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Re-Os Cosmo chronometer

Research Project

Project/Area Number 14204025
Research Category

Grant-in-Aid for Scientific Research (A)

Allocation TypeSingle-year Grants
Section一般
Research Field 素粒子・核・宇宙線
Research InstitutionOsaka University

Principal Investigator

NAGAI Yasuki  Osaka Univ., Research Center for Nuclear Physics, Professor, 核物理研究センター, 教授 (80028240)

Co-Investigator(Kenkyū-buntansha) ITAHASHI Takahisa  Osaka Univ., Research Center for Nuclear Physics, Asoc.Prof., 核物理研究センター, 助教授 (20112071)
SHIMA Tatsushi  Osaka Univ., Research Center for Nuclear Physics, Res.Assist., 核物理研究センター, 助手 (10222035)
TAKAHISA Keiji  Osaka Univ., Research Center for Nuclear Physics, Res.Assist., 核物理研究センター, 助手 (30263338)
IGASHIRA Masayuki  Tokyo Inst.Tech., Research Lab.For Nucl.Reactors, Asso.Prof., 原子炉工学研究所, 助教授 (10114852)
大崎 敏郎  東京工業大学, 原子炉工学研究所, 助手 (80262327)
Project Period (FY) 2002 – 2004
Project Status Completed (Fiscal Year 2004)
Budget Amount *help
¥44,980,000 (Direct Cost: ¥34,600,000、Indirect Cost: ¥10,380,000)
Fiscal Year 2004: ¥4,680,000 (Direct Cost: ¥3,600,000、Indirect Cost: ¥1,080,000)
Fiscal Year 2003: ¥14,560,000 (Direct Cost: ¥11,200,000、Indirect Cost: ¥3,360,000)
Fiscal Year 2002: ¥25,740,000 (Direct Cost: ¥19,800,000、Indirect Cost: ¥5,940,000)
KeywordsCosmo chronology / Nuclear Cosmo Clock / rapid process / slow process / nucleosynthesis / neutron capture reaction / Re-Os pair / 中性子捕獲反応 / 弾性散乱 / 非弾性散乱 / 宇宙年令 / γプロセス / Sプロセス
Research Abstract

^<187>Re-^<187>Os pair is known as one of cosmochronometers, since ^<187>Re is produced by only r-process and its half life is quite long 42.3±1.3Gyr. ^<187>Os is produced by s-process of ^<186>Os. In addition, there is a problem originating from the excited state at 10 keV in ^<187>Os, which could be populated at stellar temperature, and therefore ^<187>Os is depleted by the (n,γ)process the through the state. In order to correct for the loss rate we measured both the (n,γ) cross sections and neutron inelastic cross sections of ^<186>Os, ^<187>Os and ^<189>Os using a newly developed experimental method. Pulsed neutrons were bombarded on enriched samples of ^<186>Os, ^<187>Os and ^<189>Os and ^<197>Au. The (n,γ)cross section of Os isotopes was measured using an anti-Compton NaI(Tl) spectrometers by detecting prompt gamma rays feeding from a neutron capture state of Os to low lying states. For the measurement of the ^<189>Os(n,n')^<189>Os reaction cross section we have developed a new detection system with use of four Li-glass detectors with a diameter of 50 mm and a thickness of 10 mm. Neutron energy scattered elastically and/or inelastically by ^<189>Os is determined by employing a TOF method. The discrimination between scattered neuron by ^<189>Os and gamma ray background can be made by their pulse heights. In order to obtain the inelastic scattering cross section of ^<189>Os accurately, it was crucial to prevent direct neutrons from the ^7Li(p,n) ^7Be reaction entering into the Li-glass detector. To find proper arrangement of these shield materials of borated polyethylene, cadmium and Boron, an extensive calculation has been made using a Monte Carlo Code. In addition, through many R & D works we have finally succeeded to construct a high sensitive measuring system of the inelastic scattering cross section of a nucleus. We succeeded to measure the ^<187>Os(n,n')^<187>Os cross section with high accuracy.

Report

(4 results)
  • 2004 Annual Research Report   Final Research Report Summary
  • 2003 Annual Research Report
  • 2002 Annual Research Report
  • Research Products

    (42 results)

All 2005 2004 2003 2002 Other

All Journal Article (31 results) Publications (11 results)

  • [Journal Article] 7Li(n,γ)8Li reaction and the S17 factor at Ec.m>500 keV2005

    • Author(s)
      Y.Nagai et al.
    • Journal Title

      Physical Review C71

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2004 Final Research Report Summary
  • [Journal Article] 62Ni(n,γ)63Ni reaction and overproduction of Ni isotopes2005

    • Author(s)
      A.Tomyo et al.
    • Journal Title

      Astrophysical Journal 623

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2004 Final Research Report Summary
  • [Journal Article] 7Li(n,γ)8Li reaction and the S17 factor at Ec.m.>500 keV2005

    • Author(s)
      Y.Nagai et al.
    • Journal Title

      Physical Review, C 71

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2004 Final Research Report Summary
  • [Journal Article] ADS network in Japan and in Asia2004

