Dust vortex flow analysis in weakly magnetized plasma

Abstract

Analysis of driven dust vortex flow is presented in a weakly magnetized plasma. The 2D hydrodynamic model is applied to the confined dust cloud in a non-uniform magnetic field in order to recover the dust vortex flow driven in a conservative force field setup, in the absence of any non-conservative fields or dust charge variation. Although the time independent electric and magnetic fields included in the analysis provide conservative forcing mechanisms, when a drift based mechanism, recently observed in a dusty plasma experiment by M. Puttscher and A. Melzer [Phys. Plasmas 21, 123704 (2014)] is considered, the dust vortex flow solutions are shown to be recovered. We have examined the case where a purely ambipolar electric field, generated by polarization produced by the electron E×B drift, drives the dust flow. A sheared E×B drift flow is facilitated by the magnetic field gradient, driving the vortex flow in the absence of ion drag. The analytical stream-function solutions have been analyzed with varying magnetic field strengths, gradients, and kinematic viscosities of the dust fluid. The effect of the B field gradient is analyzed which contrasts that of the E field gradient present in the plasma sheath.