Micro-fluid dynamics via laser–matter interaction: Vortex filament structures, helical instability, reconnection, merging, and undulation

The Richtmyer–Meskhow flow environment was generated by a laser pulse on the rippled surface of an indium target; the supersonic oscillatory shock caused baroclinic deposition of vorticity and subsequent self-organization (SO) into vortex filaments and the family of related phenomena. Vortex filaments merging, stratification of merged filaments, and undulations along the stratified sheet, were observed on the indium target. These SO structures were favourably compared with those obtained by visiometric studies for the gaseous SF6/air and He/air systems. Instead of the turbulent small scale structures that develop in the very late times on gaseous systems, in the case of a metal target very strong surface tension gradients cause the formation of the Marangony structures.