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Laser-Direct-Drive Energy Coupling at 4×10<sup>14</sup> W/cm<sup>2</sup> to 1.2×10<sup>15</sup> W/cm<sup>2</sup> from Spherical Solid Plastic Implosions at the National Ignition Facility

ORAL

Abstract

Laser-direct-drive energy-coupling experiments are being conducted at the National Ignition Facility (NIF) using a spherical, solid plastic target with a diameter of 2.1 mm. The targets are irradiated with 184 NIF laser beams in a polar-direct-drive (PDD) geometry. A series of shots was performed by varying the peak intensity in the range of 4×1014 W/cm2 to 1.2×1015 W/cm2 with a 7-ns-long shaped pulse. The trajectory of the spherically converging shock wave was recorded using ~100-ps gated, x-ray backlighting at 8.4 keV. In addition, the arrival time of the shock in the center of the sphere was measured from the x-ray flash created by the shock collapse with gated x-ray imagers. Solid spheres offer the advantage for quantifying energy coupling without the challenges from hydrodynamic instabilities of imploding shells. Good agreement is obtained of the measured shock trajectories with the trajectories from 2-D radiation-hydrodynamics simulations from the DRACO code using CBET and nonlocal heat-transport models. Similar experiments have been performed on OMEGA (configured for PDD) with an energy of 13 kJ to test the scaling arguments of PDD implosions from OMEGA to NIF energies.

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Presenters

  • Wolfgang R Theobald

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

Authors

  • Wolfgang R Theobald

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

  • Michael J Rosenberg

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

  • Radha B Bahukutumbi

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

  • Sean P Regan

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

  • Christian Stoeckl

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

  • Riccardo Betti

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

  • Kenneth Anderson

    Lab for Laser Energetics, University of Rochester

  • John A Marozas

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

  • Valeri N Goncharov

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

  • Edward M Campbell

    University of Rochester

  • Claudia M Shuldberg

    General Atomics

  • Rain W Luo

    General Atomics

  • Wendi Sweet

    General Atomics

  • David N Kaczala

    General Atomics

  • Benjamin Bachmann

    Lawrence Livermore Natl Lab, LLNL

  • Tilo Doeppner

    Lawrence Livermore National Laboratory, Lawrence Livermore Natl Lab

  • Matthias Hohenberger

    Lawrence Livermore Natl Lab, LLNL

  • Robbie H Scott

    Rutherford Appleton Laboratory, STFC Rutherford Appleton Laboratory, Rutherford Appleton Lab, Central Laser Facility, RAL, STFC, Central Laser Facility

  • Arnaud Colaïtis

    CELIA, Centre Lasers Intenses et Applications, University of Bordeaux