Experiments on two-dimensional vortex patterns

The evolution of a strongly magnetized electron system is identical to that of an ideal two-dimensional (2-D) fluid; an electron column is equivalent to a fluid vortex. We have studied the stability of 2-D vortex patterns with electron columns confined in a Malmberg–Penning trap. The following cases are presented: the stability of N vortices arranged in a ring; the stability of N vortices arranged in a ring with a central vortex; the stability of more complicated vortex patterns.