Intensive vaporization of an aggregate of particles including thermal and ionization disequilibrium in a radiation field

The intensive vaporization into a vacuum of an aggregate of monodispersed metallic particles in a continuous $\rm CO_2$ laser radiation field is studied theoretically in the quasistationary approximation. It is proposed to solve the many-body problem in a single particle approximation where the existence of an aggregate is taken into account by introducing a vapor density that increases in time at infinity (a vapor background). The effect of the aggregate on the vapor halo shows up through the appearance of a density jump at the interface between the vapor from the halo and the background. As evaporation continues the dimensions of the individual haloes shrink. The vapor plasma is regarded as having two temperatures and the ionization disequilibrium is taken into account. The evolution of the parameters of the vapor (density, degree of ionization, temperatures of the heavy and electron components) and of its transparency is studied. The breakdown times for different particle densities and the threshold for collective breakdown are determined.