| Project/Area Number |
09440196
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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 |
Physical chemistry
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| Research Institution | Tokyo Institute of Technology |
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Principal Investigator |
SHIBUYA Kazuhiko Tokyo Institute of Technology, Graduate School of Science and Engineering, Associate Professor (30126320)
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| Co-Investigator(Kenkyū-buntansha) |
KAWAI Akio Tokyo Institute of Technology, Graduate School of Science and Engineering, Associate (50262259)
TSUJI Kazuhide Tokyo Institute of Technology, Graduate School of Science and Engineering, Associate (40262258)
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| Project Period (FY) |
1997 – 1998
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| Project Status |
Completed (Fiscal Year 1998)
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| Budget Amount *help |
¥14,200,000 (Direct Cost: ¥14,200,000)
Fiscal Year 1998: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 1997: ¥13,500,000 (Direct Cost: ¥13,500,000)
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| Keywords | CRD Speolrescopy / OH / O_3 interference / trace. gao / concentration / atmospherie model / リングダウンタイム / レーザー分光 / ラジカル / 濃度ラベル法 / キャビティーリングダウン / 大気化学 / NO_2 / NO_3 |
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| Research Abstract |
A cavity-ringdown spectroscopic apparatus has been built up. Though the spectral linewidth measured for OH was narrow, the ambient experimental conditions fulfill the Lambert-Beer conditions and therefore the linearity of the measurements. The detection limit was estimated as 1.5x10^9 molecules/cm^3 under the ambient pressure conditions.
This detection limit can be improved theoretically to 5x10^7 molecules/cm^3. This value is still less sensitive than the expected limit, possibly due to the instability of the cavity, which will be solved in future.
The reflectivity of mirrors, the length of the cavity, and noise mainly control the detection limit. The consideration was performed to improve the limit 1000 times, which realizes the field measurements of OH by the present detection method.
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