Magnetic diffusion effects on electrically driven flux compression schemes

Summary form only given, as follows. Power amplification in vacuum utilizing electrically driven magnetic flux compression has been introduced and researched recently for efficient drive of z-pinches and other loads operating at sub-100 ns times and very high magnetic fields (tens of megamperes at radii below 1 cm). We present the results of 1 D MHD calculations, in the 1 microsec regime, corresponding to the ECF2 pulsed power generator being built at CEG, France, and the 100 ns regime, corresponding to the Z machine at SNL. These calculations purport to assess the role of magnetic field diffusion through the plasma armature. To evaluate numerical accuracy the equations are solved both in Lagrangian and Eulerian reference frames. We utilize analytic approximations for the equation of state, resistivity and opacity of the Al armature, and compare with results obtained employing SESAME tables. The magnetic field diffusion equation is solved using a mixed finite element algorithm employing an edge-based electric field vector representation.