Using 2d dust structures ot probe plasma conditions

Complex plasmas are of interest as they allow the self-assembly of micron sized dust particles to form both stable and unstable structures. The dust particle interaction with ions flowing towards a negatively charge surface creates an ion wake field, affecting both the charge on the dust grains as well as the electrostatic interaction between the grains. This interaction is partially responsible for the stability of a dust structure. The dust structures can be manipulated by changing the confinement forces of the system, an example of which is placing a glass box on the lower electrode of a modified Gaseous Electronics Conference (GEC) cell. The box allows formation of vertical dust chains. Changing the power of the system can transform a 1D chain to two chains side-by-side, making a 2D zig-zag structure.



The exact role the ion wake has on the stability and how the box modifies the horizontal and vertical confinement are unknown.



A molecular dynamics simulation of ions flowing past dust grains in an experimentally stable configuration is utilized to determine the forces acting on the dust grains and determine the electric field and electron and ion number densities as a function of position within the box. Plasma parameters are determined by an iterative method to find a minimal force-balance for the dust grains. This force-balance equation gives insight into the confining forces acting on the system, and the contribution of the ion wake to the stability of the dust structure.