Current progress in the modeling of weakly ionized plasmas in contact with electrodes and insulated walls

The paper gives an overview of different methods to describe weakly ionized plasmas and their spatial structure caused by contact with material walls. Emphasis is placed on the microphysical description of the electron component and of its non-equilibrium behavior in low-pressure plasmas. Much effort has been spent in the last years to expand the electron kinetic description to spatially inhomogeneous plasma situations. The most important methods that are currently used for the modeling of low-pressure plasmas, their requirements and availability are discussed. Specific features of new methods for the space-dependent kinetic treatment of electrons, and for the self-consistent description of spatially structured steady-state plasmas are presented by means of three examples. In particular, the electron kinetic behavior in the cathode region and in front of an anode in DC discharges, as well as the space-charge confinement of a column plasma bounded by dielectric walls, is discussed. As a consequence of the non-equilibrium electron kinetics, electron particle and energy fluxes become of considerable importance for establishment of the plasma properties. Plasma–wall interaction processes also have a significant impact on the bulk plasma.