A numerical investigation of the current and density distributions for a non-equilibrium plasma in a segmented electrode duct

Abstract

Current and density distributions for the non-equilibrium plasma in a segmented electrode duct are computed for values of the electron Hall parameter between 0 and 10. A two-dimensional, time-dependent numerical model is used. It is found that the behaviour of the plasma depends on its stability to electrothermal waves, and the ratio of segmentation length to electrode pair separation, L/H. In the unstable regime the current flow is dominated by the presence of streamers, which are approximately one-dimensional. For L/H of order unity the streamers have a beneficial influence on current conduction, i.e., the non-equilibrium plasma duct possesses a lower internal impedance than the uniform plasma duct for the same average electrical conductivity, Hall parameter and duct dimensions. For L/H much less than unity the reverse is true.