Decay instability at the ion-sound frequency induced by a large amplitude Bernstein mode in a plasma

Abstract

Experimental results are presented which show that a large-amplitude wave of one of the Bernstein modes, above a certain threshold power, can decay into another Bernstein mode plus a low frequency ion-sound wave. At larger incident amplitudes, a whole spectrum of low-frequency ion waves was observed, with frequencies extending up to the ion plasma frequency. These results are compared with a previous theory and reasonable agreement is achieved.