Microwave plasma in non-uniform quasi-static fields with radial symmetry

Abstract

The characteristics of hydrogen plasma in quasi-static microwave fields with radial symmetry have been simulated. The balance equation for the charged particles, the equation for microwave electric field strength and the Boltzman equation have been solved self-consistently, and the stationary distributions of plasma density and electric field settled as a result of processes of ionization, diffusion and bulk electron-ion recombination have been obtained. The simulations have been carried out for hydrogen with parameter νen/ω within the range 0.15-1.73 and the power absorbed in plasma changed from 0.5 to 20 W. It was shown that for low absorbed power, the discharge was presented by a thin electrode plasma layer with the electron density everywhere below the critical value. At higher levels of the absorbed power, the electron density was just above the critical value. The size of the plasma grew proportionally to further rise of the power, but the electron density stayed at the same level. Simulations of the dissociation of hydrogen have also been carried out. The dissociation was mainly determined by the fields inside the plasma formation, and not by a thin peak of the electric field near the internal electrode.