| Project/Area Number |
13480147
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Nuclear engineering
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| Research Institution | Osaka University |
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Principal Investigator |
IKEYA Motoji OSAKA UNIVERSITY, Graduate School of Science, Professor (20023161)
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| Co-Investigator(Kenkyū-buntansha) |
YAMANAKA Chihiro 大阪大学, Graduate School of Science, Associate Professor (10230509)
KATSURA Makoto (HIRAI, Makoto) 大阪大学, Graduate School of Science, Research Associate (70304003)
TANI Atsushi 大阪大学, Graduate School of Science, Research Associate (10335333)
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| Project Period (FY) |
2001 – 2003
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| Project Status |
Completed (Fiscal Year 2003)
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| Budget Amount *help |
¥9,500,000 (Direct Cost: ¥9,500,000)
Fiscal Year 2003: ¥1,900,000 (Direct Cost: ¥1,900,000)
Fiscal Year 2002: ¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 2001: ¥5,600,000 (Direct Cost: ¥5,600,000)
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| Keywords | ESR / dosimetry / tissue equivalent / organic acid / Li / thermoluminescence / dating / radiation / ラジカル / 放射線量 / 線幅 / ビタミンC / MgSO_4 / 高感度 / MgSo_4 / 線量計測 / JCO事故 / 歯 / 人類学 / 廃棄物処理 / 照射食品の評価 |
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| Research Abstract |
A high sensitive and tissue equivalent radiation dosimeter material for electron spin resonance (ESR) dosimeter has been developed using lithium-organic acid compounds. Several Li- and Mg-organic acid compounds were irradiated by gamma rays from the source of 60Co at room temperature and measured with ESR to analyze the signals of radiation-induced radicals and to obtain their formation efficiency, G-value (Radical pairs per100eV). ESR spectroscopy utilizing magnetic field modulation at 100kHz give a derivative line of the microwave absorption. Hence, the sharper the line width, higher signal to noise (S/N) ratio.
Li- and Mg-oxalate and other several organic compounds such as Li-lactate, Mg-lactate, Li-trifluoo-methane-sulfonate, Li-oxalate, Mg-oxalate. Among these compounds, Li-oxalate, LiOOC-COOLi a candidate since they do not contain any hydrogen atom which broaden the ESR signal of radicals by the hyperfine and super-hyperfine interactions.
Other materials such as LiZrO_3 coesite and
… More
styshovite (SiO_2) and natural minerals have been investigated from the viewpoint of ESR dosimetry and radiation effects. Publications of the works on some natural minerals and Antarctic ice as well as ice in a laboratory were added in the list of publication to show our research activities.
International Symposium on ESR Dosimetry and Dating was held at Osaka University (2001-ESRDD-Osaka) to summarize the works in these fields and to give a new prospect at the start of 21st century. Proceedings of the paper was edited and published in Advances on ESR Applications. Finally a book "New Applications of Electron Spin Resonance-Dating, Dosimetry and Microscopy" was updated, partially revised and published by the World Scientific Publishing Co. in Singapore. The new prospects and early works in 21st century were reviewed in the first chapter of the book Paramagnetic Resonance: Specialist Periodical Reports Vol.19 published by the Royal Society of Chemistry at the end of 2004.
The principal investigator on his retirement would like to thank the research reviewers and all persons concerned for supporting this work and the field of ESR dosimetry and dating for these three decades. I am happy to have established a field of ESR dating and dosimetry. Less
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