First-principles calculations of stopping powers in fusion-relevant mixtures*

During implosion of fusion capsules, instabilities at material interfaces can lead to mixing that impacts transport of fusion products through the fuel. Accurately predicting fusion yields and designing experiments accordingly therefore relies on accurate models of stopping powers in high energy density mixtures. Here, we calculate proton stopping powers in warm dense deuterium, carbon, and a deuterium-carbon mixture using real-time time-dependent density functional theory. First, we extend a recently developed method for selecting a single, representative projectile trajectory that reduces the need for averaging over multiple calculations to heterogeneous systems. Then, we investigate the validity of Bragg's rule of additivity and benchmark average atom and dielectric function approaches for this system. These efforts lay the foundation for further research on interface and mixing effects on stopping power in warm dense matter.