Parameters of electrode discharges in supersonic air flows

Results are given of experimental investigations of basic microscopic parameters of plasma of a longitudinal-and-transverse dc discharge in a supersonic wind tunnel with a backward-facing step. The results of measurements of electric field $E$, of temperatures of gas $T_g$ and of excitation of electron levels $T_e$, and of reduced electric field $E/N$ are compared with the measured or previously found parameters of transverse and longitudinal discharges in supersonic flows and in stationary air in a wide range of pressures and currents.