Numerical and experimental investigation of the electrical explosion of aulminum wire

Abstract

The physics of electrical explosion of metal wire is extensively investigated since it is of interest for many fundamental applications, such as dense plasma generation, wire-array Z pinch1, etc. Better understanding of the physics of the electrical explosion of metal wire leads to efficient utilization of this technique. With the in-depth experimental investigation of the electrical explosion of metal wire, the method of the numerical investigation is getting emphasized. This paper is devoted to the numerical and experimental investigation of the electrical explosion of aluminum wire in vacuum. The experiments are carried out on a pulsed-current source. A laser probe is applied to construct the interferometry diagnostic. The distribution of the exploding product is estimated from the interference phase shift which is reconstructed from the interferogram. In the numerical investigation of the electrical explosion of aluminum wire, a three-term equation of state is constructed based on the Thomas-Fermi-Kirzhnits model to describe the phase transition of the aluminum wire. The non-ideal Saha equation which is deduced from the dense plasma equation of state2, is applied to calculate the thermal ionization and pressure ionization self-consistently. The model is composed of thermal calculation and magnetohydrodynamics (MHD) model with “cold-start” conditions. The numerical investigation is conducted based on the measured current data. The distribution of the density, current density and magnetic field are derived. The simulated voltage waveform and distribution of density is compared with the experimental results.