Underwater microsecond timescale electrical explosions of aluminum and copper foils

Abstract

We present results on underwater electrical explosions of thin aluminum and copper foils using a generator delivering ∼200 kA current amplitude, ∼0.9 μs rise time pulses. Time-resolved shadow imaging displays the generation of a strong planar shock wave in water in the vicinity of the exploding foil. Using time-resolved spectroscopy, aluminum oxide (AlO) absorption bands were observed in a Planckian-like spectrum, indicating that aluminum combustion starts when aluminum vaporizes. It is also shown that the strongest shock wave is obtained for the largest linear energy deposition rate to the foil.