Grüneisen Parameter Determination from Shock Wave Experiments: Assumptions and Requirements*

Although the Mie-Grüneisen equation of state (EOS) – a particular form of the E(P,V) representation – is not a thermodynamically complete EOS, it is widely used to model the material response in shock wave studies. Because the combination of isentropic sound speed in the shock compressed states and knowledge of the Hugoniot curve constitutes the information needed to calculate the Grüneisen parameter (Γ), sound speed measurements in the shocked state provide a convenient approach to experimentally determine Γ at high pressures and temperatures. The assumptions and challenges related to the experimental determination of Γ, using this approach, will be presented. Results from recent publications on shock-induced solid/liquid transition in soda lime glass (PRB, 2021), silver (PRB, 2021), and LiF (PRB, 2023) will be utilized to discuss the requirements for determination of Γ from sound speed measurements in shock wave experiments.