Spatially resolved x-ray fluorescence spectroscopy of beryllium capsule implosions at the NIF

ORAL

Abstract

Beryllium ablators used in indirectly driven inertial confinement fusion implosions are doped with copper to prevent preheat of the cryogenic hydrogen fuel. Here, we present analysis of spatially resolved copper K-$\alpha$ fluorescence spectra from the beryllium ablator layer. It has been shown that K-$\alpha$ fluorescence spectroscopy can be used to measure plasma conditions of partially ionized dopants in high energy density systems [1]. In these experiments, K-shell vacancies in the copper dopant are created by the hotspot emission at stagnation, resulting in K-shell fluorescence at bang time. Spatially resolved copper K-$\alpha$ emission spectra are compared to atomic kinetics and radiation code simulations to infer density and temperature profiles. [1] M. J. MacDonald et al, J. Appl. Phys. 120, 125901 (2016).

*This work was supported by the US DOE under grant No. DE-NA0001859, under the auspices of the US DOE by Lawrence Livermore National Laboratory under Contract No. DE-AC52-07NA27344, and by Los Alamos National Laboratory under contract DE-AC52-06NA52396.

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Authors

  • M. J. MacDonald

    • University of California, Berkeley
    • University of California - Berkeley

  • D. T. Bishel

    • Lawrence Livermore National Laboratory

  • A. M. Saunders

    • University of California, Berkeley

  • H. A. Scott

    • Lawrence Livermore National Laboratory

  • G. Kyrala

    • Los Alamos National Laboratory

  • J. Kline

    • Los Alamos National Laboratory

  • S. MacLaren

    • Lawrence Livermore National Laboratory

  • D. B. Thorn

    • Lawrence Livermore National Laboratory

  • S. A. Yi

    • Los Alamos National Laboratory

  • A. B. Zylstra

    • Los Alamos National Laboratory

  • R. W. Falcone

    • University of California, Berkeley

  • T. Doeppner

    • Lawrence Livermore National Laboratory