Ar-H2 double gas puff experiments on the GIT-12 generator

A Z-pinch implosion is now commonly used as a K-shell plasma radiation source. Stability of the imploding shell is a key factor that limits the production of the K-shell radiation, especially, in the case of a long time implosion, or when the implosion starts from a large initial radius. Experiments carried out at HCEI and Maxwell-PI showed that the use of double shell gas puffs and solid fill loads could sufficiently improve implosion stability. As a next step in this direction, it was suggested to add hydrogen to a higher atomic number working gas in order to improve the implosion quality. Our ID-RMHD modelling showed that the addition of hydrogen to the inner shell of double gas puffs leads to a decrease in K-shell radiation yield, However, if the gas mixture is used only in the outer shell, it can improve stability of the outer shell implosion and the final pinch, so an increase in K-shell radiation production can be expected. We report the results of the double gas puff experiments carried out on the GIT-12 generator at the current level of 2.1-2.3 MA. In the experiments we used argon as a working gas in the inner shell and argon-hydrogen mixture in the outer shell.