Z-pinches with long time implosions is the subject of this paper.The experiments with neon, argon, krypton and xenon implosions have beenconducted on a GIT-12 (Bugaev S P et al 1997 Izv. Vyssh. Uchebn. Zaved.,Fiz40 38) generator at a current level of 2.2-2.5 MA. The goal wasto study an unstable gas puff of large diameter. Attention was focused on thedynamics of the implosion of such a gas puff, namely on the effect of the gaspuff mass and atomic constitution on the macroscopic parameters of theimplosion. It has been established that during the implosion the wavelength ofRT oscillations increases, reaching a value of 0.8-1 cm at the final stage.As this takes place, bubbles appear in the plasma shell bulk. Theunstable implosion of a gas puff with a large atomic weight is accompanied byan increase in the resistance of the gas puff in the run-in phase, to a valueexceeding the Spitzer resistance by two or three orders of magnitude.
Simulations of nozzle gas flow and gas-puff Z-pinch implosions on the Weizmann Z-pinch