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Alpha-decay from the 3.5 eV isomer of 229Th

  • T. Mitsugashira
  • M. Hara
  • T. Ohtsuki
  • H. Yuki
  • K. Takamiya
  • Y. Kasamatsu
  • A. Shinohara
  • H. Kikunaga
  • T. Nakanishi
Article

Abstract

The alpha-decay of a low energy isomer of 229Th at about 3.5 eV was sought by producing it through the (g,n) reaction on a 230Th target. Thorium isotopes in the reaction products were isolated and purified by anion exchange chromatography in a concentrated nitric acid medium to remove lanthanides fission products. The thorium fraction was further purified by samarium fluoride coprecipitation and the precipitate was mounted as a source for a-spectroscopy. Decaying a-signals were observed in the energy region that was expected for 229mTh, i.e., between 4.83 and 5.08 MeV. The half-life of the decaying component was determined from repeated experiments to be 13.9±3 hours.

Keywords

Nitric Acid Thorium Anion Exchange Fission Product Exchange Chromatography 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Copyright information

© Kluwer Academic Publishers/Akadémiai Kiadó 2003

Authors and Affiliations

  • T. Mitsugashira
    • 1
  • M. Hara
    • 1
  • T. Ohtsuki
    • 2
  • H. Yuki
    • 3
  • K. Takamiya
    • 4
  • Y. Kasamatsu
    • 5
  • A. Shinohara
    • 5
  • H. Kikunaga
    • 6
  • T. Nakanishi
    • 6
  1. 1.The Oarai-branch, Institute for Materials ResearchTohoku UniversityNarita-machi, Oarai-machi, IbarakiJapan
  2. 2.Laboratory of Nuclear Science, Faculty of ScienceTohoku University Laboratory of Nuclear ScienceMikamine, SendaiJapan
  3. 3.Laboratory of Nuclear Science, Faculty of ScienceTohoku UniversityMikamine, SendaiJapan
  4. 4.Research Reactor InstituteKyoto UniversityKumatori, OsakaJapan
  5. 5.Graduate School of ScienceOsaka UniversityOsakaJapan
  6. 6.Graduate School of ScienceKanazawa UniversitKanazawaJapan

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