Vibration-to-Vibration Energy Transfer of CO₂(00⁰1) with N₂ and CO at Low Temperatures

Abstract

The 4.3μm fluorescence from CO₂(00⁰1) induced by the pulsed irradiation of the HBr laser line of P ₋₂ (6) transition has been measured in the CO₂–N₂ and CO₂–CO mixtures at 300∼150K. The analysis based on the mechanism including the inter- and intra-molecular vibration-to-vibration (V–V) energy transfers of CO₂(00⁰1) gives the rates for respective processes. The observed V–V rate between CO₂(00⁰1) and N₂ shows a negative temperature dependence, and agrees with a simple extrapolation of the data at higher temperatures as well as the calculation by the Sharma-Brau theory. Contrary to this, the intermolecular V–V rate between CO₂(00⁰1) and CO attains a minimum at a temperature around 300K. The intramolecular V–V rate could be determined only for the mixture of CO₂ and N₂; the temperature dependence of the rate was reduced at lower temperatures and this was a phenomenon common to the CO₂(00⁰1) deactivation in inert monoatomic gases.