Radial Density Distribution of a Warm Dense Plasma Formed by Underwater Electrical Explosion of a Wire

Validity of Equation of States and conductivity models at extreme conditions of matter is very important for Warm Dense Matter and High Energy Density research. In the present research we studied time- and space-resolved evolution of the density (down to 0.07 of solid state density) of a copper and tungsten wires during these wires nanosecond (40 kA, 150 ns) and microsecond1 (30 kA, 1.2 microsecond) timescale electrical explosions in water by applying X-ray backlighting. Namely, a flash X-ray source of 20 ns pulse-width and >60 eV photon energy was used allowing space resolution down to 50 microns. The radial density distributions at different times of wire's explosion obtained by an inverse Abel transform analysis of Xray images were compared with the results of Magnetohydrodynamic simulation coupled with Equation of States, conductivity models, Ohm law and equation of electrical circuit of the pulsed generators used in this research. Also, the obtained values of average conductivity of copper and tungsten were compared with results of these simulations. The validity at different time scales of the Equations of State for copper and tungsten and the conductivity model used in these simulations is discussed.