Argon Z-pinch experiments on decade quad

Summary form only given, as follows. An argon double-shell gas puff source was fielded on Decade Quad, which was configured in the PRS mode with the four modules combined into a single pulse power driver. In a series of six shots, four of which were taken at reduced Marx charge (70 kV vs. 85 kV full charge), we demonstrated 29 kJ of K-shell radiation in an 11 ns FWHM radiation pulse at 4.6 MA peak current. Current scaling from a 4.1 MA, 18 kJ test was 13.6. Plasma parameters were measured with an x-ray pinhole camera and a spectrometer, both recorded with CCD cameras. The electron temperature was 1600 eV and the ion density 1.5/spl times/10/sup 19/ cm/sup -3/. The K-shell emitting diameter was 3.1 nm. Four B-dot probes in a load anode ring measured the current; the yield was measured with a set of three tantalum calorimeters. The four current probes agreed to within 3%, the calorimeters to within 2%. Although there is an insufficient database to be precise; the optimal implosion time was approximately 210 ns; the shot described above had an implosion time of 214 ns. This reflects the fact that the nozzle was designed for 200 ns implosions (/spl eta/=2) on Double-EAGLE and thus did not tap the full potential of Decade Quad, which has a 300 ns quarter period (which would produce /spl eta/=0.7 with the present nozzle). In this paper, we will discuss the design and detailed results of the experiment.