A non-LTE model for spectroscopy based on self-consistent average-atom orbitals*

High energy density experiments and simulations rely on understanding the material properties of matter at extreme conditions. These include equations of state (EOS), transport coefficients, and radiative properties such as opacities and emissivities. Radiative properties are typically calculated by specialized multi-configuration codes that are based on data for isolated atoms, and which are thus not explicitly consistent with the density-functional-theory (DFT) codes typically used to generate high-quality EOS and transport data. Here, we show that self-consistent orbitals from a DFT-based average atom code can be used to build multiconfiguration atomic structure [1] suitable for collisional-radiative modeling, thereby extending the functionality of DFT-based models to non-LTE conditions and increasing the consistency of opacity and emissivity calculations with EOS and transport tables based on DFT models. The detailed non-LTE emission and absorption spectra produced by this model natively account for plasma density effects such as continuum lowering and is compared with spectra from the widely used Spectroscopic Collisional-Radiative Atomic Model (SCRAM) [2].

 

[1] G. Faussurier, Phys Rev E 97, 023206 (2018).

[2] S.B. Hansen, J. Bauche, C. Bauche-Arnoult, and M.F. Gu, HEDP 3, 109 (2007).