Neon and argon multi-nozzle gas puff z-pinch studies on COBRA

In the past, we have produced stable z-pinch implosions with an outer Ne shell imploding on an inner Ar (Ne-on-Ar) gas puff load. Using a similar mass density profile to the Ne-on-Ar experiments, we observed that Ar-on-Ne implosions were not stable. In this paper, we present the investigations of the Ne-on-Ar and Ar-on-Ne implosion dynamics with various mass density profiles. The experiments are conducted on the 1-MA, 200-ns COBRA generator. A triple-nozzle is used to produce z-pinch loads with concentric outer and inner annular gas puffs and a center gas puff. Z-pinch loads such as Ne-on-Ar and Ar-on-Ne with or without a center gas jet will be tested.