466)
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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 |
¥15,200,000 (Direct Cost: ¥15,200,000)
Fiscal Year 1988: ¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 1987: ¥4,000,000 (Direct Cost: ¥4,000,000)
Fiscal Year 1986: ¥9,200,000 (Direct Cost: ¥9,200,000)
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| Keywords | (n,2n) Cross Section / Statistical Analysis / Time interval / 3He Counter Bank / Be / Pb / (n,2n)中性子スペクトル / 遮蔽体 / コリメーター / 加速器 / 14MeV / 飛行時間法 / 中性子スペクトル / (n,3n)反応 / 核分裂中性子数 / 減子材 / ポリエチレン / モンテカルロコード / 中性子遮蔽 / タイムインターバル / 鉄 / 一次中性子スペクトル / 断面積 / 核融合炉材料 / 【^3He】カウンターバンク / 減速材 |
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| Research Abstract |
A new method has been developed to measure (n,2n) reaction cross sections which are of prime importance for development of fusion reactors. This method employs a 3He detector dank in which thirty 3He counters are embedded in polyethylene moderator to detect (n,2n) neutrons produced at the center, and the analysis of time interval between the detector signals to identify the (n,2n) events. This method has advantage of wide applicability and high detection efficiency.
1. we have performed design and fabrication of the detector system and its shielding using a Monte-Carlo neutron transport code with modification for the project, as well as the electronics for processing the detector signals and for derivation of time interval information.
2. An optimum arrangement of 3He counters was investigated using the code for best performance with respect to detection efficiency and neutron life time distribution. The moderator is of modular construction consisting of bricks to enable flexible operation responding various experimental requirement.
3. A data analysis code was developed to process the time interval data to deduce the (n,2n) cross section and its uncertainty.
4. In parallel, measurements and analyses were performed of neutron emission spectra from (n,2n) reaction which are indispensable for data analyses of 3He bank data. New data were obtained for several major nuclei in fusion application including Be.
5. The method successfully operated for (n,2n) cross section measurements around 14MeV for Be and Pb etc., and provided new data.
6. The detector and method proved to be useful for wide variety of measurements that are impractical by other technique.
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