Ethane-xenon mixtures under shock conditions

TL;DR

This study combines DFT-MD simulations and shock experiments to analyze the thermodynamic behavior of ethane-xenon mixtures under high-pressure shock conditions, revealing dissociation processes and validating computational models.

Contribution

It provides a validated computational approach to study molecular mixing and dissociation in ethane-xenon mixtures under shock conditions, linking simulations with experimental data.

Findings

DFT-MD simulations agree with shock experiment data.

Dissociation in ethane correlates with sharp Hugoniot rise.

Mixture composition affects dissociation and temperature profiles.

Abstract

Mixtures of light elements with heavy elements are important in inertial confinement fusion and planetary science. We explore the physics of molecular scale mixing through a validation study of equation of state (EOS) properties. Density functional theory molecular dynamics (DFT-MD) at elevated-temperature and pressure is used to obtain the thermodynamic state properties of pure xenon, ethane, and various compressed mixture compositions along their principal Hugoniots. To validate these simulations, we have performed shock compression experiments using the Sandia Z-Machine. A bond tracking analysis correlates the sharp rise in the Hugoniot curve with the completion of dissociation in ethane. The DFT-based simulation results compare well with the experimental data along the principal Hugoniots and are used to provide insight into the dissociation and temperature along the Hugoniots as a function of mixture composition.