Detailed characteristics of a pulsed H2+F2 laser. 2: Theory

An attempt is made to predict the small signal gain, total pulse energy, and time-resolved spectroscopy produced by a flash photolytically initiated, H2 + F2 chain reaction laser. Computer modeling results using four chemical kinetic mechanisms are compared to the experimental data from a previous study. These comparisons show that a model assuming vibrational-to-translational energy transfer as the dominant HF deactivation channel more closely predicts gain and spectroscopic durations, initiation, peak and termination times, peak gain magnitudes, and total pulse energies than a similar model assuming vibrational-to-rotational energy transfer as the dominant deactivation channel. This is contrary to current understanding of HF kinetic mechanisms. Model results also indicate that rotational relaxation is fast compared to other deactivation processes, but slow compared to stimulated emission. The model gives an estimated lower bound for the experimental(F)/(F2) ratio of 0.0025 percent.