Vibrational relaxation of CF4 and CH4 and energy transfer between these gases and CO

Abstract

Measurements have been made of the rates of vibrational relaxation of CF₄ and of CH₄ in the temperature range 400–700 K using a shock tube.

Below 600 K the equilibrium population of CO in the (v= 1) state is very small and it is possible to measure the rates of the (VT) excitation of CF₄ and of CH₄ by CO. Rate constants have been determined for these processes in the temperature range 400–450 K.

Above temperatures of 750 K it is possible to measure the rates for the vibrational excitation of CO by vibrationally excited CF₄, or by vibrationally excited CH₄. Data are given for these processes in the temperature range 750–1500 K and comparisons are made with laser fluorescence data at lower temperatures on the vibrational deactivation of CO by CF₄ and by CH₄.