Study of longitudinal electron oscillations in a plasma with a cut-off Maxwellian velocity distribution

Abstract

Using a Van Kampen treatment, we study the longitudinal electron oscillations for a plasma with a cut-off Maxwellian velocity distribution. Having defined and computed excitation coefficients in the real w, k plane, we represent this ‘wave density’ through the greyness of this plane. This representation should be useful as a help to the experimenter. Moreover we show the appearance of a slightly damped pole with a phase velocity slightly smaller than the cut-off velocity Vc if this velocity is in the interval 2 to 4VT and a modification of the Landau mode which propagates for higher and higher frequencies when Vc decreases.