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Intensities and Spectrum of Cosmic Rays in the past of 25000 years

Research Project

Project/Area Number 14540240
Research Category

Grant-in-Aid for Scientific Research (C)

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

Principal Investigator

SAKURAI Hirohisa  Yamagata University, Department of Physics, Professor, 理学部, 教授 (60150265)

Co-Investigator(Kenkyū-buntansha) MATSUZAKI H.  Tokyo University, Research Center for Nuclear Science and Technology, Associate Professor, 原子力総合センター, 助教授 (60313194)
TOKANAI F.  Yamagata University, Department of Physics, Assistant Professor, 理学部, 助手 (80323161)
GUNJI S.  Yamagata University, Department of Physics, Associate Professor, 理学部, 助教授 (70241685)
Project Period (FY) 2002 – 2003
Project Status Completed (Fiscal Year 2003)
Budget Amount *help
¥3,600,000 (Direct Cost: ¥3,600,000)
Fiscal Year 2003: ¥1,200,000 (Direct Cost: ¥1,200,000)
Fiscal Year 2002: ¥2,400,000 (Direct Cost: ¥2,400,000)
KeywordsCosmic Rays / Radiocarbon / Dating / AMS / Multi-cathode / LSC / 25000 years ago / step change / 宇宙線 / 極低レベル液体シンチレーション測定 / AMS測定 / 3.4%ステップ的変化
Research Abstract

We have measured the ^<14>C concentrations in single-year tree rings of old wood, using a multicathode by accelerated mass spectrometry (AMS). The ^<14>C concentrations of ten single-year tree rings were measured at intervals of 10, in 100 tree rings. For each single-year tree ring sample, typically 80 measurements of the ^<14>C concentrations were carried out using multicathodes. The sample standard deviations indicated that there are other fluctuations of typically 1.5% in addition to the fluctuation of the Poisson counting statistics that is typically 3% for each measurement. The average radiocarbon date of the tree rings was 22,130±306 BP for all 624 data measured by the multicathodes for the single-year tree ring samples. From the calibration data of Lake Suigetsu, the calendar dates of these one hundred tree rings were located between cal 25,400 yr BP and cal 26,150 yr BP. The radiocarbon dates changes between 21,979 Bp and 22,272 BP with error of approximately 50 BP, corresponding to the precision of approximately 0.5%. There was a step with a change of approximately 144 BP for each ten years in the time profile.

Report

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

    (9 results)

All Other

All Publications (9 results)

  • [Publications] H.Sakurai, et al.: "Characteristics of high-purity teflon vial of 14C measurement in old tree rings"Nucl.Instr.and Meth.in Physics Research A. 505. 454-457 (2004)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2003 Final Research Report Summary
  • [Publications] H.Sakurai, et al.: "AMS measurement of C-14 concentration in a single-year ring of a 2500-year-old tree"Mucl.Instr.and Meth.B. 2004.

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2003 Final Research Report Summary
  • [Publications] T.Gandou, H.Sakurai, et al.: "C-14 Concentrations of Single-Year Tree Rings From About 22,000 Years Ago Obtained Using a Highly Accurate Measuring Method"Radiocarbon. 46. (2004)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2003 Final Research Report Summary
  • [Publications] H.Sakurai, et al.: "Characteristics of high-purity teflon vial of 14C measurement in old tree rings"Nucl.Instr. and Meth.In Physics Research A. 505. 454-457 (2004)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2003 Final Research Report Summary
  • [Publications] H.Sakurai, et al.: "AMS measurement of C-14 Concentration in single-year ring of a 2500-year-old"Nucl.Instr. and Meth.. B. (2004)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2003 Final Research Report Summary
  • [Publications] T.Gandou, H.Sakurai, et al.: "C-14 Concentration of Single Year Tree Rings From About 22,000 Years Ago Obtained Using a Highly Accurate Measuring Method"Radiocarbon. 46. (2004)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2003 Final Research Report Summary
  • [Publications] H.Sakurai, et al.: "Characteristics of high-purity teflon vial of 14C measurement in old tree rings"Nucl.Instr.and Meth.in Physics Research A. 505. 454-457 (2003)

    • Related Report
      2003 Annual Research Report
  • [Publications] H.Sakurai, et al.: "AMS measurement of C-14 concentration in a single-year ring of a 2500-year-old tree"Mucl.Instr.and Meth.B. (2004)

    • Related Report
      2003 Annual Research Report
  • [Publications] H.Sakurai: "Characteristics of high-purity teflon vial of 14C measurement in old tree rings"Nucl. Instr. and Meth. in Physics Research A. 500号. 454-457 (2003)

    • Related Report
      2002 Annual Research Report

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

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