Wave Profile Analysis of the Behavior of SiO\(_{2}\) under Shock Compression

Abstract

Shock-wave experiments are useful to understand the behavior of minerals under the high pressures and temperatures of dynamic events such as explosions and meteorite impacts. The behavior of SiO\(_{2}\) has been extensively studied under shock compression, yet there are still remaining discrepancies concerning its phase transitions and rheological properties. We explore the behavior the SiO\(_{2}\) variety novaculite by examining wave profiles collected in tandem with x-ray diffraction patterns during a shock compression experiment. Analysis of interferometry data gives values for the pressures obtained during compression and constraints on the elastic behavior of novaculite, but poor data quality limits the accuracy and precision of these quantities. We find the Hugoniot Elastic Limit of novaculite to range from 9.13 to 11.99 GPa and find that the elastic wave is overdriven between 37.17 and 45.92 GPa. We observe evidence for a second wave above the plastic wave in shots with pressures from 26.7 to 37.2 GPa, and compare this feature to similar structures seen in profiles of single silicon crystals, z-cut quartz, and potentially y-cut quartz. We find discrepancies between different types of interferometry measurements on the same shot and demonstrate the need for better quality data to successfully understand the wave structures seen in novaculite.