Analysis of recent aluminum wire array experiments on z with k-shell yields of ~ 3 5 0 kj

Summary form only given. For a relatively low atomic number element such as aluminum, sufficient electron temperature to reach the K- shell stages can be attained by imploding wire loads with a current of only a few mega amperes. Therefore, on Sandia National Laboratories' Z generator (20 MA), the key to achieving very high yields of Al K-shell radiation is to implode and ionize a much higher mass (not hotter temperature) of Al than can be done on more modest machines. This was successfully accomplished, beginning soon after Z started operations. More recent shots have more than doubled Z's initially achieved K-shell yields, mostly by ionizing a greater mass of Al while maintaining sufficient temperatures for good K-shell emissivity. We have analyzed X-ray data from the nested Al array shots Z1519 and Z1520. These experiments reduced some of the highest Al K-shell line opacities yet observed in laboratory plasmas. A key factor in the diagnosis is the presence of Mg lines from that element's 5% component of the Al 5056 alloy. The measured ratio of the Mg to Al lines well exceeds the ~5% one would expect from an optically thin plasma. Reproducing the observed ratio from the two elements is an important constraint on the model diagnosis, and is a key quantitative indicator of the line optical depths