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

摘要

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 μm) 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 Esm (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 Pv at the start moment of vaporization was simulated, and the changing tendency of Pv versus diameter was found to be similar to that of Esm versus diameter. Based on the experiments and simulations, we propose that the specific power Pv at the evaporating point must also be regarded as an important factor leading to the change in the maximum specific energy Esm.