Study of Discrepancies in Deuterium Sound Speed Near 200 GPa*

Accurately modeling the Equation of State (EOS) for hydrogen and its isotopes is crucial for understanding fundamental processes in Inertial Confinement Fusion (ICF) and astrophysical phenomena. In a recent study, D. E. Fratanduono et al. identified discrepancies in the sound speed of deuterium at pressures around 200 GPa, revealing limitations in current modeling capabilities. In this work, we show the design of experiments aimed at measuring deuterium's sound speed on the OMEGA 60 laser system to verify and investigate this anomaly. Additionally, we discuss the theoretical basis, suggesting that the electrostatic acoustic mode could underlie this discrepancy. To support this study, we present preliminary results from large-scale Particle-in-Cell (PIC) simulations of ion-acoustic waves.