New results on planar wire array implosions and their comparison with cylindrical wire arrays on the 1 MA zebra generator

Abstract

Summary form only given. Planar wire arrays were shown to produce the strong power and yield in EUV/X-ray region. The new results of the total radiation yield E <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">t</sub> , time-resolved sub-keV and keV outputs, X-ray spectra and images from ten wire planar arrays from low-to high-Z <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">a</sub> materials were collected recently on Zebra at UNR. Data were compared with the similar mass cylindrical wire arrays results. Planar arrays were characterized by a short rise-time of a single radiation peak: up to 8 ns for sub-keV radiation and near 2 ns in keV and harder X-ray regions, and much higher peak power compared to cylindrical arrays usually having precursor and main peak with a fastest rise-time >10-15 ns. The largest E <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">t</sub> >18 kJ was found for Cu and Mo planar arrays (up to 25% from an energy delivered to a load) that is higher than a maximum E <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">t</sub> ap15-16 kJ for Cu or 10 kJ for Alumel (Ni) cylindrical arrays. The radiating imploding plasma is strongly inhomogeneous. The plasma (few-mm thick in the EUV/sub-keV region) has within itself hundred-mum scale structures on the axis (in several keV quanta). The electron temperatures up to 800-1000 eV were estimated for Mo planar arrays that are much higher than for cylindrical arrays and comparable with the values for X-pinches. The implosion dynamics of wire arrays were studied using spectral and imaging techniques. The results were compared with radiation and MHD modeling