GENERALIZED MAGNETOHYDRODYNAMIC EQUATIONS FOR PARTIALLY-IONIZED DUSTYMAGNETOPLASMAS - DERIVATION AND APPLICATIONS

A comprehensive investigation of electromagnetic wave and instability phenomena in partially ionized, magnetized dusty plasmas has been carr ied out. By employing the multi-fluid balance equations along with the Maxwell equations, a compact set of coupled field equations for the c ases in which the dust grains are either robust (v(d)-0) or dynamic is derived. These systems of partial differential equations are used to study wave phenomena and resistive tearing mode instabilities analytic ally as well as by means of numerical simulations. For robust dust gra ins, it is shown that coupled sound-Alfven waves can appear even in th e absence of ion-neutral collisions. The unstable tearing modes are co upled to convective drift modes, if the dust number density is inhomog eneous. In the induction equation two new source terms for self-genera tion of magnetic fields can be identified. In parameter regimes that a re characterized by dynamic dust grains, the low-frequency phenomena d evelop on timescales that are governed by the dust particle inertia ra ther than the ion inertia, as it is the case in dust-free plasmas. The results of this investigation should be useful in understanding the p roperties of low-frequency electromagnetic wave phenomena and the form ation of coherent structures in dusty magnetoplasmas whose main consti tuents are negatively charged dust grains, singly charged positive ion s, and neutrals. (C) 1996 American Institute of Physics.