1996 Fiscal Year Final Research Report Summary
DEVELOPMENT OF DETECTION METHOD FOR MEASURING AMBIENT NO CONCENTRATION USING HIGH SENSITIVE LASER SPECTROSCOPIC TECHNIQUE
| Project/Area Number |
07454147
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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 | RESEACH CENTER FOR ADVANCED SCIENCE AND TECHNOLOGY,THE UNIVERSITY OF TOKYO |
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Principal Investigator |
KAJII Yoshizumi THE UNIVERSITY OF TOKYO RESEARCH CENTER FOR ADVANCED SCIENCE AND TECHNOLOGY,, 先端科学技術研究センター, 助教授 (40211156)
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| Co-Investigator(Kenkyū-buntansha) |
HIROKAWA Jun THE UNIVERSITY OF TOKYO RESEARCH CENTER FOR ADVANCED SCIENCE AND TECHNOLOGY,, 先端科学技術研究センター, 助手 (20262115)
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| Project Period (FY) |
1995 – 1996
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| Keywords | SUPER SONIC FREE JET / RETPI / UV-PULSE LASER / ROTATIONAL TEMPERATURE / INTERFERENCE OF NO_2 / COUNTING TECHNIOUE / LIMIT OF DETECTION |
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| Research Abstract |
we designed and constructed vacuum chamber and vacuum system for measuring ambient NO concentration. The laser system of tunable dye laser pumped by 3rd harmonic of pulsed nd : YAG laser was constructed. The out-put of dye laser was doubled to excite NO molecule into single ro-vibronic level. The analysis of rotationnal temperature was done to determine rotational temperature to be 25 K under X/D of 70. we reconfirmed resonance enhanced two photon ionization (RETPI) process rom the laser power dependence experiment showing index of 1.75. we employed ion counting system for detection of ion signals to increase S/N ratio. we found almost of two order of magnitude improvement of sensitivity by replacement of detection system from analog-to-digital operation to ion counting operation. we confirmed linear response of ion signal with NO concentration up to 200 ppb. In the chemical. interference of NO_2, the sensitivity of NO_2 is ca.2% compared to that of NO.This shows the improvement of selectivity by the cooling process. The limit of detection was estimated to be 16 pptv with an integration time of 1 min.
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