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

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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.