| Project/Area Number |
08454162
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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 |
地球化学
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| Research Institution | Univ.of Tokyo |
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Principal Investigator |
SUGIURA Naoji Univ.of Tokyo, Graduate School of Science, Professor, 大学院理学系研究科, 教授 (80196716)
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| Project Period (FY) |
1996 – 1997
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| Project Status |
Completed (Fiscal Year 1997)
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| Budget Amount *help |
¥3,200,000 (Direct Cost: ¥3,200,000)
Fiscal Year 1997: ¥1,500,000 (Direct Cost: ¥1,500,000)
Fiscal Year 1996: ¥1,700,000 (Direct Cost: ¥1,700,000)
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| Keywords | light elements / Botope / secondary ion mass spectrometry / nitrogen / carbon / hydrogen / 窒素 / 同位体比 / 感度 / 鉄隕石 |
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| Research Abstract |
The purpose of this project was to establish techniques for measuring light element abundances and isotopic ratios by SIMS.
1) Nitrogen measurements.
The method for measuring nitrogen abundances and isotopic ratios in metallic samples was established. As the nitrogen measurement is strongly affected by contamination, the detection limit is about 100 ppm. Isotopic composition of nitrogen can be measured with a precision of several permil at a nitrogen concentration of several hundreds of ppm.
2) Carbon measurements.
The method for measuring carbon abundances and isotopic ratios was established. The detection limit is several tens of ppm. At this concentration, the isotopic ratios can be determined with a precision of several permil. Such a measurement takes about 10 minutes.
3) Hydrogen measurements.
The detection limit of hydrogen has not been established yet. But at a concentration of 0.5 wt.% (e.g. biotite) the hydrogen signal is large enough of both abundance and isotopic measurements. At the moment.the precision of isotopic measurements is about 5%, which seems to be mainly due to not-well-controlled instrumental mass fractionation.
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