Plasma formation in metallic wire Z pinches

Plasma formation in metallic wire Z pinches is modeled using a two-dimensio nal resistive magnetohydrodynamics code. Modified Thomas-Fermi equations of state and dense plasma transport coefficients allow the phase transitions from solid to plasma to be approximated. Results indicate the persistence o f a two-component structure with a cold, dense core embedded within a much boner, low density. m = 0 unstable corona. Extensive benchmark testing agai nst data from a number of single-wire experiments is presented. Artificial laser schlieren and x-ray back-lighting images generated from the code data are compared directly to experimental results. The results were found to b e insensitive to inaccuracies in the equations of state and transport coeff icients. Simulations of individual wires in a wire array show different beh avior to that observed experimentally due to the absence of three-dimension al effects. Simulations with similar conditions to wires in an array show a general trend in the plasma structure at start of implosion from discrete wires with large m = 0 perturbation amplitudes to partially merged wires wi th smaller perturbation amplitudes as the number of wires is increased. Res ults for a wire number scan with aluminum wire arrays on the SATURN generat or suggest that the observed sharp transition to high x-ray power at around 40 wires corresponds to a sharp decrease in m = 0 perturbation amplitude a nd hence a sharp decrease in the seed perturbation for the Rayleigh-Taylor instability.