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Panity and Time Reversal Test in Very Slow Neutron Reactions

Research Project

Project/Area Number 09044075
Research Category

Grant-in-Aid for international Scientific Research

Allocation TypeSingle-year Grants
SectionJoint Research .
Research Field 素粒子・核・宇宙線
Research InstitutionFukui University of Technology (1998)
Kyoto University (1997)

Principal Investigator

MASAIKE Akira  Fukui Univ.of Technology, Faculty of Engineering, Professor, 工学部, 教授 (40022587)

Co-Investigator(Kenkyū-buntansha) PENITILA S.  Los Alamos Nat' Lab., Researcher, 研究員
ROBERSON R.  Duke Univ., Physics Department, Professor, 物理学部, 教授
BOWMAN D.  Los Alamos Nat' Lab., Senior Physicist, 主任研究員
SHIMIZU Hirohiko  RIKEN,Researcher, 研究員 (50249900)
FUNAHASHI Haruhiko  Kyoto Univ., Graduate School of Science, Research Associate, 理学研究科, 助手 (00283581)
D Bowman  ロスアラモス国立研究所, 主任研究員
酒井 健二  東京工業大学, 理学部, 助手 (40272661)
旭 耕一郎  東京工業大学, 理学部, 助教授 (80114354)
Project Period (FY) 1997 – 1998
Project Status Completed (Fiscal Year 1998)
Budget Amount *help
¥6,500,000 (Direct Cost: ¥6,500,000)
Fiscal Year 1998: ¥2,800,000 (Direct Cost: ¥2,800,000)
Fiscal Year 1997: ¥3,700,000 (Direct Cost: ¥3,700,000)
Keywordsparity / time reversal / helicity asymmetry / slow neutron / spin rotation / proton polarization / p-wave resonance / La polarization / 偏極陽子 / P波共鳴 / ナフタリン / ペンタセン / 共鳴呼吸反応 / 偏極中性子 / ヘリウム3偏極 / スピン回転 / パリティ非保存 / スピンアナライザー / オプティカル・ポンピング
Research Abstract

Polarized slow neutron reactions on nuclei in the resonance region are useful to investigate parity nonconservation (PNC) effect in nuclei, since large enhancement of PNC effect has been found in neutron absorptions on p-wave resonances. In order to study the origin of such large enhancement of the PNC effect, the longitudinal asymmetries in the neutron reactions have been measured for the targets of U, Th, Pd, I, In, Ag, Sb and Cs by means of a neutron transmission method and a gamma-ray detection method in the energy region of 1 eV to 350 eV at LANSCE.The experiment shows that the large enhancement is not the phenomena only for few resonances but is a prevalent fuature of p-wave resonances. Based on the statistical view of the compound nucleus, the weak spreading width GAMMAw has been determined to be the order of 10^<-7> eV in the wide range of mass number. The result can be explained by the s-p mixing model for the enhancement of PNC.
The parity nonconserving spin rotation in neutron transmission on a La target has also been measured. The result on the p-wave resonance is found to be consistent with the results of helicity asymmetries.
As a tool to study-time-reversal violation in neutron absorption reaction, the dynamic polarization of La nuclei in LaAlO_3 has been carried out successfully in a dilution refrigerator
On the other hand the proton in naphthalene doped with pentacene has been polarized using a later beam at 770K It will be useful to make polarized neutron beams for symmetry measurements.

Report

(3 results)
  • 1998 Annual Research Report   Final Research Report Summary
  • 1997 Annual Research Report
  • Research Products

    (19 results)

All Other

All Publications (19 results)

