Beschreibung:
<jats:p>The one-dimensional electrostatic oscillations of a plasma are investigated under the influence of an alternating external electric field. If the motion of ions is ignored, it is shown that there is no influence of the external field on the stability of the plasma, even nonlinearly. The motion of the ions is taken into account by an expansion with respect to the mass ratio α = m−/m+. A dispersion relation for linear plasma oscillations is derived and investigated for different limiting cases. The influence of the external field is shown to be destabilizing on the electron-electron two-stream instability for all frequencies and amplitudes.</jats:p>