Modeling asymmetric cavity collapse with plasma equations of state.
We explore the effect that equation of state (EOS) thermodynamics has on shock-driven cavity-collapse processes. We account for full, multidimensional, unsteady hydrodynamics and incorporate a range of relevant EOSs (polytropic, QEOS-type, and SESAME). In doing so, we show that simplified analytic EOSs, like ideal gas, capture certain critical parameters of the collapse such as velocity of the main transverse jet and pressure at jet strike, while also providing a good representation of overall trends. However, more sophisticated EOSs yield different and more relevant estimates of temperature and density, especially for higher incident shock strengths. We model incident shocks ranging from 0.1 to 1000 GPa, the latter being of interest in investigating the warm dense matter regime for which experimental and theoretical EOS data are difficult to obtain. At certain shock strengths, there is a factor of two difference in predicted density between QEOS-type and SESAME EOS, indicating cavity collapse as an experimental method for exploring EOS in this range.
First Light Fusion Ltd., Begbroke Science Park, OX5 1PF, United Kingdom and Department of Engineering Science, University of Oxford, OX1 3PJ, United Kingdom.
Brett
B
Tully
First Light Fusion Ltd., Begbroke Science Park, OX5 1PF, United Kingdom and Department of Engineering Science, University of Oxford, OX1 3PJ, United Kingdom.
Nicholas
N
Hawker
Department of Mechanical Engineering, University College London, Torrington Place, Cordon, WC1E 7JE, United Kingdom.
Yiannis
Y
Ventikos