An Assessment of Laser-Plasma Instabilities in NIF Ignition Hohlraums with Different Capsule Ablators.

ORAL

Abstract

The NIF ignition point design uses a cryogenic DT fuel enclosed within a copper-doped beryllium ablator. The capsule is placed in a gold-uranium cocktail hohlraum driven to a peak drive temperature of 285eV. As part of a system optimization study we are examining two alternative ablator materials: high-density carbon, and germanium-doped plastic. High-density carbon, for a given capsule size, absorbs most x-ray energy. Changing the ablator material alters the plasma conditions inside the hohlraum, consequently modifying the laser-plasma interactions (LPI). We report on LASNEX simulations of hohlraums with these three ablator materials, quantifying the bulk plasma conditions, and use them to estimate the relative risk for LPI.

*This work was performed under the auspices of the U.S. Department of Energy by the University of California, Lawrence Livermore National Laboratory under contract No. W-7405-Eng-48.

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Authors

  • R.P.J. Town

    • Lawrence Livermore National Laboratory

  • D.A. Callahan

  • L. Divol

  • M.J. Edwards

  • S.W. Haan

  • D.E. Hinkel

  • D.D. Ho

  • O.S. Jones

  • P. Michel

  • L.J. Suter

  • E.A. Williams

    • Lawrence Livermore National Laboratory, Livermore, CA