Extension of the Hugoniot and analytical release model of α-quartz to 0.2–3 TPa

In recent years, α-quartz has been used prolifically as an impedance matching standard in shock wave experiments in the multi-Mbar regime (1 Mbar = 100 GPa = 0.1 TPa). This is due to the fact that above ∼90–100 GPa along the principal Hugoniot α-quartz becomes reflective, and thus, shock velocities can be measured to high precision using velocity interferometry. The Hugoniot and release of α-quartz have been studied extensively, enabling the development of an analytical release model for use in impedance matching. However, this analytical release model has only been validated over a range of 300–1200 GPa (0.3–1.2 TPa). Here, we extend this analytical model to 200–3000 GPa (0.2–3 TPa) through additional α-quartz Hugoniot and release measurements, as well as first-principles molecular dynamics calculations.