Merger and binary structure formation of two discrete vortices in a background vorticity distribution of a pure electron plasma

Abstract

Observations have shown that two discrete vortices (clumps) immersed in a broad profile of background vorticity merge quickly or form a binary state that lasts for a long period. The different paths of the vortical evolution critically depend on slight differences in the initial background vorticity distribution (BGVD). By a fine control of the BGVD the asymptotic inter-clump distance is found to be a two-valued function of ∇ζb/ζb2, where ζb is the BGV at the initial location of the clumps, corresponding to the merger and the binary state. The multiplicity is removed by considering the degree of depletion of BGVD between two clumps at the time of their proximity in the initial phase.