  • [Publications] 飯沼昌隆 他: "レーザ光による陽子スピンの偏極" パリティ. 12-12. 43-47 (1997)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1998 Final Research Report Summary
  • [Publications] Y.Matsuda: "Study of Parity Violation in Neutron Resonance Reaction in Nuclei" Memories of the Faculty of Science, Kyoto University, (Series of Physics, Astrophysics, Geophysics and Chemistry). 41-1. (1998)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1998 Final Research Report Summary
  • [Publications] B.E.Crawford et al.: "Nuetron resonance spectroscopy of ^<106>Pd and ^<106>Pd from 20 to 2000 eV" Phys.Rev.C. 58. 729-738 (1998)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1998 Final Research Report Summary
  • [Publications] B.E.Crawford et al.: "Parity nonconservation in neutron resonances in ^<238>U" Phys.Rev.C. 58. 1225-1235 (1998)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1998 Final Research Report Summary
  • [Publications] S.L.Stephenson et al.: "Parity nonconservation in neutron resonances in ^<232>Th" Phys.Rev.C. 58. 1236-1246 (1998)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1998 Final Research Report Summary
  • [Publications] Y.Matsuda: "Study of Parity Violation in Neutron Resonance Reaction in Nuclei" Memories of the Faculty of Science, Kyoto University, (Series of Physics, Astrophysics, Geophysics and Chemistry) Vol 41, No.1, (1998) Ph.D.thesis, Kyoto University. (1998)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1998 Final Research Report Summary
  • [Publications] B.E.Crawford et al: "Nuetron resonance spectroscopy of ^<106>Pd and ^<108>Pd from 20 to 2000 eV" Phys.Rev.C. 58. 729-738 (1998)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1998 Final Research Report Summary
  • [Publications] B.E.Crawford et al.: "Parity nonconservation in neutron resonances in ^<238>U" Phys.Rev.C. 58. 1225-1235 (1998)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1998 Final Research Report Summary
  • [Publications] S.L.Stephenson et al.: "Parity nonconservation in neutron resonances in ^<232>Th" Phys.Rev.C. 58. 1236-1246 (1998)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1998 Final Research Report Summary
  • [Publications] 飯沼昌隆 他: "レーザ光による陽子スピンの偏極" パリティ. 12-12. 43-47 (1997)

    • Related Report
      1998 Annual Research Report
  • [Publications] Y.Matsuda: "Study of Parity Violation in Neutron Resonance Reaction in Nuclei" Memories of the Faculty of Science,Kyoto University,(Series of Physics,Astrophysics,Geophysics and Chemistry). 41-1. (1998)

    • Related Report
      1998 Annual Research Report
  • [Publications] B.E.Crawford et al.: "Nuetron resonance spectroscopy of^<106>Pd and ^<106>Pd from 20 to 2000eV" Phys・Rev・C. 58. 729-738 (1998)

    • Related Report
      1998 Annual Research Report
  • [Publications] B.E.Crawford et al.: "Parity nonconservation in neutron resonances in ^<238>U" Phys・Rev・C. 58. 1225-1235 (1998)

    • Related Report
      1998 Annual Research Report
  • [Publications] S.L.Stephenson et al.: "Parity nonconservation in neutron resonances in^<232>Th" Phys・Rev・C. 58. 1236-1246 (1998)

    • Related Report
      1998 Annual Research Report
  • [Publications] K.Sakai, et al.: "Observation of parity-violating neutron spin rotation in the n-^<139>La p-wave resonance" Phys.Lett.B. 391. 11-14 (1997)

    • Related Report
      1997 Annual Research Report
  • [Publications] L.Y.Lowie, et al.: "Neutron resonance spectroscopy of ^<107>Ag and ^<109>Ag" Phys.Rev.C. 56. 90-97 (1997)

    • Related Report
      1997 Annual Research Report
  • [Publications] Yen Yi-Fen, et al.: "Determination of the gamma-ray background in a pulsed epithermal neutron beam" Nucl.Inst.Meth.A. 397. 365-370 (1997)

    • Related Report
      1997 Annual Research Report
  • [Publications] A.N.Chernikov, et al.: "Energy and orientation dependence of neutron depolarization in a large single crystal of ferromagnetic holmium" J.Appl.Phys.(USA). 81. 1358-1361 (1997)

    • Related Report
      1997 Annual Research Report
  • [Publications] P.R.Huffman, et al.: "Test of parity-conserving time-reversal invariance using polarized neutrons and nuclear spin aligned holmium" Phys.Rev.C. 55. 2684-2696 (1997)

    • Related Report
      1997 Annual Research Report

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Published: 1997-04-01   Modified: 2017-10-11  

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