Dust-lower-hybrid instability in the presence of dust charge fluctuation in a streaming dusty plasma

A detailed theoretical investigation has been made on the properties and excitation of low-frequency and low-phase-velocity electrostatic dust-modes in a magnetized dusty plasma including the streaming of ions, dust charge fluctuation, and the kinetic effects using the Vlasov-Poisson analysis. In the case of high-density dusty plasma, the dust-lower-hybrid (dlh) mode propagating nearly transverse to the external static magnetic field is obtained. On the other hand, for the low-density dusty plasma, the dust-acoustic (DA) wave propagating nearly perpendicular to the external magnetic field has been obtained. It is found that in any case of the above dust-modes, the Landau damping linearly adds to the damping due to dust charge fluctuation. These low-frequency modes can be excited when the ion streaming velocity exceeds the parallel phase velocity of the mode provided the damping due to the dust charge fluctuation is smaller than the Landau damping term of the respective mode. Moreover, it is found that the DA mode is damped rapidly compared to the dlh-mode through charge fluctuation and Landau damping processes. (C) 2002 American Institute of Physics.