Systematics of a 12 CM double shellargon Z-pinch for a range of current drives

Summary form only given. We review the behavior of a 12 cm diameter, double shell argon gas puff as used on a variety of pulsed power drivers. Peak currents ranged from 3.5 to 6 MA, and implosion times from 260 ns. In some cases, the drive current was effectively constant after a rapid 100 ns rise; in other cases, the drive was the more conventional linear ramp. Peak K yield was ~12 kJ for the "constant" current at 3.5 MA, >20 kJ for a linear ramp to 3.8 MA, and ~45 kJ for a linear ramp to 5.6 MA. Optimum performance favored the shorter implosion times and for minimal zippering, reduced or no UV preionization. K-shell pulse widths were 3 to 4 times the analytical estimate based on the sound transit time through the plasma column. The fraction of the K yield due to free-bound (continuum) transitions appeared to increase with peak current. These and other systematic trends will be discussed in detail