On structure of imploding double shell liner

Summary form only given. A double shell load structure allows one to achieve higher liner stability at the final stage of implosion as compared to a single shell. Our experiment attempts to study the cause of the improved stability of the double shell liner. The experiment was done with a neon gas-puff double shell on a microsecond capacitor bank at maximum current of 380 kA. An axial and radial optical streak photography, magnetic loops and XRDs were used for diagnostics. The outer shell is strongly distorted by instabilities, breaking up into a few plasma "jets" before it reaches inner shell initial radius. The axial velocity of the "jets" is directed from the nozzle, which seems to be caused by the initial gas expansion, when gas travels across the electrode gap. The inner shell boundary was observed to be quite stable despite the strong perturbations of the outer shell. The results could possibly be explained by the "plasma flow" switching of the current onto the inner shell. The significant reduction of the line mass near the nozzle during outer shell implosion, caused by the existence of an axial velocity, seems to be the reason for the current switching. Two dimensional snow-plough model was used to simulate implosion process.