Modelling of two differently sized dust species in plasmas under micro-gravity

Abstract

A self-consistent two-dimensional hydrodynamic model for a dusty argon plasma has been developed to model more than one dust species. Results are presented for situations where dust particles with two different diameters have been included. The final steady state solution is achieved after three injection steps of the dust particles. At every injection phase dust particles of only one size are let in and the simulation is continued until the steady state solution is achieved. Results show that the differently sized dust particles form crystals at different positions. These dust clouds have an influence on each other by means of positive space charge layers created due to the argon ions, which cannot match the steep dust crystal boundaries. The screened Coulomb interaction between the two differently sized dust species is neglected. The electric potential, ion density, electron density and electron energy show significant changes after each injection phase, even at an amount of dust that is small compared to that studied during the micro-gravity experiments.