Recent advances in magneto-hydrodynamic modeling of wire array Z-pinches

Summary form only given. Magneto-hydrodynamic simulations provide a powerful tool for improving our understanding of the complex physical processes underlying the behavior of wire array Z-pinches. With the advent of large scale parallel computing and three dimensional models, it is now becoming possible to model the entire plasma volume with sufficient resolution to capture the important physical phenomena, from the end of the initiation phase right through stagnation. In this talk we use the 3D MHD code Gorgon to show how the growth of separate m=0 like instabilities on each wire eventually merge together to form a global Rayleigh-Taylor instability structure during the implosion of the array as a whole. Detailed comparisons with soft X-ray images and laser interferometry from experiments on the MAGPIE generator are used to bench-mark the model. Results from similar calculations for arrays on the Z generator are compared to the plasma structure observed in radiography and laser shadowgraphy data. To resolve all of the important features, these Z simulations require up to 700 million computational elements and typically run for 3 weeks on up to 400 processors. By analyzing the energy equation within the code, the relative contributions of kinetic energy, Poynting flux, etc. to the production of radiation can be assessed and the limitations imposed by opacity effects and losses in the driving circuit can be highlighted. The application of the code to other pulsed power configurations such as radial and helical wire arrays, X-pinches and laboratory astrophysics experiments is also discussed.