Knock-on Deuteron Imaging of the Hot Spot and Compressed Fuel in Direct-Drive Cryogenic ICF Implosions

ORAL

Abstract

Neutrons from D-T fusion reactions in the hot spot of inertial confinement fusion (ICF) implosions elastically scatter deuterons and tritons as they transit the surrounding dense fuel layer. The energy of these ``knock-on'' charged particles depends on their angle of scattering and ranges up to 12.5 (10.6) MeV for deuterons (tritons), respectively. The most-energetic particles are forward scattered and indicate the shape of the hot spot, whereas lower-energy particles are made by sidescattering and ranging in the fuel and contain information about the distribution of mass around the hot spot. We report on the design and first results of a knock-on deuteron imager (KoDI) to record spectrally resolved images of these scattered particles from laser-direct-drive cryogenic ICF implosions on the OMEGA laser. The source is imaged using a multi-penumbral aperture with 35\texttimes magnification. A CR-39 detector provides energy resolution in the resulting images, from which the symmetry of the hot spot and of areal density in the hemisphere of the converged fuel layer facing the camera are inferred. Image plates record a co-aligned \textgreater 10 keV x-ray image of the implosion using the same aperture. Results from OMEGA cryogenic implosions are presented.

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Authors

  • Hans Rinderknecht

    Laboratory for Laser Energetics, LLE-UR, LLE

  • James Knauer

    Laboratory for Laser Energetics, U. of Rochester, 4Laboratory for Laser Energetics, Laboratory for Laser Energetics, LLE-UR, University of Rochester, Lab for Laser Energetics

  • P. B. Radha

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

  • Sean Regan

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

  • J. Kunimune

    Massachusetts Institute of Technology, PSFC-MIT

  • P. Adrian

    PSFC, MIT, Massachusetts Institute of Technology MIT, Massachusetts Institute of Technology, PSFC-MIT

  • Johan Frenje

    MIT, PSFC, MIT, Massachusetts Institute of Technology, PSFC-MIT

  • Maria Gatu-Johnson

    MIT, Massachusetts Institute of Technology, PSFC-MIT

  • F.H. Seguin

    Massachusetts Institute of Technology, PSFC-MIT

  • B. Bachmann

    Lawrence Livermore Natl Lab, Lawrence Livermore National Laboratory, LLNL