Equilibria and Dynamics of Dust in Flowing Plasma

We discuss a framework for performing both th oretical analyse nd s tions of dusty plasma, in which the dust grains interact with each other via a dynam cally-shielded p tenti ), and plasma electrons and ions appear only through a dielectric function that is embedded in Φ(r). If the plasma ions are flowing, Φ(r) is asymmetric upstream and downstream, which has very remarkable consequences. We show that self-bound flowaligned “dust molecules” can form, and that these molecules propel themselves upstream against the flow. For the case of two grains confined within an axisymmetric external potential well, we show that the grains move through a hysteresis cycle, including discontinuous jumps, as the external parameters are slowly varied. If the well is anharmonic, the hysteresis cycle includes oblique (symmetry-breaking) states. We also show several cases where grains can go into large-amplitude self-excited oscillations which persist in spite of friction. Many of these phenomena have been observed, and we shall connect the theory and simulations to experiment.