Lower bounds for the kinetic energy and resistance of wire array Z pinches on the Z pulsed-power accelerator

Approximate lower bounds for the kinetic energy and magnetic flux dissipation for tungsten wire arrays on the Z pulsed-power accelerator at Sandia National Laboratories [R. B. Spielman , Phys. Plasmas 5, 2105 (1998)] are obtained. A procedure, extending previous work determining pinch inductance as a function of time [E. M. Waisman , Phys. Plasmas 11, 2009 (2004)], is introduced and applied to electrical and x-ray energy measurements. It employs the pinch energy balance to determine lower bounds for the plasma kinetic energy just before the main pinch reaches the axis and for the magnetic flux dissipation during stagnation. From the lower bound for the dissipated flux, a lower bound for pinch resistance after x-ray peak power is estimated. The results of applying the introduced energy balance procedure to selected tungsten wire array implosions on Z are given. It is believed that this is the first time that a measure of wire array Z-pinch resistance at stagnation is obtained purely from data analysis without recourse to specific assumptions on the plasma motion. (c) 2008 American Institute of Physics.