Instability of plasma-dust systems with a macroparticle charge gradient

An analysis is made of various self-oscillations which appear in plasma-dus t systems with spatially varying macroparticle charges. The conditions of e stablishment and the nature of the evolution of the two main types of insta bility of these systems are analyzed. Particular attention is paid to cases of vortex particle motion. Dust systems having parameters similar to those in laboratory experiments are modeled numerically. Calculations were made for charged particles in an external electric field and in the Earth's grav itational field using a molecular dynamics method. (C) 2000 MAIK "Nauka/Int erperiodica".