Molecular dynamics simulations of plasma crystal formation including wake effects

Abstract

Molecular dynamics (MD) simulations are used to study dusty plasma crystal formation in three dimensions. The grain interaction model includes a spherically symmetric Debye-Huckel potential, an asymmetric wake potential, and a unidirectional external potential representing gravity and the sheath potential. We use a new form for the wake with ion-neutral collisions that reduce the interaction length of the wake. For the parameters considered, we obtain quasi-ordered structures in which the grains align into well-formed strings in the vertical direction and a more amorphous alignment of the strings themselves. Changes in the vertical alignment as a function of the wake parameters are analyzed.