NONLOCAL ELECTRON KINETICS IN DC DISCHARGES

The self-consistent modeling of a DC discharge must consider the spati al dependences introduced by the inhomogeneous structure of the radial field and the density gradient. To start tackling the problem, we dev elop a self-contained formulation to solve the steady-state spatially inhomogeneous electron Boltzmann equation in a plasma positive column. The problem is solved in cylindrical geometry using the classical two -term approximation, with appropriate boundary conditions for the elec tron velocity distribution function, especially at the tube wall. The present formulation is self-contained in the sense that the relationsh ip between the applied maintaining field and the gas pressure, termed the discharge characteristic, is obtained as an eigenvalue solution to the problem. A progress report on the self-consistent solution to thi s nonlocal kinetic problem is also presented.