  We study the expansion of a strongly coupled, non-neutral, and cylindrically
arranged ion plasma into the vacuum. The plasma is made from cold rubidium
atoms in a magneto-optical trap (MOT) and is formed via ultraviolet
photoionization. Higher-density and lower-density plasmas are studied to
exhibit different aspects indicative of strong coupling. In a higher-density
regime, we report on the formation and persistence of plasma shock fronts, as
well as external-field-induced plasma focusing effects. In the lower-density
regime, conditions are ideal to observe the development and evolution of
nearest-neighbor ion correlations, as well as geometry-induced asymmetries in
the pair correlation function. Simulated results from a trajectory model and a
fluid model are in good agreement with the measurements.
