Translationally Strongly Non-equilibrium Hot Atom Assemblies and Chemical Laser Pumping

Abstract

Some kinds of chemical lasers are pumped by hot atom reactions with bulk molecules. The relatively high kinetic energy of the hot atoms favors the prevalence of vibrotationally excited product molecules over the non-excited ones, i. e. the creation of the inverse population of the product molecules’ assembly. These hot atoms are produced by the (laser) photolysis of another bulk component or by the disintegration of its molecules by particle beams[1]. So the kinetics of such kind of chemical lasers must include the kinetics of hot atom transport and reactions. Hot atom assemblies are strongly non-equilibrium, so in the present paper we apply to this problem the method of strongly non-equilibrium chemical kinetics proposed in our previous works (see, for ex. ref.[2]. This method is based on the use of the multi-group approximation for the distribution of hot atoms with respect to their kinetic energy[3]. In our previous work[4] the two-group approximation was used to study the chemical laser pumping: all hot atoms belonged to the upper group and all others to the thermal group. In ref.[4] it was recommended to repeat these calculations, but in three-group approximation when two groups are “hot” and the third one is the thermal. That is the subject of the present paper.