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Oxygen Opacity Measurements at Solar Interior Conditions on the National Ignition Facility

ORAL

Abstract

The location of the Sun’s convection zone boundary (CZB) is precisely inferred by helioseismic measurements, but solar models predict a significantly shallower depth1. One hypothesis is that opacity models underpredict the true radiative opacity of the solar mixture at CZB conditions. If true, this could also affect theoretical cooling rates for white dwarfs (WDs), which are used as chronometers for stellar populations like the disk of the Milky Way2. Oxygen contributes the largest fraction to the opacity near the Sun’s CZB and makes up approximately half the composition of an average WD. Measurements of oxygen opacity near solar CZB conditions are underway at the National Ignition Facility (NIF). Recent advancements in the analysis of these experiments and future oxygen opacity experiments on the NIF are presented.



[1] Basu & Antia, Phys. Rep. (2008)

[2] Saumon et al., Phys. Rep. (2022)

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Publication: Mayes, D. C., Hobbs, B. A., Heeter, R. F. et al., HEDP (2025)<br>Hobbs, B. A., Mayes, D. C., Heeter, R. F. et al. Rev. Sci. Instrum. (2024)

Presenters

  • Bryce Hobbs

    University of Texas at Austin

Authors

  • Bryce Hobbs

    University of Texas at Austin

  • Daniel C Mayes

    University of Texas at Austin

  • Robert F Heeter

    Lawrence Livermore National Laboratory

  • Paul A Bradley

    Los Alamos National Laboratory (LANL)

  • Christopher J Fontes

    Los Alamos National Laboratory (LANL)

  • Matthias Hohenberger

    Lawrence Livermore National Laboratory

  • Heather M Johns

    Los Alamos National Laboratory (LANL)

  • Yekaterina P Opachich

    Lawrence Livermore National Laboratory, Lawrence Livermore National Lab

  • Harry Francis Robey

    Los Alamos National Laboratory (LANL)

  • Stanislav Stoupin

    Lawrence Livermore National Laboratory

  • Matthew S Wallace

    Nevada National Security Sites

  • Michael Houston Montgomery

    University of Texas at Austin

  • Theodore S Perry

    Los Alamos National Laboratory (LANL)

  • Don E Winget

    University of Texas at Austin, The University of Texas at Austin