The Evolution of the Gold Bubble in NIF Ignition Gas-Filled Hohlraums

ORAL

Abstract

At the National Ignition Facility (NIF), the energy from 192 laser beams is converted to an x-ray drive in a gas-filled gold hohlraum. The x-ray drive heats and implodes a fuel capsule. The ViewFactor platform uses a truncated hohlraum to measure the x-ray drive from the capsule point-of-view. This platform also affords excellent diagnostic views of the hohlraum interior, in particular, of the region in which the outer beams deposit their energy (the ``gold bubble'') Time-resolved and time-integrated images in the hard x-ray range (\textgreater 3 keV) reveal an 8-fold symmetry in the gold bubble. The Au plasma in the bubble from the eight 50 degree quads expands faster than that from the interleaved 44.5 degree quads. The variation in this structure with laser intensity, with pulse shape and cross beam energy transfer, and comparison to models, will be discussed.

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Authors

  • M.B. Schneider

    Lawrence Livermore Natl Lab, Lawrence Livermore National Laboratory

  • S. MacLaren

    Lawrence Livermore Natl Lab, Lawrence Livermore National Laboratory, LLNL

  • Klaus Widmann

    Lawrence Livermore Natl Lab

  • N. Meezan

    Lawrence Livermore National Laboratory, Lawrence Livermore Natl Lab, LLNL

  • Jim Hammer

    Lawrence Livermore Natl Lab, Lawrence Livermore National Laboratory, LLNL

  • Perry Bell

    Lawrence Livermore Natl Lab

  • Robin Benedetti

    Lawrence Livermore Natl Lab

  • David Bradley

    Lawrence Livermore Natl Lab

  • D. Callahan

    Lawrence Livermore Natl Lab, LLNL, Lawrence Livermore National Laboartory

  • E.L. Dewald

    Lawrence Livermore National Laboratory, Lawrence Livermore Natl Lab

  • Tilo Doeppner

    Lawrence Livermore Natl Lab

  • D.E. Hinkel

    Lawrence Livermore Natl Lab, LLNL, Lawrence Livermore National Laboratory

  • Oggie Jones

    Lawrence Livermore Natl Lab, LLNL

  • O. L. Landen

    Lawrence Livermore Natl Lab, LLNL

  • Pierre Michel

    Lawrence Livermore National Laboratory, Lawrence Livermore Natl Lab, LLNL

  • J.L. Milovich

    Lawrence Livermore National Laboratory, Lawrence Livermore Natl Lab, LLNL

  • John Moody

    Lawrence Livermore National Laboratory, Lawrence Livermore Natl Lab, LLNL

  • Alastair Moore

    Lawrence Livermore Natl Lab