THEORETICAL ASPECTS OF THE METAL-ELECTRONEGATIVE PLASMA INTERFACE

The sheath zone which occurs near a metallic plane immersed in an elec tronegative plasma is analysed. A new theoretical model for the sheath zone, which includes the presence of negative ions in the plasma and the effect of a finite positive ion temperature value, was used to obt ain the dependence of several quantities of interest on the plasma par ameters. The following quantities have been analysed: the Bohm criteri on, the floating potential, particle densities, and current densities at the plane, impact energies of particles at the plane and the sheath thickness.