MODELING OF PLASMA CHEMICAL PROCESSES IN PULSED CORONA DISCHARGES

By a two-dimensional numerical simulation of positive streamers in atm ospheric air in sphere-plane gaps, the G-values (numbers of radicals p er 100 eV of input energy) for the production of oxygen and nitrogen a toms are obtained. Calculated G-values weakly depend on the applied vo ltage and parameters of the gap and are about 3-4 and 0.3-0.4 respecti vely. In the frame of the qualitative theory of streamer propagation i n nonuniform electric fields, approximate formulae for G-values in str eamer corona discharges are derived. The G-values are determined by th e magnitudes of the reaction rate coefficients at electron energies co rresponding to the maximum of the electric field in the streamer head. The formulae obtained describe well the relations between the G-value s for different plasma chemical reactions and can be used for estimati ons of the absolute G-values with an accuracy up to a factor of two.