Similarity of hf discharges as active media of gas lasers: Compact CO2 lasers with high-frequency excitation

Abstract

Experimental data on compact CO2 lasers excited by high-frequency and dc discharges stabilized by a transverse magnetic field are analyzed. On the basis of the known dc analogy of a high-frequency discharge and the less known analogy between these two discharges, the possibility of scaling the laser parameters for these methods of pumping the active medium is demonstrated. It is shown that, in this case, the similarity transformations of the plasma parameters are determined from the scale invariance of kinetic Boltzmann's equation for all types of particles and lead, in particular, to strict invariance of gas temperatures in such discharges, which is a deciding factor for high-power lasers. Other similarity invariants of the discharges under consideration alone were also derived; these invariants make it possible to perform a physical simulation of these discharges.