Ion Wake Influence on Dust Structure Transitions

Anisotropy of electrostatic confinement is known to influence the formation of ordered dust structures in a complex ('dusty') plasma. However, confinement alone may not fully describe metastable or transitional structures, which depend upon prior experimental conditions as well as present confinement. These lingering effects may represent a persistent plasma response to the dust, containing information about previous states. The same electric field that traps negatively charged dust also imposes an ion flow, accumulating positive charge downstream from dust in an ion wake. The ion wakes modify interactions between dust grains, while the dust modifies the charge and location of ion wakes. Here we present the results from molecular dynamics simulations modeling the motion of ions and dust, focusing on the role of ion wakes during the transition between stable dust structures.