Energy deposition in electrical explosion of silver wire in vacuum

The electrical explosion of metal wire has been encountered in many physical fields, such as wire-array Z pinch, x-ray source, synthesis of nanopowder, etc. The investigation on the resistive part of the electrical explosion of metal wire is very important for wire-array Z pinch. The structure and value of the energy deposition have decisive influence on the stagnation phase in the wire-array Z pinch. In this paper, the energy deposition in the initial stage of the exploding silver wire, which is kind of high-conductivity, fusible metal, is investigated experimentally. The nanosecond negative pulsed-current with magnitude of ~1kA is generated by a capacitor bank with charging voltage of 16kV. The typical energy deposition process is calculated by integrating the products of resistive voltage and current. A laser probe (532nm, 30ps) is applied to construct shadowgraphy diagnostics. The morphology of the exploding high-density products is demonstrated. The structure of the energy deposition, which is derived from the shadowgram, is analyzed.