Electron plasma wave in a plasma with non-Maxwellian distribution produced by a large-amplitude wave

Abstract

The electron energy distribution function is measured in the presence of a large-amplitude electron plasma wave, using an electrostatic analyzer. The finite initial damping of the wave is shown to produce an electron beam of detrapped particles. Measurements of linear electron plasma waves, launched simultaneously, show the existence of two dispersion branches which are predicted theoretically, based on a simple model for the measured distribution function. The results are used to consider the role of the detrapped particles for the phenomena related to the large-amplitude electrostatic waves.