Low-frequency instability in weakly ionized current-carrying magnetized plasmas. II. Behaviour in high-frequency wave field

Abstract

The effect of the TrivelpieceGould mode on the behaviour of a low-frequency drih instability in a weakly ionized magnetized plasma is studied experimentally in a DC argon discharge. The ions are weakly magnetized, i.e. S2,v,, pi -R (n,i and pi are the ion gymfrequenty and gyroradius, y is the ion-neutral collision frequency and R is the plasma radius). With increasing amplitude of the high-frequency field, the frequency and the amplitude of the instability decrease. Since the anomalously enhanced ambipolar field is considered as a very important factor in the mechanism driving the instability. special attention is paid to its variation with increasing high-frequency power. The nonlinear mechanisms of the dynamical control of the instability are discussed.