HYDROGEN AND HELIUM PRESSURE BROADENING OF H2S BETWEEN 2 AND 600 K

The hydrogen (H-2) and helium (He) pressure-broadening cross sections of the 1(10) <-- 1(01) transition of HS have been measured between 2 a nd 600 K. This more than two decade range in temperature makes possibl e the consideration of these collisions as a spectroscopic process in which the translational energy plays the role of the spectroscopic var iable. Although in the semiclassical region the pressure broadening du e to Hz and He is similar, at low temperature large qualitative differ ences occur, resulting in almost an order of magnitude larger cross se ction for collisions with Hz below 10 K. (C) 1994 Academic Press, Inc.