Continued development of a 12 cm diameter nozzle for argon Z-pinches

Summary form only given. We report on how the K-shell output of an argon Z-pinch optimizes as a function of the radial gas distribution. The tests, conducted on the Double Eagle simulator at /spl sim/4 MA peak current, utilized a large diameter double-shell nozzle that was designed for use with the 300 ns rise-time current pulse (/spl sim/6 MA) of the DECADE QUAD (DQ) pulsed power machine. By varying the plena gas pressures of the inner and outer shells, the net radial distribution could be changed from one that was strongly concentrated on-axis to one broadly distributed as a function of radius. Previous work has shown that a uniform distribution gives higher X-ray output than shell-like flows for gas Z-pinches. The present work is focused on defining the optimum distribution in more detail and to establish benchmarks for 2D MHD calculations.