Large diameter (45-80 mm) nested stainless steel wire arrays at the Z accelerator

Experiments have been performed at the Z accelerator to elucidate the effects of initial load diameter on the radiated output of a 7 keV wire array x-ray source. Nested wire arrays with initial outer diameters of 45-80 mm were fielded, with the masses chosen to maintain a nominally constant coupling to the Z generator. The total radiated output decreased from similar to 1.1 MJ to 0.5 MJ for the largest diameter arrays, while the > 1 keV and K-shell radiation decreased at both small and large diameters. The >1 keV output peaked at similar to 340 kJ, while the K-shell yield peaked at similar to 55 kJ. The observed trends in radiated output and stagnated plasma parameters are consistent with a phenomenological K-shell scaling theory, and are reproduced in one-dimensional modeling, although multidimensional effects, such as, growth of the Rayleigh-Taylor instability, are observed in the experiments and appear to impact the stagnated plasma for the larger diameter arrays. (C) 2008 American Institute of Physics.