Numerical modeling of plasma formation with megagauss magnetic fields

Recently a set of experiments was conducted on thick 1-mm diameter wires (rods) on the Zebra (1MA) machine at the University of Nevada, Reno. The goal of the experiments was to investigate plasma creation on the surface in the presence of megagauss magnetic field. Laser backlighting, photo detectors, and a gated image intensifier were used to measure radial expansion and surface luminosity. A unique type of rod with a machined hourglass shape to eliminate electrode connections was investigated to avoid influence of plasma formed in the vicinity of the usual electrode connections. Reasonably good agreement is found between numerical modeling of radius expansion in time and experimental results obtained from laser diagnostics (shadowgraphs) and intensifier images. Initial efforts are also presented on comparisons between data and a variety of numerical codes used to model this deceptively simple configuration.