TA9 - Time-dependent calculations of carbon monoxide laser kinetics

Abstract

We report here calculations of pulsed CO laser operation by revealing the time evolution of the CO vibrational distribution function in electrically pumped CO-N <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> -He mixtures. This is accomplished through a time-dependent solution of the coupled rate equations for the first 50 vibrational levels of CO considering V-V and V-T processes, spontaneous and stimulated emission, electron impact excitation, and deexcitation as well as kinetic heating of the lasing medium. The electron excitation rates as a function of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">E/N</tex> are obtained from calculations of the steady-state electron distribution function in the appropriate gas mixtures. In addition to following the time dependence of pulsed operation, CW calculations have been performed for the purpose of comparison with the results of other investigators. Comparisons between the predicted time of appearance of lasing lines and experimental data is quite good for both the free-running and single-line modes of operation.