Influence of the Electrical Characteristics of Pulsed Microwave Magnetron Power Supply on the Conditions for Plasma Formation in the Vacuum Chamber of Resonator-Type Plasmatron

Abstract

The paper presents the research results of the influence of the electrical characteristics of a pulsed microwave magnetron power supply on the microwave discharge generation conditions, determined by the operating mode of the generating  system as a whole. Plasma was formed in a vacuumized reaction-discharge volume located inside a rectangular resonator chamber. Depending on the operating modes of the microwave magnetron power supply, studies have been conducted for three modes of microwave discharge plasma generation: pulsed mode with a duty factor S ≈ 2; pulsed mode with  a duty factor S ≈ 1.15; continuous mode. Probe measurements of the microwave power in the microwave discharge plasma volume and its local conductivity have been carried out. The paper presents  the dependence of the power of microwave energy in the central area of the reaction-discharge quartz  chamber of a microwave plasmotron on the amount of power consumed by the microwave magnetron, as well as the distribution of the electrical component of the microwave discharge plasma along the length and cross-sectional plane of the working volume. It has been established that for all studied modes of operation  of the power source, with an increase in the power consumption of the microwave generator system, an increase in the microwave power recorded in the central region of the plasma discharge is characteristic. The continuous generation mode is characterized by a decrease in the uneven distribution of electromagnetic energy along the axis of the discharge chamber.  It is shown that the transition from a pulsed to a continuous mode of microwave plasma discharge generation at the same level of power consumption by the generating system is characterized by a decrease in the value of the registered microwave power in the microwave discharge plasma volume and an increase in its local conductivity in particular areas of the reaction-discharge volume.