Real Time X-ray Diffraction and Imaging of Shock-Compressed Geological Materials
Abstract
The behavior of materials under dynamic compression is of strong interest for applications to problems in Earth and planetary science ranging from the effects of impacts and explosions to the synthesis of new phases and materials. The high-pressure dynamic response of geological materials is critical for understanding weapons effects and ground shock propagation in geological materials. Detailed and accurate experimental data are needed for incorporation into computer simulations of impacts for many applications. In this project, we will use the new Dynamic Compression Sector at the Advanced Photon Source to carry out real-time x-ray diffraction and imaging experiments on shock-compressed minerals. The coupling of dynamic compression with high brightness, high energy, tunable x-rays at a premier synchrotron facility will provide for the first time the capability to carry out crystallographic measurements under in situ conditions and to directly image ongoing deformation processes. Our initial focus will be on the study of phase transitions in quartz under dynamic compression. Quartz is one of the most abundant minerals of Earth’s crust and is widely distributed in different rock types. It has been the subject of extensive experimental studies due to its role as an archetype for the silicate minerals of the crust and mantle. Under static high pressures and temperatures, quartz undergoes well-characterized transitions to denser phases. However, the behavior of quartz under dynamic compression is very different from its static behavior and is illustrative of the complicated dynamic response of silicate minerals and rocks. In this project we will shock compress quartz and fused silica samples to pressures as high as 600,000 bars and carry out x-ray diffraction experiments to determine the lattice-level crystal structure of quartz under dynamic loading. We will determine the nature of structure, degree of crystallinity, grain size, and transformation mechanisms under a range of loading conditions. We will then extend our study to a wider range of oxides and silicates of geological importance. The results of our work will be used to develop a deeper understanding of how geological materials response to fast impulsive loading.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- May 26, 2016
- Source ID
- HDTRA11510048
Entities
People
- Thomas S Duffy
Organizations
- Defense Threat Reduction Agency
- Princeton University