PRS experiments with shell-on-shell gas puff loads

Summary form only given. Long implosion time Plasma Radiation Source (PRS) z-pinch experiments have been conducted recently on Double EAGLE and Saturn using shell-on-shell gas puff loads. The shell-on-shell geometry is predicted to mitigate instability growth especially for long (>150 ns) implosion times. We find that the K-shell performance of the shell-on-shell mass distribution equals the best long pulse results generated to date with either single shell or uniform-fill gas loads. We report on recent experiments to optimize the shell-on-shell for both the pinch length and the ratio of the masses in the two shells.