Implosion Of Aluminum Wire Arrays Coated With Magnesium On The 4 Ma Double-eagle Generator

The authors have imploded aluminum wire arrays which were coated with magnesium on the 4 MA Double-EAGLE generator. The mass fraction of the magnesium varied from 0 to 70%. All the arrays were 15 mm in diameter, 2 cm long and, due to current and mass variations, the implosion times ranged from 85 t 95 ns. The aims were two-fold: (1) to investigate yield enhancement due to the mixing of near Z elements; and (2) to study what parts of the initial wire form the bulk of the on-axis pinch. The results they will present show an average increase in yield of 70% over pure aluminum arrays and 30 to 40% over pinches that were predominantly magnesium. This may be due to an effect discussed by J.P. Apruzese et al for Na-Ne near Z mixtures in which the decrease in the opacities of individual lines increased the escape probabilities. Furthermore, the data shows that by a 70:30 A1:Mg mix, the bulk of the radiation comes from the magnesium indicating that the outside of the wires preferentially dominate the heated core of the pinch. This is confirmed by the fact that the magnesium temperature is hotter than the aluminum. They willmore » present this data along with one-dimensional radiation-hydrodynamic and CRE modeling of these pinches.« less