Sensitivity of magnetohydrodynamic calculations to tabular equation of state models for pulsed power-driven metals

The fundamental limits of high-current conduction in metals to large, fast current pulses are of interest to magnetically driven materials physics, thermonuclear fusion, and discovery science. MHD computer simulations adequately model the physics, but rely on an equation of state (EOS), and electrical conductivity (ECON) model to close the system of equations. The evolution of electrically thin wires (Rskin-depth, Ipeak~1 MA, t~100 ns) are simulated with historical and modern EOS/ECON models. Balance between internal energy and the Lorentz force constrains the material to the vaporization curve of the EOS for the bulk of the thin wires and at the surface of the thick rods. It is found that the variability in the slope of the vaporization curve due to uncertainty in the critical point has the greatest influence on the surface expansion velocity. In the case of thick rods, where PDV data has been fielded, calculations can be used to validate the EOS.