Effect of dust charge fluctuations on Kelvin–Helmholtz instability in a cold dust plasma

Abstract

Effect of dust charge fluctuations on Kelvin–Helmholtz (K–H) instability driven by sheared dust flow with both perpendicular and parallel components to magnetic field is investigated in magnetized three-component cold dust plasma. It is found that K–H instabilities are mainly driven by the parallel component of the sheared dust flow. The perpendicular component of the sheared dust flow influences the extent of the oblique propagation of the unstable perturbed wave with respect to the ambient magnetic field. For a dense dust plasma, as the perturbed frequency is much higher than the dust charging frequency, the maximum damping rate of the perturbed wave due to dust charge fluctuations will reach the order of the dust charging frequency. In this case, the critical shear for the parallel K–H instability increases rapidly because of the charging processes in the long-wavelength perturbation.