FEATURES OF A NONEQUILIBRIUM MICROWAVE ELECTRODE DISCHARGE

The luminosity structure of a microwave discharge excited in hydrogen and hydrogen-methane mixtures (1-8% methane) between the rod electrode and the plane surface in a cylindrical metallic discharge chamber at a pressure of 1-15 torr and an input power of up to 500 W is studied. The parameters of the charged component of a microwave electrode disch arge are measured by using electric probes. It is shown that electron heating in an electromagnetic field outside the plasma column results in the formation of weakly decaying plasma around the plasma core. Upo n the addition of methane, the probe current and the ion saturation cu rrent decrease as the methane concentration increases. The study of th e structure of a discharge excited by means of a conical electrode sho ws that, in this case, there is a plasma region in which the radial di stribution of the ion saturation current is almost uniform.