    • Author(s)
      Y.Nagai
    • Journal Title

      Proc.Tours symp.on nuclear phys. V

      Pages: 323-327

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2004 Final Research Report Summary
  • [Journal Article] Desighn of a compact 4π Ge spectrometer for the measurement of neutron capture cross sections of minor actinides2004

    • Author(s)
      M.Sugawara et al.
    • Journal Title

      J.of nuclear science and technology 41

      Pages: 1129-1137

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2004 Final Research Report Summary
  • [Journal Article] Target preparation of highly adhesive enriched 12C On Au substrates by a HIVIPP method2004

    • Author(s)
      I.Sugai et al.
    • Journal Title

      Nuclear Instruments and Methods, A 521

      Pages: 227-234

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2004 Final Research Report Summary
  • [Journal Article] 中性子が拓く宇宙核物理2004

    • Author(s)
      永井泰樹
    • Journal Title

      日本中性子科学会誌 14

      Pages: 71-73

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2004 Final Research Report Summary
  • [Journal Article] Design of a Compact 4π Ge Spectrometer for the Measurement of Neutron Capture Cross Sections of Minor Actinides2004

    • Author(s)
      M.Sugawara et al.
    • Journal Title

      J.Nuci.Science and Technology 41

      Pages: 1129-1129

    • Related Report
      2004 Annual Research Report
  • [Journal Article] Evaluation of Fast Neutron Induced Single Event Upset in a Static Random Access Memory and Simulation by Monte Carlo N-Particle Code2004

    • Author(s)
      Y.Arita et al.
    • Journal Title

      Japanese Journal of Applied Physics 43

    • Related Report
      2004 Annual Research Report
  • [Journal Article] Target preparation of highly adhesive enriched 12C on Au substrates by a HIVPP method2004

    • Author(s)
      I.Sugai et al.
    • Journal Title

      Nucl.Instr.And Methods A521

      Pages: 227-227

    • Related Report
      2004 Annual Research Report
  • [Journal Article] Photodisintegration cross section of 3He and 4He at low energies2003

    • Author(s)
      T.Shima et al.
    • Journal Title

      Nuclear Physics A718

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2004 Final Research Report Summary
  • [Journal Article] Measurement of the p(n,γ)d reaction cross section between 100 & 3502003

    • Author(s)
      A.Tomyo et al.
    • Journal Title

      Nuclear Physics A718

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2004 Final Research Report Summary
  • [Journal Article] Preparation for the 12C(α,γ)160 experiment using pulsed α-beam2003

    • Author(s)
      H.Makii et al.
    • Journal Title

      Nuclear Physics A718

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2004 Final Research Report Summary
  • [Journal Article] (n,γ) cross section measurement of 20,22Ne for nucleosynthesis2003

    • Author(s)
      A.Tomyo et al.
    • Journal Title

      Nuclear Physics A718

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2004 Final Research Report Summary
  • [Journal Article] Photodisintegration cross section of 3He and 4He at low energies2003

    • Author(s)
      T.Shima et al.
    • Journal Title

      Nuclear Physics, A 718

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2004 Final Research Report Summary
  • [Journal Article] Measurement of the p(n,γ)d reaction cross section between 100 & 3502003

    • Author(s)
      A.Tomyo et al.
    • Journal Title

      Nuclear Physics, A 718

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2004 Final Research Report Summary
  • [Journal Article] Preparation for the 12C(α,γ)16O experiment using pulsed α-beam2003

    • Author(s)
      H.Makii et al.
    • Journal Title

      Nuclear Physics, A 718

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2004 Final Research Report Summary
  • [Journal Article] (n,γ) cross section measurement of 20,22Ne for nucleosynthesis2003

    • Author(s)
      A.Tomyo et al.
    • Journal Title

      Nuclear Physics, A 718

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2004 Final Research Report Summary
  • [Journal Article] 84Kr(n,γ)85Kr reaction cross section measured By an NaI(Tl) spectrometer between 10 and 80 keV2003

    • Author(s)
      A.Tomyo et al.
    • Journal Title

      Nuclear Physics, A 718

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2004 Final Research Report Summary
  • [Journal Article] Direct measurement of the E1 and E2 cross sections of the 12C(α,γ)16O reaction at Ec.m.=1.3〜1.5 MeV2003

    • Author(s)
      T.Shima et al.
    • Journal Title

      Proc.of Int.Symp.on the origin of matter and evolution of galaxies

      Pages: 217-225

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2004 Final Research Report Summary
  • [Journal Article] Neutron experiment for the study of Re/Os cosmochronometer2003

    • Author(s)
      M.Segawa et al.
    • Journal Title

      Proc.of Int.Symp.on the origin of matter and evolution of galaxies

      Pages: 521-524

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2004 Final Research Report Summary
  • [Journal Article] Neutron experiment for Re/Os cosmochronometer2003

    • Author(s)
      M.Segawa
    • Journal Title

      Proc.JAERI Conf.

      Pages: 233-236

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2004 Final Research Report Summary
  • [Journal Article] The measurement of neutron capture cross section of 62Ni and nucleosynthesis of heavy elements2003

    • Author(s)
      Y.Temma et al.
    • Journal Title

      Proc.JAERI Conf.

