A computer simulation of the plasma resonance probe

Abstract

A numerical experiment is described in which a one-dimensional plasma model is used to simulate the resonance probe. The trajectories of a large number of plane electron sheets are followed in a self-consistent calculation which takes account of a spatially dependent but smeared-out ion background, and externally applied static and r.f. potentials. No differentiation between sheath and plasma regions is introduced, nor is there any linearization.The typical resonant rectification curves, with resonance below ωp, are obtained. A comparison is made between the plasma behaviour at resonance and in frequency ranges above and below the resonance. For example, the phase of current collection w.r.t. probe potential is studied. Fourier analysis of potential and density variations is used to obtain further information on phase relationships. Orbit diagrams of electrons forming the current under resonant conditions are presented, and a model for the mechanism of resonant rectification in terms of electrons at the sheath edge put forward.