抄録
Effects of an alternating electric field on collisionless drift waves driven by density gradient are investigated theoretically. The alternating electric field is applied along the magnetic field, the frequency of which is close to that of the drift wave. It is assumed that the electron temperature is much greater than that of ions. The applied field is treated as a perturbation like ion-acoustic wave. The contribution of the “nonlinear Landau damping” due to the coupling between the drift and ion-acoustic waves to the damping coefficient, as well as the effect of the frequency shift, is calculated. It is found that the unstable drift waves can be stabilized for the suitable applied intensities. The damping mechanism is caused mainly by the increasing of the frequency of the drift wave. The results are compared with experimental observations.
