2000 Fiscal Year Annual Research Report

超強力パルス中性子源開発に関する共同研究

Research Project

Project/Area Number	11694111
Research Institution	Hokkaido University
Principal Investigator	鬼柳善明北海道大学, 大学院・工学研究科, 教授 (80002202)
Co-Investigator(Kenkyū-buntansha)	平賀富士夫北海道大学, 大学院・工学研究科, 助手 (00228777) 加美山隆北海道大学, 大学院・工学研究科, 助教授 (50233961) 成田正邦秋田大学, 工学資源学部, 教授 (00001313) 渡辺昇日本原子力研究所, 中性子科学研究センター, 特別研究員古坂道弘高エネルギー加速器研究機構, 物質構造科学研究所, 教授 (60156966)
Keywords	スポレーション中性子源 / 中性子減速材 / 液体水素 / プレモデレータ / 複合型減速材
Research Abstract	メガワット級のパワーを持った陽子加速器を使うスポレーション中性子源では,遅い中性子を生成するための減速材として,液体水素が最も現実的な選択と考えられている.しかし,液体水素は水素数密度が低いために,中性子が減速途中で漏れる割合が高い.そのため,得られる遅い中性子の強度が低くなる.それを,改善する方法として,中性子発生ターゲットから放出される高エネルギー中性子を,水素減速材に入射する前に,あらかじめ減速(プレモデレート)してしまったらどうかということを試した.この方法は,減速材周りに取り付ける中性子反射体があまり中性子を減速しない場合に有効であると考えられる.鉛を反射体とし,プレモデレータとして軽水と重水を用いて測定を行なった.その結果,プレモデレータをつけることによって,中性子強度が1.3〜1.8倍大きくなること,また,重水が軽水よりも多少強度がおおきいこと,中性子放出時間分布にはあまり影響を与えないことが分かった.同時に,数値シミュレーションを行なったが,計算では増加率が倍近く大きくなることが分かった. 別の方法として,水素と軽水を層状に重ねて,軽水の水素数密度の高さを利用して水素の特性を改善することを考えた(複合型減速材).この方法によって,液体水素単体よりも中性子強度を増やすことができることが分かった.このことは,軽水がある意味でプレモデレータとして働いていることを示している.しかし,放出時間分布が,水がある分広くなることが分かった.この減速材は,強度だけを重要視する実験には向いているが,エネルギー分解能を重要視する実験には向いていないことが分かった. この後,さらに液体水素のオルソ・パラ成分比による中性子特性の違いについて詳しく検討していく予定である.また,実際のスポレーション中性子源における特性測定や重要な遮蔽実験も行なう予定である.

Research Products

(17 results)

All Other

All Publications (17 results)

[Publications] Y.Ogawa: "Measurements of Neutronic Performance on a Mixed Cold Moderator of Polyethylene Particles and Liquid-Hydrogen"Journal of Nuclear Science Technology. Vol36, No.1. 105-107 (1999)
[Publications] Y.Ogawa: "Intensity enhancement of cold neutrons from a coupled liquid-hydrogen moderator for pulsed cold neutron sources"Nuclear Instrument and Methods in Physics Research. A432. 415-421 (1999)
[Publications] M.Arai: "Neutron Production from Lead Targets for 12-GeV Protons"Journal of Neutron Research. Vol.8. 71-83 (1999)
[Publications] Y.Kiyanagi: "Optimization of pulse shape"ICANS-XV : Proceedings of the 15^<th> Meeting of the International Collaboration on Advanced Neutron Sources. (to be published).
[Publications] M.Kawai: "Renewal of KENS TMRA"ICANS-XV : Proceedings of the 15^<th> Meeting of the International Collaboration on Advanced Neutron Sources. (to be published).
[Publications] M.Ooi: "Premoderator and Reflector Effect on the Neutronic Performance of a Decoupled Liquid Hydrogen Moderator"ICANS-XV : Proceedings of the 15^<th> Meeting of the International Collaboration on Advanced Neutron Sources. (to be published) .
[Publications] T.Ino: "Measurements of Neutronic Characteristics of the KENS Target-Moderator-Reflector Assembly"ICANS-XV : Proceedings of the 15^<th> Meeting of the International Collaboration on Advanced Neutron Sources . (to be published).
[Publications] K.Sasaki: "Experimental Studies on Neutronics of CH_3D and HD Cold Neutron Moderators"ICANS-XV : Proceedings of the 15^<th> Meeting of the International Collaboration on Advanced Neutron Sources. (to be published).
[Publications] E.V.Iverson: "Neutronic Studies of a liq.H_2-H_2O Composite Moderator"ICANS-XV : Proceedings of the 15^<th> Meeting of the International Collaboration on Advanced Neutron Sources. (to be published).
[Publications] M.Ooi: "Calculational Studies of a Multi-Layer Decoupler System for a Decoupled Hydrogen Moderator"ICANS-XV : Proceedings of the 15^<th> Meeting of the International Collaboration on Advanced Neutron Sources. (to be published).
[Publications] H.Noda: "Pulse Shape Measurement of KENS Thermal Neutron Source in the eV Region by N-RAS"ICANS-XV : Proceedings of the 15^<th> Meeting of the International Collaboration on Advanced Neutron Sources. (to be published).
[Publications] Gary J.Russell: "Neutron Beam Line Shield Design for the Protein Crystallography Instrument"ICANS-XV : Proceedings of the 15^<th> Meeting of the International Collaboration on Advanced Neutron Sources. (to be published).
[Publications] Gary J.Russell: "Overview of Spallation Neutron Source Physics"the Proceedings of the Workshop on Fundamental Physics with Pulsed Neutron Beams. (2000)
[Publications] P.D.Ferguson: "Re-analysis of the Belyakov-Bodin Energy Deposition Experiment Using MCNPX"the proceedings of AccApp 2000. (to be published) .
[Publications] K.Corzine: "MCNPX Benchmarks of In- and Out-of-Beam Energy Deposition for 800-Me V Protons"the proceedings of AccApp 2000. (to be published).
[Publications] R.S.Lillard: "The Effects of High Energy Proton Radiation on the Corrosion of Materials"ASTM STP 1405.
[Publications] Gary J.Russell: "The Lujan Center : A Pulsed Spallation Neutron Source at Los Alamos"the Proceedings of ICONE-8. ICONE-8611. 1-12 (2000)

