Development of a hybrid atomic model for application to the suite of numerical radiation magnetohydrodynamic and spectroscopic tools at NRL

We present on progress made to the development of a hybrid structure atomic model for application to the suite of NRL numerical radiation magnetohydrodynamic (RMHD) and spectroscopic codes. Current multi-physics simulations at NRL, such as MACH2-TCRE and DZAPP, employ atomic models with either limited detailed configuration structure or ground-to-ground approximations for two-electron processes which constrain the accuracy of equation-of-state calculations for RMHD modeling and predictive capabilities of high-fidelity spectroscopic modeling. The hybrid structure atomic model improves on the current implementation with a combination of detailed, fine-structure configurations for diagnostically-important resonance lines from the central charge states and compressed, configuration-averaged accounting for level structure and coupling completeness of satellite features from the neighboring, off-center charge states. Coupled collisional-radiative rate equations are solved for non-local thermodynamic equilibrium level populations and compared to alternative theoretical models by way of average ionization, desired equation-of-state parameters, and relative intensities of diagnostically-valuable Ar emission lines. The potential impact of a hybrid atomic model on RMHD simulations at NRL will be discussed in the context of future work.



This work is supported by the NRL Karle’s Fellowship.



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