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Absorption Measurements Validate the Langdon Factor and Discriminate Between Coulomb Logarithms

ORAL

Abstract

Inverse-bremsstrahlung absorption was measured based on transmission through a finite-length plasma that was well characterized using imaging Thomson scattering. Expected absorption was calculated using the diagnosed plasma conditions while varying the Coulomb logarithm treatment and the use of the Langdon absorption-reduction factor. The experimental data are well reproduced only when using both the Langdon factor and the Johnston-Dawson Coulomb logarithm. The Lee-More Coulomb logarithm—which is widely used in radiation-hydrodynamics codes to simulate inertial confinement fusion implosions—predicts almost 50% more absorption than was observed.

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Publication: D. Turnbull et al., "Absorption Measurements Validate the Langdon Factor and Discriminate Between Coulomb Logarithms," in preparation to be submitted to Physical Review Letters.

Presenters

  • David Turnbull

    University of Rochester, Laboratory for Laser Energetics, University of Rochester

Authors

  • David Turnbull

    University of Rochester, Laboratory for Laser Energetics, University of Rochester

  • Joseph D Katz

    University of Rochester - Laboratory for Laser Energetics, University of Rochester Laboratory for Laser Energetics, Laboratory for Laser Energetics, University of Rochester, Laboratory for Laser Energetics, University of Rochester

  • Avram L Milder

    University of Alberta

  • Mark Sherlock

    Lawrence Livermore Natl Lab

  • David J Strozzi

    Lawrence Livermore Natl Lab, LLNL

  • William Armstrong

    University of Rochester Laboratory for Laser Energetics

  • Laurent Divol

    Lawrence Livermore Natl Lab, LLNL

  • Dana H Edgell

    LLE, Laboratory for Laser Energetics, University of Rochester

  • Russell K Follett

    Laboratory for Laser Energetics - Rochester, Laboratory for Laser Energetics, University of Rochester

  • Suxing Hu

    Laboratory for Laser Energetics, University of Rochester, LLE, University of Rochester, Lab. for Laser Energetics, U. of Rochester

  • Pierre A Michel

    Lawrence Livermore National Laboratory, Livermore CA 94550, Lawrence Livermore National Laboratory, Lawrence Livermore Natl Lab

  • Dustin Froula

    University of Rochester, Laboratory for Laser Energetics, Laboratory for Laser Energetics, U. of Rochester, Laboratory for Laser Energetics, University of Rochester