Conductor energy losses at 10 MA/cm on Z

Very high current generators are being developed to drive compact loads leading to conductors carrying very high current densities. Losses in conductors include resistive, magnetic field diffusion, pdV work, and material motion contributions. We have designed and executed experiments on Sandia's 100-ns rise time, 20 MA Z accelerator to quantify those losses at current densities reaching 10 MA/cm. In these experiments we delivered nearly 20 MA to both high-current density and low-current density short circuit loads. We used B-dot probes and VISAR techniques to measure the magnetic field near the load. A reduction in the delivered current of /spl sim/15% over the 20 MA peak current prediction made without resistive losses was observed. Comparisons of these data with radiation magneto-hydrodynamics codes (RMHD) are presented. Implications on the efficiency of next generation pulsed power drivers are discussed.