| Project/Area Number |
13440181
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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 | OKAYAMA UNIVERSITY |
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Principal Investigator |
KAWAGUCHI Kentaro OKAYAMA UNIVERSITY, Faculty of Science, Chemistry, Prof., 理学部, 教授 (40158861)
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| Co-Investigator(Kenkyū-buntansha) |
KUBOZONO Yoshihiro OKAYAMA UNIVERSITY, Faculty of science, Chemistry, Associate Prof., 理学部, 助教授 (80221935)
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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 |
¥12,500,000 (Direct Cost: ¥12,500,000)
Fiscal Year 2003: ¥2,200,000 (Direct Cost: ¥2,200,000)
Fiscal Year 2002: ¥4,000,000 (Direct Cost: ¥4,000,000)
Fiscal Year 2001: ¥6,300,000 (Direct Cost: ¥6,300,000)
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| Keywords | Infrared emission / infrared array detector / laser spectroscopy / infrared diode laser / Laser excitation / 大気中NNOの同位体存在量 / 赤外線吸収スペクトル |
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| Research Abstract |
In the present study we had an aim to construct a spectroscopic system to detect infrared emission with high sensitivity. So far infrared emission has been observed mainly by Fourier transform spectroscopic method. However, the method is limited to species such as diatomic molecules mainly. Since the probability of emission in the infrared region is not high, we considered laser excitation spectroscopy to observe induced emission, where an infrared laser is used to saturate a vibration-rotational transitions of molecules.
One of advantages of the present study is to rise an infrared array detector to observation of weak emission spectra. An infrared array detector with InSb X56 x 256 elements was installed in a dewar of 35 K. Data from the detector were read out by using COGITO-3 system and transferred to a work station and analyzed by an IRAF software. The detection system was coupled to a grating spectrometer to observe emission spectrum.
For excitation source, an infrared diode laser system was set up by using commercially available laser elements which operate under low temperature of 12-80 K. The system was applied to absorption spectroscopy by using multi-path cell to determine isotopic abundance ratios of the atmospheric N_2O molecule.
The output power of the diode laser was not enough for saturating vibration-rotation transitions, so a quantum cascade laser_(QC laser) is considered as the candidate of excitation source. We carried out a co-operative study with HAMAMATSU HOTONIKUSU to investigate the performance of the QC lasers. It was found that the output power was enough large (about 100 mW) for the present purpose and application to laser excitation spectroscopy has been carried out.
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