Crystalline/Molecular Mechanisms Governing Structural and Chemical Changes in Shocked HE Single Crystals Real-Time, Multiscale Measurements
Abstract
The ability to credibly predict shock wave induced chemical decomposition in high explosives (HE) and the resulting shock to detonation transition (SDT) is a long-standing and important need regarding the optimal design and use of high explosives for DoD applications: high performance (energy release) to address mission needs and requisite insensitivity to ensure energy release onlywhen desired. Toward this objective, a three year research effort is proposed to examine and understand the fundamental crystalline/molecular mechanisms that govern shock wave induced chemical decomposition of HE crystals. To gain the desired mechanistic insights, our proposed effort will focus on, and integrate, the following key elements: plane shock wave experiments;use of HE single crystals; and real-time, multiscale measurements during shock compression.An important objective of our research effort will be to understand the linkage between shock induced physical changes (microstructural changes due to elastic-plastic deformation and/or structural transformations) and chemical decomposition. Understanding this linkage is essential for credible multiscale modeling/simulations. However, experimental measurements to examineand understand this linkage constitute a significant challenge. To bridge the current length scale gap between continuum measurements (wave profiles) and molecular changes (electronic and vibrational spectroscopy), we propose to undertake real-time x-ray diffraction (XRD) measurements during the shock compression of HE single crystals. New experimental capabilities~ the Dynamic Compression Sector (DCS) at the Advanced Photon Source (APS), Argonne National Laboratory ~ have made it possible to obtain XRD measurements to examine microstructural changes during shock wave induced elastic-plastic deformation and structural transformations. Research activities at the DCS, and resulting publications, have demonstrated that the desired microscale measurements can be obtained during shock compression/release in a wide range of non-energetic, single crystals and polycrystals. Hence, extending the use of the DCS capabilities to shock compression of HE single crystals is indeed timely.Use of the unique DCS capabilities to obtain real-time microscopic measurements in shocked HE single crystals is the principal thrust of the proposed research activities. We acknowledge the significant scientific and technical challenges associated with the proposed experimental effort andits implementation at a national user facility. However, the potential payoff ~ the ability to link the shock wave response of HE single crystals across the length scales of interest ~ is significant and makes a strong case for undertaking the proposed experiments.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jan 23, 2019
- Source ID
- N000141912047
Entities
People
- Yogendra Gupta
Organizations
- Office of Naval Research
- United States Navy
- Washington State University