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Laser Spectroscopy on Earth Warm-up and Ozone Layer Destruction by SF_6 Gas

激光光谱研究地球变暖和SF_6气体对臭氧层的破坏

基本信息

批准号：
14550046
负责人：
KITAZIMA Iwao
金额：
$ 2.37万
依托单位：
University of Fukui
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2002
资助国家：
日本
起止时间：
2002 至 2003
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-14550046/
关键词：
SF_6 gas Multiple infrared photon absorption Hot-house effect Decomposed products Ozone destruction 9.6μm absorption spectrum C0_2 laser Photo-acoustic spectroscopy 赤外多光子励起紫外線吸収放電生成物オゾン準連続状態

项目摘要

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.

利用脉冲CO2激光器研究了SF6气体引起的两个环境问题；(A)温室效应对地球的影响和(B)臭氧层的破坏，尽管后者与氟里昂气体的破坏完全不同。(A)υ_3模的SF_6是CO_2激光器10.6μm分支的可饱和吸收体，它将吸收许多具有多个振动模式和准连续的红外光子。泵浦-探测法的红外双共振测量表明，从能量库准连续谱到宏态的弛豫时间很长，为500μS，而υ_6模的最低激发态为500 GbE。这可能是SF_6温室效应的原因。(B)用9.6μm分支的光声方法观察到了O_2放电产生的独特的臭氧光谱。在O_2放电中加入氟里昂气体R-22，大大减小了光谱中P和R分支之间的山谷深度。这意味着放电过程中臭氧的产生被氟里昂的游离氯阻止了。在我们的实验中，结果发现，在放电中加入SF_6也降低了氟里昂的光谱深度和光谱深度。因此，部分分解产物可能与游离氯一样，作为臭氧破坏剂的催化剂。