Determining the effects of wire diameter in tungsten wire array implosions

Initial experiments with 40-mm, 120 and 240 wire arrays on the 18-MA PBFAZ generator have produced 1.85 MJ, 160 TW of x-ray power in a 8.5 ns pulse. These experiments and experiments on Saturn indicated that the pulsewidth was primarily being determined by the diameter of the individual wires. Two dimensional rad-MHD calculations suggest that the thinner the wire, the lower the initial perturbation levels which may seed Rayleigh-Taylor instabilities. In this paper, the authors present results from a wire array scan where the wire number, array diameter and implosion times are held constant. The wire diameter is changed and the charge voltage on the PBFAZ generator is adjusted to keep the implosion time constant. They then measure the pulsewidth as the wire size varies. 2D MHD calculations of the initial wire expansion will also be compared with the level of random density perturbations needed to simulate the implosion in 2D