Mean-force scattering potential for calculating optical properties of dense plasmas

Journal Article · 01 February 2019 · High Energy Density Physics

DOI: https://doi.org/10.1016/j.hedp.2019.02.001 · OSTI ID:1494479

Gill, Nathanael Matthew  ^[1]; Starrett, Charles Edward  ^[2]

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1. Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Auburn Univ., Auburn, AL (United States)
2. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

Here, we assess the relative importance of ionic structure on the opacity of dense plasmas by using the potential of mean force as a scattering potential within the Kubo-Greenwood formalism. We compare results from the potential of mean force, which includes realistic ionic structure, to results using an average atom potential, which includes only a crude treatment of ionic structure. Comparisons with less approximate but more expensive DFT-MD simulations for aluminum plasma reveal that the mean force generally improves agreement for DC conductivity. We also see improvement when applying the mean force to free-free transitions, whereas for bound-bound and bound-free transitions the mean force leads to poorer agreement on transition energies. Further, we assess the impact of accounting for correlations within the plasma at the temperature and density conditions relevant to iron opacity measurements at Sandia’s Z machine facility and find that these correlations do not account for the discrepancy between the measurements and leading opacity calculations.

• Research Organization: Los Alamos National Laboratory (LANL)
• Sponsoring Organization: USDOE
• Grant/Contract Number: 89233218CNA000001
• OSTI ID: 1494479
• Report Number(s): LA-UR-18-27960
• Journal Information: High Energy Density Physics, Journal Name: High Energy Density Physics Journal Issue: C Vol. 31; ISSN 1574-1818
• Publisher: ElsevierCopyright Statement
• Country of Publication: United States
• Language: English