A diffusion-controlled regime of cylindrical inductive discharges

A fluid-plasma model of diffusion-controlled cylindrical inductive discharges in an argon gas is presented. The plasma-field structure of the discharge obtained is completed by the interrelated behaviour of concentrations of charged particles, electron temperature, power absorbed on average by an electron, radial distribution of the components of the high-frequency field, of the Joule heating and of the high-frequency current density in the plasma. The self-consistency of the model and its validity over a wide pressure range (p = (0.05–5) Torr) is reached by involving detailed treatment of the electron energy balance, of the nonlinear processes in the charged particle balance and of the momentum equations. By accounting for the velocity dependence of the elastic electron–neutral collision frequency, concepts from the kinetic plasma theory are introduced in a fluid-plasma description of the discharge. The analysis of the results is in terms of changing gas pressure, power and frequency of the maintenance field. The changes of the parameters of the external coil due to the plasma loading in the coil are also discussed.