Observation of fast expansion velocity with insulating tungsten wires on ∼80 kA facility

Abstract

This paper presents experimental results on the effects of insulating coatings on tungsten planar wire array Z-pinches on an 80 kA, 100 ns current facility. Expansion velocity is obviously increased from ∼0.25 km/s to ∼3.5 km/s by using the insulating coatings. It can be inferred that the wire cores are in gaseous state with this fast expansion velocity. An optical framing camera and laser probing images show that the standard wire arrays have typical ablation process which is similar to their behaviors on mega-ampere facilities. The ablation process and precursor plasma are suppressed for dielectric tungsten wires. The wire array implosion might be improved if these phenomena can be reproduced on Mega-ampere facilities.

Instability growth mitigation study of a dielectric coated metallic wire in a low current Z-pinch configuration

“…Various studies for the electrical explosion of a single wire with and without insulating coatings have been reported showing that the dielectric coating exerts a significant influence, leading to a more uniform explosion [26][27][28][29][30][31][32][33][34][35]. However, there is a limited number of theoretical studies which investigate the involving complex phenomena starting from the solid state.…”