Study of the mass ratio effect on double gas puff implosion dynamics

Long time implosion experiments with argon double gas puffs have been conducted on the GIT-12 pulsed current generator at the current level of 2.2-2.4 MA. The double gas puff was used as one of the alternative ways to provide a stable implosion at long implosion time. In the experiments the implosion time was in the range from 230 to 340 ns. The results of the experiments were compared to the results of the 2D snow plow simulations. The experiments and the simulations show that the final pinch is sufficiently stable, when the inner-to-outer shell mass ratio is greater than 0.7. The maximum argon K-shell yield obtained in the experiments is equal to 740 J/cm with the radiation power of 220 GW/cm. At the long implosion times, the K-shell yield obtained in the double gas puff implosion is twice as much as the K-shell yield of 4 cm radius single gas puff with the radiation power increased more than an order of magnitude.