Analysis of the First NIF Neutron Images

ORAL

Abstract

Neutron imaging at the National Igntion Facility obtained its first images from both directly laser driven and X-radiation driven implosions. A directly driven DT filled glass microballoon gave an oblate image (P2/P0=-45{\%}) whose size (P0=70$\mu $m) fit within the X-ray images. Simulations using the polar direct drive laser pointing give a round image of P0 $\sim $95$\mu $m. However as the electron flux limiter is reduced from 0.06 to 0.03 the image becomes oblate. The observed asymmetry can be reproduced by transferring $\sim $10{\%} of the energy from the outer laser beams to the inner. Radiation driven implosions of ignition capsules with 20{\%}D, and 50{\%}D produced $\sim $ 30$\mu $m radius oblate images in 12-15 MeV neutrons. Images in 10-12 MeV neutrons, which have experienced one scattering in the fuel and number $\sim $ 4{\%} of the primaries, showed larger images ($\sim $44-56 $\mu $m). Image sizes indicate the compression of the fuel and are consistent with observed 10-12/13-15MeV yield ratios. Work funded by the USDOE at LANL, LLNL, NSTEC and LLE.

Authors

  • D.C. Wilson

    • LANL
    • Los Alamos National Laboratory
  • S. Batha

    • LANL
    • Los Alamos National Laboratory
  • G.P. Grim

    • Los Alamos National Laboratory
  • N. Guler

    • LANL
    • Los Alamos National Laboratory
  • J.L. Kline

    • Los Alamos National Laboratory
    • LANL
  • G.A. Kyrala

    • Los Alamos National Laboratory
  • F.E. Merrill

    • LANL
    • Los Alamos National Laboratory
  • G.L. Morgan

    • Los Alamos National Laboratory
  • N.S. Vinyard

    • Los Alamos National Lab
    • Los Alamos National Laboratory
    • LANL
  • P.L. Volegov

    • LANL
    • Los Alamos National Laboratory
  • D.K. Bradley

    • LLNL
    • Lawrence Livermore National Laboratory
    • Lawrence Livermore National Lab
  • D. Clark

    • Lawrence Livermore National Laboratory
    • LLNL
  • S.N. Dixit

    • Lawrence Livermore National Laboratory
    • Lawrence Livermore National Lab
  • D.N. Fittinghoff

    • Livermore National Laboratory
    • Lawrence Livermore National Laboratory
  • S.M. Glenn

    • Lawrence Livermore National Laboratory
  • Siegfried Glenzer

    • LLNL
    • Lawrence Livermore National Laboratory
    • Lawrence Livermore National Lab
  • N. Izumi

    • Lawrence Livermore National Laboratory
    • Lawrence Livermore National Labl
    • Lawrence Livermore National Lab.
  • O. Jones

    • Lawrence Livermore National Laboratory
    • LLNL
  • S. Le Pape

    • Lawrence Livermore National Laboratory
    • LLNL
  • T. Ma

    • Lawrence Livermore National Laboratory
    • Lawrence Livermore National Lab
  • A.J. Mackinnon

    • Lawrence Livermore National Laboratory
    • LLNL
  • S.M. Sepke

    • Lawrence Livermore National Laboratory
  • Brian Spears

    • LLNL
    • Lawrence Livermore National Laboratory
  • R. Tommasini

    • Lawrence Livermore National Laboratory
  • P. McKenty

    • Laboratory for Laser Energetics