Maximum Energy Deposition During Resistive Stage and Overvoltage at Current Driven Nanosecond Wire Explosion

A wire explosion in a gaseous and condensed media extends possibilities of studying of phase transition of the wire material. The copper and tungsten wires of the diameter of d=25 mum were exploded in vacuum, air, and water by current pulse with the rate increase of ~ 50 A/ns. Energy deposited into the wires at different stages of explosion in the media and maximum voltage reached during wire explosion was estimated from the experiments. Laser probing measurements were performed with the second harmonic of a YAG:Nd⁺³ laser (lambda=0.53 mum; Deltat=10 ns). Shadow images of the expanding wire materials and shock waves leading the explosion were obtained at different times during the discharge