STUDIES OF VIBRATION-ROTATION ENERGY EXCHANGE USING HYDROGEN AND ITS ISOTOPES.

Experiments have been made on the systems CO//2 and COS with the following gases; normal-H//2; pH//2; nD//2; oD//2 and HD. Experiments were performed behind incident shock waves covering the temperature range 350 to 1000 K. The different efficiencies of the spin isomers showed that V-R processes are important, but V-T processes cannot be neglected. Calculations of V-R probabilities were made on the basis of the model developed by Sharma. For the case of CO//2 the calculations were quite successful in accounting for the differences in the efficiencies of the spin isomers. However neither the absolute values of the probabilities or their temperature coefficients could be accounted for completely in this way. For COS the picture is qualitatively similar, but the absolute values of the calculated probabilities are at least a factor of 10 too small and not all of the observed spin isomer effects can be accounted for using this model of V-R energy exchange.