Particle simulations of ion-extraction process from a decaying plasma assisted by radio-frequency plasma heating

Abstract

In this study, two-dimensional kinetic particle simulations were employed to examine the potential of radio-frequency (rf) plasma heating in enhancing ion extraction efficiency in a decaying plasma with the configuration of parallel plates. The numerical results suggest that the application of rf power based on the direct current electrostatic method leads to a remarkable increase in the ion extraction flux, thereby reducing the time required for ion extraction. The increase in the ion extraction flux is attributed to the enhancement of the penetration ability of the rf electric field into the plasma, especially in cases of high rf frequencies, which can elevate the bulk electron temperature to approach 10 eV. The propagation speed of ion rarefaction waves is enhanced by the increased electron temperature, speeding up the process of ion extraction. The study also found that an increase in rf voltage causes more intense plasma oscillations to screen out the rf disturbance, further increasing the electron temperature. Furthermore, as ion extraction continues, the heating effect of rf frequencies was found to be enhanced due to the decay of plasma density.