1 Dust-Acoustic Waves Driven by an Ion-Dust Streaming Instability in

Dust acoustic waves (DAW) are spontaneously excited in dusty plasmas produced in dc and rf discharge plasmas over a wide range of plasma and dust conditions. A common feature of these plasmas is the presence of an ion drift relative to the dust, which is driven by an electric field, Eo in the discharge. Using a three fluid model of the DAWs, including the zero order electric field and collisions of all species with the background neutral gas (pressure Po), DAW stability curves were obtained in the Eo−Po plane, for various dust and wave parameters. The (Eo, Po) data points from several experiments in which DAWs have been observed are also shown in comparison to the theoretical stability boundaries. This analysis supports the conclusion that the DAWs are excited by an ion-dust streaming instability