Modeling Plasma Kinetic Effects in ICF Targets

Inertial Confinement Fusion (ICF) targets consist of multiple materials. During target compression, these materials undergo significant acceleration causing these materials to mix. Direct Numerical Simulations (DNS) of whole targets are prohibitively expensive due to the 3-Dimensional (3D) nature of the flow and initially low fluid viscosity. Therefore, ICF targets are modelled using inviscid Euler equations coupled with sub-grid closure mix models and with other models for relevant physics such as heat transport. We compare the results of Los Alamos National Laboratory (LANL) mix models denoted BHR and LWN to DNS of the Deceleration Rayleigh-Taylor Instability (DRTI) between a Carbon ablator and Deuterium fuel inside an ICF target. DRTI occurs around the time of targets maximal compression resulting in mixing of hot plasmas when kinetic effects on mixing are significant. These kinetic effects are directly accounted for in LANL hydrodynamic code xRAGE and therefore xRAGE is used to run DNS of DRTI. We demonstrate that the significance of plasma kinetic effects is underestimated in 2D simulations compared to 3D simulations. Next, we show how to account for plasma kinetic effects in LANL mix models. The LWN mix model is particularly suitable for such accounting.