Kinetic Effects in Cryogenic ICF Implosions: A Comparison of Hydrodynamic and Fokker-Planck Simulations

Most inertial confinement fusion (ICF) simulations use the fluid approximation to model implosion dynamics. While efficient, this assumes electrons and ions have Maxwellian distributions—an assumption that breaks down in kinetic regimes when the plasma's mean free path is comparable to plasma gradient scale lengths. In these cases, a kinetic treatment is crucial for modeling phenomena like species and temperature separation. This study focuses on ion kinetic effects, beginning at shock breakout into the gas layer during cryogenic ICF implosions on the OMEGA laser. We use a one-dimensional Fokker-Planck code (iFP), developed by W.T. Taitano et al., J. Comp. Phys., 263, 10786 (2021). By comparing iFP to LILAC, we identify discrepancies between fluid and kinetic treatments and quantify their potential impact on OMEGA experiments.