Exploring the formation and evolution of plasma in single exploding wire experiments

Summary form only given, as follows. An exploding single wire experiment was performed using a /spl sim/250 ns pulser with a rise time of /spl sim/20 A/ns. It was found that wires first experienced a resistive heating phase that lasted for 50-80 ns before a rapid collapse of voltage. From that point on, the voltage across the wire and plasma was negligible while the current continued to increase. Previous experiments will be presented that show the existence of plasma extending to 200 /spl mu/m from the wire core at the time of voltage collapse. New spectral data will be presented that indicates whether this initial plasma is composed of surface contaminants or metal. Also, a special wire holder was constructed that allowed the transfer of current from the wire to surrounding plasma to be observed. The effects of radial electric fields on the plasma will also be examined.