Uniformity of Electrical Current for Underwater Electrical Wire Array Explosion

Underwater electrical wire array explosion is a promising approach to generating an extreme high pressure condition which plays a vital role in the investigation of high energy density physics 1 . For electrical explosion of a wire array, the simultaneity of phase transition will affect the pressure peak of converging shock wave in the vicinity of implosion axis 2 , thus, the current from pulsed power supply should be evenly distributed to each exploding wire. Two exploding wires in parallel were set in our experiments to study the distribution of current in the wire array, and the current flowing through each wire was obtained using a coaxial shunt resistor. It is found that the current in the two exploding wires will show a significant difference near the melting point, and then the current distributions tend to be uniform because of the negative temperature coefficient of electrical conductivity. After the formation of high-conductivity plasma, the uneven current distribution will reappear, and this non-uniformity behaves differently in different discharge modes, which may be related to ionization mechanisms. In addition, the sensitivity of the current uniformity to the geometric parameter errors of exploding wires is analyzed based on the magneto-hydrodynamic simulation, and the effect of nonuniform current distribution on the converging shock wave is also considered using hydrodynamic calculations.