      Pages: 237-240

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2004 Final Research Report Summary
  • [Journal Article] 中性子が拓く天体核物理2003

    • Author(s)
      永井泰樹
    • Journal Title

      J.Plasma fusion research 79

      Pages: 884-890

    • NAID

      10011370753

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2004 Final Research Report Summary
  • [Journal Article] Critical role of (n,γ) reaction of light nuclei in nuclear astrophysics2002

    • Author(s)
      Y.Nagai et al.
    • Journal Title

      Proc.of Eleventh.Int.Symp.On Capture Gamma-ray Spectroscopy and related topics

      Pages: 305-310

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2004 Final Research Report Summary
  • [Journal Article] Measurement of the 18O(n,γ)19O reaction cross sections by prompt γ-ray detection methods at thermal and keV neutrons2002

    • Author(s)
      T.Ohsaki et al.
    • Journal Title

      Proc.of Eleventh.Int.Symp.On Capture Gamma-ray Spectroscopy and related topics

      Pages: 364-370

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2004 Final Research Report Summary
  • [Journal Article] Measurement system of the γ-ray angular distributions of the 12C(α,γ)16O reaction

    • Author(s)
      H.Makii et al.
    • Journal Title

      Nuclear Instruments & Methods (in press)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2004 Final Research Report Summary
  • [Journal Article] Measurement of the keV neutron capture cross section of 62Ni

    • Author(s)
      Y.Nagai et al.
    • Journal Title

      Nuclear Physics (in press)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2004 Final Research Report Summary
  • [Journal Article] Measurement of the 12C(α,γ)16O reaction cross Section using pulsed α beams

    • Author(s)
      H.Makii et al.
    • Journal Title

      Nuclear Physics (in press)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2004 Final Research Report Summary
  • [Journal Article] Neutron experiment for the study of Re/Os cosmochrnometer

    • Author(s)
      M.Segawa et al.
    • Journal Title

      Nuclear Physics (in press)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2004 Final Research Report Summary
  • [Journal Article] keV neutron capture reaction of 62Ni And nucleosynthesis of heavy elements

    • Author(s)
      Y.Temma et al.
    • Journal Title

      Proc.Of JAERI conf. (in press)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2004 Final Research Report Summary
  • [Publications] Y.Nagai: "ADS Network in Japan and in Asia"Proc.Tours 2003 Symp.Nuclear Physics. V. (2004)

    • Related Report
      2003 Annual Research Report
  • [Publications] 永井 泰樹: "中性子が拓く天体核物理"プラズマ・核融合学会誌. 79. 884-890 (2003)

    • Related Report
      2003 Annual Research Report
  • [Publications] 永井 泰樹: "中性子が拓く宇宙核物理研究"波紋(日本中性子科学会). 14. 71-73 (2004)

    • Related Report
      2003 Annual Research Report
  • [Publications] T.Shima et al.: "Photodisintegration cross sections of ^3He and ^4He at low energies"Proc.Seventh Int.Conf.Nuclei in the Cosmos. 23-28 (2003)

    • Related Report
      2003 Annual Research Report
  • [Publications] A.Tomyo et al.: "Neutron capture cross section measurement of ^<20.22>Ne for stellar nucleo synthesis"Proc.Seventh Int.Conf.Nuclei in the Cosmos. 527-529 (2003)

    • Related Report
      2003 Annual Research Report
  • [Publications] 永井 泰樹: "プラズマ・核融合学会誌"中性子が拓く天体核物理. 6 (2003)

    • Related Report
      2003 Annual Research Report
  • [Publications] Y.Nagai et al.: "Neutron Reactions of Light Nuclei from Astrophysics and Nuclear Physics Interest"Astrophysics, Symmetries, and Applied Physics at Spallation Neutron Sources. 52-57 (2002)

    • Related Report
      2002 Annual Research Report
  • [Publications] Y.Nagai et al.: "CRITICAL ROLE OF (n,γ) REACTION OF LIGHT NUCLEI IN NUCLEAR ASTROPHYSICS"Proceedings of Eleventh international Symposium on Capture γ-Ray Spectroscopy and Related Topics (CGS 11). (2002)

    • Related Report
      2002 Annual Research Report
  • [Publications] A.Tomyo et al.: "84Kr (n, γ) 85Kr reaction cross section measured by an NaI(TL) spectrometer between 10 and 80 keV"Proceedings of 7^<th> Int. Sym. on Nuclei in the Cosmos. (2002)

    • Related Report
      2002 Annual Research Report
  • [Publications] A.Tomyo et al.: "Neutron capture cross section measurement of 20,22Ne for stellar nucleosynthesis"Proceedings of 7^<th> Int. Sym. on Nuclei in the Cosmos. (2002)

    • Related Report
      2002 Annual Research Report
  • [Publications] Y.Nagai et al.: "Measurement of the p(n, γ)d reaction cross section between En = 100 and 35OkeV"Proceedings of 7^<th> Int. Sym. on Nuclei in the Cosmos. (2002)

    • Related Report
      2002 Annual Research Report

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Published: 2002-04-01   Modified: 2016-04-21  

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