Simulations of Recent Argon Gas-Puff Implosions on Z With Xe and Kr Dopants

An intriguing result is that a small fraction of Xe (0.8% by number in the center jet) can have a significant impact on the emitted K-shell radiation in an Ar gas-puff implosion. This result was recently obtained from a pair of experiments on Sandia National Laboratories Z machine. These shots were Z2603 (with Xe) and Z2605 (without Xe). The pair had similar initial density profiles (outer shell, inner shell, and center jet) but one had the small aforementioned percentage of Xe dopant in the center jet. The resultant Ar K-shell yield was considerably reduced from 373 ± 9% to 129 ± 9% kJ without an analogous change in the total emitted power or total radiation yield. Furthermore, the K-shell power pulse for Z2603 reduced to a broad bimodal, 7 terra watts (TW) pulse, much smaller than the 32 TW conventional single peak for Z2605. Radiation-magnetohydrodynamic simulations presented herein qualitatively reproduce major trends from experiments. Detailed analyses of the implosion dynamics, temperature and density profiles, and emitted radiation agree qualitatively with the previous study. The effect of varying the xenon fraction on K-shell radiation suggests that enhanced Xe concentration reduces K-shell emission by diminishing K-Shell radiation from the central jet.