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Instabilities can affect the quality of flux compression and other high-current experiments. The modeling of such experiments involves a number of numerical difficulties. One such difficulty is the selection of proper material property models. This paper investigates the effect of different electrical resistivity models on the development of the m = 0 instability in a single cylindrical conductor driven by a current typical of the Atlas generator. The nonlinear development of this magnetohydrodynamic (MHD) instability can lead to current disruption. An important challenge for modeling is to predict the maximum magnetic field on a rod surface that can be obtained prior to disruption. This problem can also be generalized to the more complicated moving liner problem. LA series of 2-D MHD simulations was performed with the state-of-the-art MHRDR code to conduct a sensitivity study. Results indicate that the development and growth of m = 0 instability is sensitive to the resistivity models used. Furthermore, it was observed that models with lower values of resistivity near the metal-insulator transition produce higher growth-rate sausage instability. [ABSTRACT FROM AUTHOR]

Plasma formation from thick Al rods ohmically heated during the diffusion of pulsed multimegagauss magnetic field is examined experimentally. Rods in the Z-pinch configuration are driven to 1.0-MA peak current. The evolution of the resultant surface plasma is complex yet highly reproducible. Surface plasmas first form at discrete hot spots. As the pulsed current grows, plasma filaments form, first along the current, and then transverse to it. As the plasma temperature rises, emissions become increasingly uniform until instabilities grow and modulate the surface. [ABSTRACT FROM AUTHOR]