Construction of a kinetic model for the iodine CH3I photodissociation laser. Calculation of cross-sections and comparison with experiment

Abstract

The known dependence of the reactivity of the methyl radical formed in CH₃I photolysis upon irradiation wavelength has been explicitly introduced in an attempt to derive a kinetic model of the CH₃I laser. The model was used to derive the cross-section for stimulated emission, σ_{3 → 4}= 5.6 × 10^–18 cm², in accordance with other reported values. Furthermore, the model gives a quantitative estimate of the final product concentrations, the effect of sulphur hexafluoride, the time-dependent behaviour of the laser and the gain. These are all in reasonable agreement with previously determined experimental results.