Ion Wake Contribution to Minimum Energy Configurations of Dust Structures in a Complex Plasma

Abstract

Charged dust grains in a complex plasma can form interesting structures, including single chains, zigzags, and twisted helices. The minimum energy of these configurations has previously been numerically investigated by varying the number of confined dust particles or prolateness of the confinement potential, but ion wake or gravitational potential contributions were not considered. Experimental work in a parallel plate rf discharge plasma has supported the predicted structural transitions, with additional structural symmetries and rf power dependence noted in the structures formed parallel to the electric field.