INFLUENCE OF THE RF DISCHARGE MODE AND ELECTRODE DIELECTRIC COATING ON GAS-FLOW BLOW-OFF

A model is proposed to explain both the mechanism pf high-current capa citive rf discharge blow-off and the absence of low-current and subnor mal discharge blow off. It is shown that in a subnormal discharge ther e is a region where an increase in current density results in an enhan ced number of electrons deposed on the electrode during the rf field h alf-cycle when this electrode is the anode. During the subsequent cath odic half-period, most of the electrons return into the discharge volu me. In this way the current of primary electrons carrying the main par t of the total current in the discharge is formed. The diminishment of electron losses decreases the field strength at the electrode and enh ances the electrode sheath thickness and voltage. The primary electron s accelerated in the sheath form a beam, which enhances the discharge efficiency at the cost of decreasing the strength of the positive colu mn field.