Abstract
The radiation from implosions of X-pinches and planar wire arrays, which consist of alloyed Al and Mo wires, on the UNR 1MA ZEBRA generator was studied. Combined, planar-loop X-pinches are good surrogate sources for studying radiative properties of Z-pinch plasmas that can be of small size, high density and high temperature as are standard X-pinches. Further, the X-pinches consist of the wires from different materials and can also exhibit distinct radiation properties. In particular, combined X-pinches studied in this work used an Al 5056 (5% Mg) wire in the anode (cathode) loop and a Mo wire in the cathode (anode) loop. Combined planar wire arrays had from 10 to 15 wires arranged in one plane and consisted of the same two wire materials as used in the X-pinches. We find that planar wire arrays radiate significant peak power. Spatially-resolved and spatially integrated X-ray spectral data as well as time integrated pinhole X-ray images were analyzed. Non-LTE kinetic models were applied to study the axial gradients of electron temperatures and densities in these X-pinch and Z-pinch plasmas. Specifically, X-ray spectra of K-shell Al and Mg, and L-shell Mo were modeled. As a result, we discuss the dependence of the plasma spatial structure, temperature, density, and opacity. The importance of using different materials or alloys for Z-pinch plasma diagnostics is illustrated. (C) 2007 Elsevier B.V. All rights reserved.