Diagnosing and controlling mix in NIF implosion experiments

POSTER

Abstract

High mode number instability growth of ``isolated defects'' on the surfaces of NIF capsules can be large enough for the perturbation to penetrate the imploding shell and produce a jet of ablator material that enters the hot-spot. Since internal regions of the CH ablator are doped with Ge, mixing of this material into the hot-spot results in a clear signature of Ge K-shell emission. Evidence of jets entering the hot-spot has been recorded in x-ray images and spectra, consistent with simulation predictions.\footnote{B. A. Hammel, et al, High Energy Density Physics \textbf{- 6} (- 2) (2010). Prepared by LLNL under Contract DE-AC52-07NA27344.} Ignition targets have been designed to minimize instability growth, and capsule fabrication improvements are underway to reduce ``isolated defects.'' An experimental strategy has been developed where the final requirements for ignition targets can be adjusted through direct measurements of mix and experimental tuning.

Authors

  • B. Hammmel

    Lawrence Livermore National Laboratory

  • H.A. Scott

    Lawrence Livermore National Laboratory

  • M.A. Barrios

    Lawrence Livermore National Laboratory

  • C. Cerjan

    Lawrence Livermore National Laboratory

  • D. Clark

    Lawrence Livermore National Laboratory, LLNL

  • M.J. Edwards

    Lawrence Livermore National Laboratory, LLNL

  • Siegfried Glenzer

    LLNL, Lawrence Livermore National Laboratory, Lawrence Livermore National Lab

  • S.W. Haan

    Lawrence Livermore National Laboratory, Lawrence Livermore National Lab

  • N. Izumi

    Lawrence Livermore National Laboratory, Lawrence Livermore National Labl, Lawrence Livermore National Lab.

  • J.A. Koch

    Lawrence Livermore National Laboratory

  • O. Landen

    Lawrence Livermore National Laboratory, LLNL, Lawrence Livermore National Lab

  • T. Ma

    Lawrence Livermore National Laboratory, Lawrence Livermore National Lab

  • L. Suter

    Lawrence Livermore National Laboratory, Lawrence Livermore National Lab

  • S.P. Regan

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

  • R. Epstein

    University of Rochester

  • G. Kyrala

    Los Alamos National Laboratory, Lawrence Livermore National Laboratory, LANL

  • K. Peterson

    Sandia National Laboratories, Albuquerque, NM 87185, USA, Sandia National Labs, Sandia National Laboratories