Experimental and theoretical study of the electrical properties of a triode reactor

Abstract

Abstract Measurements of time-dependent voltages in a triode plasma reactor are reported, the electrodes of which were powered with high (13.6 MHz) and low (100kHz) frequencies respectively while the vessel wall was grounded. The numerical simulation of these potentials and currents is based on an equivalent circuit model in which three plasma boundary sheaths are considered. Each of these sheaths is modelled by a voltage-dependent capacitor and a diode with an exponential characteristics, connected in parallel. The reactor model together with the external circuits lead to a system of five coupled differential equations for the relevant voltages which is solved by an implicit method. Comparison between the measured and calculated high and low frequency electrode potentials yields good agreement when the plasma electron density is appropriately adjusted.