ASYMPTOTIC THEORY OF BOUNDARY-LAYERS OF WEAKLY IONIZED THERMAL PLASMAS ON EMITTING ELECTRODES

The paper deals with collision-dominated boundary layers of weakly ion ized thermal plasmas on emitting electrodes, The case considered is wh en the dominating ionization mechanism in the plasma is ionization by electron impact, and the dominating recombination mechanism is recombi nation with an electron as a third body, The ratio of the Debye length to the recombination length is treated as a small parameter, and the method of matched asymptotic expansions is employed, Analytical formul as have been obtained for the distributions of the number densities of ions and electrons and of the electrostatic potential in each asympto tic zone. Formulas have been obtained describing the voltage drop in t he boundary layer as a function of the density of the electric current coming from the plasma to the electrode.