Vibrational energy relaxation in liquid N2CO mixtures

The vibrational energy relaxation rates of the liquid nitrogenCO system have been measured by optically pumping the collision-induced fundamental vibrational absorption band of liquid N₂ with the output of an HBr TEA laser. A radiatively dominated value of 56 ± 10 s is found for the intrinsic nitrogen relaxation time. The CO contribution to the decay rate is explained on the basis of a simple kinetic model and found also to be radiatively dominated at low CO concentrations. The importance of radiative trapping and energy transport in evaluating the lifetimes is demonstrated.