2000 Fiscal Year Annual Research Report

超強力パルス中性子源開発に関する共同研究

Principal Investigator

鬼柳 善明 北海道大学, 大学院・工学研究科, 教授 (80002202)

Research Products

[Publications] Y.Ogawa: "Measurements of Neutronic Performance on a Mixed Cold Moderator of Polyethylene Particles and Liquid-Hydrogen"Journal of Nuclear Science Technology. Vol36, No.1. 105-107 (1999)

[Publications] Y.Ogawa: "Intensity enhancement of cold neutrons from a coupled liquid-hydrogen moderator for pulsed cold neutron sources"Nuclear Instrument and Methods in Physics Research. A432. 415-421 (1999)

[Publications] M.Arai: "Neutron Production from Lead Targets for 12-GeV Protons"Journal of Neutron Research. Vol.8. 71-83 (1999)

[Publications] Y.Kiyanagi: "Optimization of pulse shape"ICANS-XV : Proceedings of the 15^<th> Meeting of the International Collaboration on Advanced Neutron Sources. (to be published).

[Publications] M.Kawai: "Renewal of KENS TMRA"ICANS-XV : Proceedings of the 15^<th> Meeting of the International Collaboration on Advanced Neutron Sources. (to be published).

[Publications] M.Ooi: "Premoderator and Reflector Effect on the Neutronic Performance of a Decoupled Liquid Hydrogen Moderator"ICANS-XV : Proceedings of the 15^<th> Meeting of the International Collaboration on Advanced Neutron Sources. (to be published) .

[Publications] T.Ino: "Measurements of Neutronic Characteristics of the KENS Target-Moderator-Reflector Assembly"ICANS-XV : Proceedings of the 15^<th> Meeting of the International Collaboration on Advanced Neutron Sources . (to be published).

[Publications] K.Sasaki: "Experimental Studies on Neutronics of CH_3D and HD Cold Neutron Moderators"ICANS-XV : Proceedings of the 15^<th> Meeting of the International Collaboration on Advanced Neutron Sources. (to be published).

[Publications] E.V.Iverson: "Neutronic Studies of a liq.H_2-H_2O Composite Moderator"ICANS-XV : Proceedings of the 15^<th> Meeting of the International Collaboration on Advanced Neutron Sources. (to be published).

[Publications] M.Ooi: "Calculational Studies of a Multi-Layer Decoupler System for a Decoupled Hydrogen Moderator"ICANS-XV : Proceedings of the 15^<th> Meeting of the International Collaboration on Advanced Neutron Sources. (to be published).

[Publications] H.Noda: "Pulse Shape Measurement of KENS Thermal Neutron Source in the eV Region by N-RAS"ICANS-XV : Proceedings of the 15^<th> Meeting of the International Collaboration on Advanced Neutron Sources. (to be published).

[Publications] Gary J.Russell: "Neutron Beam Line Shield Design for the Protein Crystallography Instrument"ICANS-XV : Proceedings of the 15^<th> Meeting of the International Collaboration on Advanced Neutron Sources. (to be published).

[Publications] Gary J.Russell: "Overview of Spallation Neutron Source Physics"the Proceedings of the Workshop on Fundamental Physics with Pulsed Neutron Beams. (2000)

[Publications] P.D.Ferguson: "Re-analysis of the Belyakov-Bodin Energy Deposition Experiment Using MCNPX"the proceedings of AccApp 2000. (to be published) .

[Publications] K.Corzine: "MCNPX Benchmarks of In- and Out-of-Beam Energy Deposition for 800-Me V Protons"the proceedings of AccApp 2000. (to be published).

[Publications] R.S.Lillard: "The Effects of High Energy Proton Radiation on the Corrosion of Materials"ASTM STP 1405.

[Publications] Gary J.Russell: "The Lujan Center : A Pulsed Spallation Neutron Source at Los Alamos"the Proceedings of ICONE-8. ICONE-8611. 1-12 (2000)

鬼柳善明北海道大学, 大学院・工学研究科, 教授 (80002202)