Kinetics of the electrons in striations of spherical glow discharges

Recent observations of spherical striations lit large-volume nitrogen de discharges with a central anode have stimulated investigations of the nonlocal electron kinetics in these striations by solving the spatially inhomogeneous Boltzmann equation adapted to spherical geometry. Because the radial course of the electric potential is largely unknown in this discharge, different models concerning its radial course have been developed and used. These models are based on the measured radii of the striations and rite assumption that the potential drop between successive striations does not change. As a consequence, with decreasing distance between the striations the electric field strongly increases toward the central anode. It has been found that spherical striations are only obtained if the electric field is strongly modulated. In this case, a highly nonlocal behavior of the velocity distribution function and strongly modulated radial courses of the macroscopic quantities have been obtained.