Shock Compression of Quartz to 1.6 TPa: Redefining a Pressure Standard

Abstract

Evaluation of models and theory of high-pressure material response is largely made through comparison with shock wave data, which rely on impedance match standards. The recent use of quartz as a shock wave standard has prompted a need for improved data. We report here on measurements of the quartz Hugoniot curve from 0.1-1.6 TPa. The new data, in agreement with our ab initio calculations, reveal substantial errors in the standard and have immediate ramifications for the equations of state of deuterium, helium, and carbon at pressures relevant to giant planets and other high-energy density conditions.

The properties of hydrogen and helium under extreme conditions

“…However, shock compression cannot access all values of temperature and pressure. Hugoniot states for D 2 up to ∼100 GPa achieved by gas-guns (Nellis et al, 1983a), pulsed laser (Da Silva et al, 1997), magnetically-driven flyers (Knudson and Desjarlais, 2009), and hemispherically converging explosives (Boriskov et al, 2005) are shown in Fig. 1.…”

“…A number of techniques have been developed to produce shocks, including gas guns (Nellis et al, 1983a), laser-driven compression (Collins et al, 1998a,b;Da Silva et al, 1997;Hicks et al, 2009;Sano et al, 2011b), magnetically driven flyers (Knudson and Desjarlais, 2009;Knudson et al, 2001Knudson et al, , 2004, and hemi-spherically converging explosives (Boriskov et al, 2005). Because the shock process is adiabatic, large increases in temperature also occur with the increases in pressure.…”

Megaamps, megagauss, and megabars: Using the Sandia Z Machine to perform extreme material dynamics experiments

“…These data, in conjunction with QMD calculations for quartz, have provided a new understanding of quartz in the multi-Mbar regime. In particular, it appears that the dissociation of quartz extends over a range spanning nearly 100-1000 GPa, much larger than previously expected [12]. This is significant given the prolific use of quartz as a standard in recent multi-Mbar experiments.…”

“…This is significant given the prolific use of quartz as a standard in recent multi-Mbar experiments. In particular, the revision of this standard has resulted in corrections in the inferred density of deuterium of ~10-15% [12]. Even larger corrections may be necessary for higher compressibility materials such as helium [13].…”

Subsystem functionals and the missing ingredient of confinement physics in density functionals

“…The AM05 functional has been used for calculating various material properties of miscellaneous systems [28][29][30][31] and is proven to perform exceptionally well for solids and surfaces. However, the performance is not as good for systems of more localized characters due to the lack of description of confinement physics in the functional as we discussed in Sec.…”