Experimental Measurements of the Convolute Plasma on the Z-Machine*

Post-hole convolutes are used in large pulsed power devices to combine the current from several self-magnetically insulated transmission lines at the load. The efficiency of Z's post-hole convolute has decreased with increasing electrical power. Losses as high as 20{\%} of the peak current have been recorded on the most lossy shots. Spectroscopic measurements of the plasma that forms in the convolute are underway. Initial results show that there is a strong correlation between convolute plasma density and the load. This presentation will cover convolute plasma behavior and loss current for several load configurations on the Z-Machine. *Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.