Simplified analytical model for calculation of population inversion in channels of CW gasdynamic lasers operating at various transitions among levels pertaining to coupled upsilon 1 and upsilon 2 modes of CO2

A theoretical model of population inversion formation by rapid expansion of a heated mixture of CO2 and diluent is described. Admissible transitions between CO2 levels comprised in coupled upsilon 1 and 2 modes are considered, without assumptions regarding the form of the vibrational energy distribution function. The vibrational energy exchange and relaxation processes, and induced changes in population of 30 CO2 levels, are described, using SSH theory to determine the rate costants. An example concerning the expansion of a CO2/Ar mixture in a nozzle indicates that a large number of CO2 lasers can be thermally excited and pumped by a gasdynamic technique.