Structures and dynamics of fine particles in fine particle plasmas under microgravity and friction between two-dimensional layers of charges

Abstract

Low temperature structures and dynamics of fine (dust) particles in the ambient (background) plasma with the cylindrical symmetry are analyzed by numerical simulations and theory. Fine particles are modeled as Yukawa particles and the one- and two-component cases are considered. In the one-component case, particles form well-defined concentric cylindrical shells and the structures are expressed by simple interpolation formulas to a good accuracy. When we introduce the difference into charges of particles forming a shell, particles are separated into a smaller shell of larger charges and a larger shell of smaller charges. In the two-component Yukawa system, we usually have structures composed of charge-separated shells where larger and smaller charges appear alternately in the order of radius. When we have charge-dependent forces along the symmetry axis, shells of larger and smaller charges can move relative to each other keeping their own structures and the mobility for the relative motion can be defined. We give examples obtained for some combinations of parameters. It is found that, when appropriate conditions are satisfied, concentric shells form a kind of 'fine-particle (dust) screw' and the mobility is increased.