Analyzing spatially resolved line spectra emitted by Z pinches

The spatial profiles of key physical variables such as electron temperature and density are crucial in determining the overall radiating efficiency of a Z pinch as well as the emitted photon energy distribution. The present w ork uses spatially resolved x-ray lines emitted from shots taken on the 4 M A Double EAGLE generator [C. Deeney , Phys. Rev. A 44, 6762 (1991)] at Maxw ell Physics International to infer such profiles. The loads were arrays of 15 wires consisting of 95% Al, 5% Si, producing nearly 50 kJ of K-shell rad iation with relatively long pulsewidths of 41-43 ns. It is found that the s patial profile of the He-like intercombination to resonance line ratio is c ritically affected by self-absorption and re-emission (scattering) of reson ance line photons emitted from the hot, dense interior of the pinch. This r atio cannot be correctly interpreted without taking the scattering into acc ount. Also, at densities somewhat lower than those achieved by these pinche s, this line ratio becomes more temperature than density dependent. The inf erred temperature gradient is much less steep than that which had been diag nosed previously for a pinch emitting a much shorter x-ray pulsewidth of 13 ns. (C) 2000 American Institute of Physics. [S1070-664X(00)01808-5].