Steady-state saturated photodissociation of bromine molecules in an argon laser radiation field

A theoretical and experimental investigation was made of steady-state saturated photodissociation of diatomic Br₂ molecules in the radiation field of a high-power Ar⁺ laser. The investigations were carried out in a closed reaction vessel using the pressure jump method, the dependence of the pressure jump on the laser radiation intensity being nonlinear. It was shown theoretically that the degree of dissociation and the way in which saturation was achieved depended strongly on the recombination mechanism. From a comparison of theoretical and experimental data, it was possible to establish the recombination mechanism in the pressure range under study and to estimate the recombination constants. An investigation was made of the radial dependence of the molecular density in the laser beam at various pressures. An analysis was made of the influence of particle diffusion, saturation, and recombination processes on the steady-state radial distribution of atoms and molecules. Conditions were determined for which complete photodissociation of molecules can be achieved in a laser beam.