Calculations of kinetic behavior in the supersonic expansion of a helium plasma in a Laval nozzle

The problem of the expansion of a dense, low-temperature helium plasma in a Laval nozzle is considered. The equations of level-by-level kinetics are solved numerically together with the equations of plasma dynamics in a quasi-one-dimensional approximation. The results of the calculations and the dependence of the solutions on the initial conditions in the critical cross section are discussed. The solutions are compared with a model approximation of a stationary sink and experimental results, showing their satisfactory agreement