Bremsstrahlung Emission and Absorption in Strongly Coupled Plasmas

Bremsstrahlung emission and absorption are important mechanisms for radiation transport in the plasmas found in red dwarf stars and inertial confinement fusion experiments. The plasmas in these applications are often in the strongly coupled regime, where the average potential energy exceeds the average kinetic energy. This work presents mean force emission theory, a reduced model that extends classical bremsstrahlung theory to strongly coupled plasmas, and benchmarks the theory against first principles classical molecular dynamics (MD) simulations. The theory agrees well with MD simulations of both repulsively and attractively interacting plasmas. Furthermore, we show that near the electron plasma frequency, static screening lowers bremsstrahlung absorption while strong, time-dependent correlations enhance it. These effects are especially important for inertial confinement fusion experiments, where much of the laser energy is deposited in a target near the critical density.