Wire explosion in vacuum: Simulation of a striation appearance

Abstract

This paper presents the simulation results of electrical explosion of thin $\mathrm{Al}$ wires at a current rise time of several tens of nanoseconds and at a current density of ${\text{∼10}}^8\hspace{0.5em}\mathrm{A}/{\mathrm{cm}}^2$ . Studies include the matter phase transfers and magnetohydrodynamic (MHD) model. A two-dimensional MHD model based on the particle-in-cell method is used to consider the formation of striations and a low-density plasma corona surrounding the wire. The striations are shown to occur through evolving overheat instabilities early in the explosion, when the conductor material is in the liquid or two-phase states. The process results from the decrease in liquid metal conductivity with increasing temperature and decreasing density.