2003 Fiscal Year Final Research Report Summary
Laser Spectroscopy on Earth Warm-up and Ozone Layer Destruction by SF_6 Gas
| Project/Area Number |
14550046
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Applied physics, general
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| Research Institution | University of Fukui |
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Principal Investigator |
KITAZIMA Iwao University of Fukui, Department of Electrical and Electronic Engineering, professor, 工学部, 教授 (80020238)
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| Co-Investigator(Kenkyū-buntansha) |
NIKI Hideaki University of Fukui, Department of Electrical and Electronic Engineering, Associate professor, 助教授 (00135758)
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| Project Period (FY) |
2002 – 2003
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| Keywords | SF_6 gas / Multiple infrared photon absorption / Hot-house effect / Decomposed products / Ozone destruction / 9.6μm absorption spectrum / C0_2 laser / Photo-acoustic spectroscopy |
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| Research Abstract |
Two environmental problems induced by SF_6 gas were investigated by pulsed C0_2 lasers ; (a)hothouse effect on the earth and(b)ozone layer destruction, though the latter was not at all recognized in contrast with that by Freon gases.
(a)SF_6 of υ_3 mode, saturable absorber for the 10.6μm branch of C0_2 laser, will absorb many infrared photons, with many vibrational modes and quasi-continuum.Infrared double-resonance measurements of pump-probe method make it clear the relaxation time from the quasi-continuum of energy reservoir to the grand state is very long of 500μs, while the lowest excited level of υ_6 mode, as a bottle-neck is easily affected by thermal excitation.This explanatidn of Thermal Trapping may surely be the i~eason of hothouse effect of SF_6.
(b)The unique spectrum of ozone produced by 0_2 discharge was observed with the photo-acoustic method of the 9.6μm branch.The valley depth of the spectrum, between the P and R branches, was much decreased by adding Freon gas R-22 into 0_2 discharge.This means that ozone production during the discharge was prevented by free Cl of Freon.In our experiment, it was found that the addition of SF_6 into the discharge also reduced the spectral depth as well as that of Freon. So, some decomposed products may work as a catalyst of ozone destroyer as the same as free Cl.
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Research Products
(10 results)
