Controlling the structure of a glow discharge by supersonic gas
 flow

The effect of supersonic gas flow on glow discharge characteristics in interelectrode space is studied. First, gas outflow through a Laval nozzle with a central body was simulated: gas particle density distributions, gas flow velocity, Mach number, and temperature were obtained. Next, these profiles were used for numerical calculations of the parameters of a transverse glow discharge within the framework of an extended fluid description of the plasma. As a result, it was found that the cathode zones can both shrink and stretch depending on the parameters of the supersonic gas flow. The latter creates an inhomogeneous gas density in the interelectrode region and thereby affects the value of E/N, which determines the electrical characteristics of the discharge. Numerical simulation results are confirmed by experimental data.