Experimental Investigations for Planetary Impact of Carbonate Minerals by High Power Laser and X-ray Free Electron Laser (XFEL)

Abstract

Calcite, which is a universal mineral in meteorites and rocky planet surfaces, might be a source of CO and/or CO2 gas components caused by impact processes. In this study, we conducted Hugoniot measurements and in-situ XRD (x-ray diffraction) observations of calcite during shock processes in order to understand shock responses and shock-induced reactions under planetary impact conditions. We newly obtained experimental data of shocked calcite above 100 GPa using a high-power laser shock technique. Our temperature data indicated a large difference from the previous theoretical model as well as some state changes along the Hugoniot. The result of the in-situ XRD observations using an X-ray Free Electron Laser (XFEL) shows the polycrystallization and the melting of calcite during the compressed and released state. Such shock-induced reactions of calcite may affect the estimation of the total energy, the thermal history and the degassing chemical species during planetary impacts.