Properties of the interaction of laser radiation with a gaseous dust medium

It is found that upon irradiation of a mixture of the atmospheric air and carbon particles of size 30—300 μm at a concentration of ~10² cm^-3 by a cw CO₂ laser, the active combustion of particles in the mixture appears when the radiation intensity in the focal region achieves ~10³ W cm^-2. The dependences of the threshold radiation intensity for the evaporation of particles on their radius are obtained for a gaseous dust medium in the form of a free vertical jet of spherical aluminium and carbon microparticles in nitrogen. It is shown that particles of size ~10 μm can be completely evaporated in a focused cw laser beam of power ~10² W.