The Equation of State of Al<sub>2</sub>O<sub>3</sub>: Dynamic Compression in Terapascal and kilo Kelvin Conditions
ORAL
Abstract
Sapphire, known for its remarkable incompressibility at ambient conditions, plays a pivotal role in both static and dynamic compression research. Accurately characterizing its equation of state (EoS) is essential for these applications. We present a complete Hugoniot of Al2O3 as locus of experimentally assessed, high-precision, pressure, density and temperature states up to 1.4 TPa and 43 kK. The Hugoniot is established using magnetically launched hyper velocity flyers on the Z Accelerator at SNL. Our findings indicate a significant deviation from existing tabular Al2O3 EoS models, dictating a comprehensive overhaul. We develop two advanced EoSs for Al2O3: the SESAME 97412 model, featuring an extensive phase diagram, with three solid phases and the liquid phase, as well as the updated LEOS 2200m2 model. Accurate experimental determination of extreme pressures and temperatures, paired with sophisticated models, advances the frontier of EoS development beyond 1 terapascal.
*SAND2025-01336A. SNL is managed by NTESS, LLC under contract DE-NA0003525.LANL is operated by Triad National Security, LLC, for the National Nuclear Security Administration of the U.S. Department of Energy under contract 89233218NCA000001.LLNL is operated under contract No. DE-762AC52-07NA27344.This work describes objective technical results and analysis. Any subjective views or opinions that might be expressed in the work do not necessarily represent the views of the U.S. Department of Energy or the United States Government.
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Presenters
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Pat Kalita
- Sandia National Laboratories