Shock Compression of a Fifth Period Element: Liquid Xenon to 840 GPa

Current equation of state (EOS) models for xenon show substantial differences in the Hugoniot above 100 GPa, prompting the need for an improved understanding of xenon’s behavior at extreme conditions. We performed shock compression experiments on liquid xenon to determine the Hugoniot up to 840 GPa, using these results to validate density functional theory (DFT) simulations. Despite the nearly fivefold compression, we find that the limiting Thomas-Fermi theory, exact in the high density limit, does not accurately describe the system. Combining the experimental data and DFT calculations, we developed a free-energy-based, multiphase EOS capable of describing xenon over a wide range of pressures and temperatures.

Figure 1

Left: The $Z$ shock compression experiments. Right: Representative VISAR data. Impact and shock transitions are indicated by the sharp changes in the VISAR signal.

Figure 2

Top: $U_S\mathrm{\text{−}}{U}_P$ Hugoniot plot. Filled black circles, $Z$ data (this work); green square, Ref. 38; purple square, Ref. 39; orange square, Ref. 40; red circle, LDA (this work); blue circle, AM05 (this work); blue line, SESAME 5190; red line, LEOS 540; black line, 5191 (this work). Bottom: Absolute difference from the linear fit to experimental data. Experimental uncertainty is on the order of the data symbol, unless indicated otherwise.

Figure 3

$P\mathrm{\text{−}}\rho$ Hugoniot plot. Lines and symbols as in Fig. 2. Black dashed line, 5191 298 K isotherm; blue triangles, solid xenon compression data [17]. Also indicated are Hugoniot temperatures calculated using 5191. Our DFT calculated isotherm [37] agrees with the experimental data [17].