Influence of SF6 on the energy characteristics of an H2–F2 chemical laser

A model of a hydrogen fluoride laser taking into account the finite rate of rotational relaxation is used to study the influence of the addition of SF₆ to the mixture on the energy characteristics of a pulsed H₂–F₂ chemical laser. A comparison between the results of the calculations and the experimental data suggests that an increase in the laser energy with increasing SF₆ concentration in the active mixture is largely due to a rise in the rate of rotational relaxation of the HF molecules. It is shown that a drop in the specific laser output energy at very high SF₆ concentrations is not only due to an increase in the rate of vibrational–rotational relaxation, but also to the influence of the resonator threshold on the laser energy characteristics as a result of the appreciable broadening of the HF vibrational–rotational lines.