DISPERSION PROPERTIES OF LOW-FREQUENCY WAVES IN MAGNETIZED DUSTY PLASMAS WITH DUST SIZE DISTRIBUTION

Dispersion properties of some low-frequency modes in magnetized dusty plasmas have been investigated theoretically, taking into account the dust size distribution. In contrast to earlier work on dispersion prop erties of different modes in magnetized dusty plasmas with a single du st size, it is assumed that the dust grains are distributed in size. A ssuming that the dust size is given by a power law distribution, with a nonzero minimum and finite maximum grain size, the effect of dust si ze distribution on the dispersion properties of some electrostatic and electromagnetic modes in magnetized dusty plasmas is investigated. It is seen that in the very low-frequency (VLF) regime, taking into acco unt the size distribution leads to a new kind of damping for an electr ostatic dust-cyclotron and right-handed circularly polarized (RCP) ele ctromagnetic Alfven mode, whereas the left-handed circularly polarized (LCP) Alfven mode remains undamped. In the low-frequency (LF) regime, size distribution results only in the modification of the dispersion relations for all the modes. (C) 1996 American Institute of Physics.