Analysis of the discharge channel structure upon nanosecond electrical explosion of wires

• Published in: Physics of plasmas 2007-12, Vol.14 (12), p.123502-123502-10
• Main Authors: Tkachenko, S. I., Barishpoltsev, D. V., Ivanenkov, G. V., Romanova, V. M., Ter-Oganesyan, A. E., Mingaleev, A. R., Shelkovenko, T. A., Pikuz, S. A.
• Format: Article
• Language: English
• Subjects: 70 PLASMA PHYSICS AND FUSION TECHNOLOGY; AIR; ELECTRIC CURRENTS; ELECTRIC DISCHARGES; EXPLODING WIRES; LASERS; PLASMA; PULSES; SHOCK WAVES
• ISSN: 1070-664X; 1089-7674
• DOI: 10.1063/1.2817961

The structure of the discharge channel during nanosecond wire explosions has been studied using laser probing. Wires of 25 μ m diameter and 12 mm length were exploded in air and vacuum by 10 kA current pulse having a 50 A ∕ ns rate of rise. Upon electrical explosion of thin wires in the air, the development of shock waves was observed. The propagation of shock waves was analyzed, and it was possible to draw conclusions on the location of the flow of most of the current in the volume of the discharge channel. This permitted distinguishing between two scenarios (shunting and internal) of the interelectrode gap breakdown development. The scenario depends to a large extent on the properties of the exploding wire material. The same two scenarios are valid upon electrical explosion of wire in vacuum. Moreover, if secondary breakdown develops in the internal scenario, the value of the energy deposition in the wire material during explosion in vacuum may be comparable with that found during explosion in air.