Nonlocal non-Maxwellian electron distributions in radiating laser-plasmas*

At laser irradiances relevant to ICF, steep temperature gradients lead to nonlocal electron thermal transport. The electron heat flux from the nonlocal anisotropy f₁ of the electron distribution function (EDF) alters the self-emission from the laser-heated plasma. This deviation of f₁ from classical to nonlocal is caused by the deviation of the isotropic component of the EDF, f₀, from Maxwellian. Consequently, this work considers both the nonlocal heat flux from f₁ and the non-Maxwellian distortion from f₀ on the plasma’s self-emission.

 

HYDRA radiation-hydrodynamics simulations are performed utilizing the Schurtz-Nicolai-Busquet (SNB) nonlocal transport model. Kinetic EDFs from HYDRA plasma conditions are calculated with the Vlasov-Fokker-Planck code K2. Nonlocal, non-Maxwellian emissivities and radiative fluxes are then calculated with CRETIN. These studies find that the non-Maxwellian f₀ affects the emissivity of plasma states in the laser-ablation front. In addition, the effect of other sources of non-Maxwellian distributions in laser-plasmas are assessed.