Comparative analysis of time-resolved and time-integrated x-ray data from long pulse Z-pinch implosions on Saturn

Two series of Al:Mg wire array Z-pinch implosions were performed on the Sat urn pulsed-power generator [R. B. Spielman , in Proceedings of the 2nd Inte rnational Conference on Dense Z-Pinches, Laguna Beach, CA, 1989, edited by N. R. Pereira, J. Davis, and N. Rostoker (American Institute of Physics, Ne w York, 1989), p. 3]. In one series, the wire number was varied, in the oth er, the load mass was varied. In all cases an initial array diameter of 40 mm was maintained. Sufficient x-ray data were obtained in these experiments to allow the plasma conditions to be inferred by matching x-ray data to th at calculated by a collisional-radiative equilibrium (CRE) model. In fittin g the data, the plasma has been assumed to be either uniform [zero dimensio n (0D)] or to vary one-dimensionally (1D) with radius. On one shot, a compa rison of these two methods of data analysis performed with both time-resolv ed and time-integrated data has been carried out. While the same trends in plasma conditions as a function of load mass and wire number are seen, the uniform plasma assumption yields higher electron temperatures, lower core d ensities, but higher K-shell radiating mass fractions than those obtained f rom the 1D assumption. When comparing time-resolved and time-integrated spe ctroscopic data, a pronounced difference is seen in a density-sensitive lin e ratio whose time-resolved values corroborate experimental evidence that m uch of the K-shell radiation is emitted from a high density core plasma of spatial extent less than about 300 mum. (C) 2001 American Institute of Phys ics.