Study of the Relationship Between Maximum Specific Energy and Wire Diameter During Electrical Explosion of Tungsten Wires

Abstract

Driven by a pulsed current of 1–3 kA in amplitude and 15–30 ns in risetime, electrical explosions of tungsten wires of different diameters (25/18/15/12.5/10 $\mu \text{m}$ ) were carried out. Shadowgraphs as well as interferograms of exploding tungsten wires were obtained with a YAG Laser. The experimental results showed that with the decrease in wire diameter, the maximum specific energy $E_{\mathrm {sm}}$ (the maximum deposition energy per atom), as well as the wire expansion speed has an increase-decrease tendency under both negative and positive current pulses. In order to understand this phenomenon, the specific power $P_{v}$ at the start moment of vaporization was simulated, and the changing tendency of $P_{v}$ versus diameter was found to be similar to that of $E_{\mathbf {sm}}$ versus diameter. Based on the experiments and simulations, we propose that the specific power $P_{v}$ at the evaporating point must also be regarded as an important factor leading to the change in the maximum specific energy $E_{\mathrm {sm}}$ .