Effect of the thermal instability on the conductor electrical explosion

An electrical explosion of thin metal wires at a current rise time of several tens of nanoseconds and at a current density of ∼10 ⁸ A/cm ² was studied. The experimental results with the LC generator (67 nF, 730 nH) at the 5-20 kV voltage are described and compared with the simulation ones. Simulation model used a wire explosion based on the matter phase transfers. A two-dimensional magnetohydrodynamic code 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 owes to the decrease in liquid metal conductivity with temperature increasing and density decreasing. Comparison between the experiment and simulation demonstrates the acceptable coincidence.