N-body model of dusty plasmas: Cloudy Ion Wakes

Charged dust grains immersed in a plasma alter the local plasma density and, consequently, the electric potential. This is evident in complex plasma laboratory experiments where the ions flow past the dust grains, creating an ion wake downstream of the grains. Individual ion wakes are modified by the presence of nearby dust grains. The variation of the wake potential as two grains interact depends on the orientation of the grains relative to the ion flow direction and interparticle separation. An N-body simulation of ions and dust, DRIAD [1], has been used to find the total electric potential in the vicinity of dust grains in the presence of flowing ions. However, it is impractical to apply this detailed model for many dusty plasma systems, such as dust crystals containing thousands of dust grains and of millions of ions. Here we develop a model for the dust plus ion wake potential using the results from the DRIAD code for two interacting grains. We use this potential to calculate the forces between dust grains and other grains' ion wakes. We then employ this force model in an n-body code modeling just dust where the ions are modeled through the wake potential. This allows us to model large dust systems and investigate dynamic phenomena such as dust crystal melting.