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Hydrodynamic scaling and hot electron preheat in NIF and OMEGA direct-drive ICF implosions

ORAL

Abstract

Hydrodynamic scaling of direct-drive ICF implosion properties and hot electron preheat, which may degrade compression, have been studied at different scales in polar direct drive (PDD) experiments on the National Ignition Facility (NIF) and OMEGA. Hard x-ray emission from buried Ge-doped layers was measured in NIF implosions of 2.3 mm CH shells at 730 kJ laser energy to infer ~0.2% of laser energy deposited as hot-electron preheat in the inner ~80% of the unablated shell at an intensity of 1015 W/cm2, close to the tolerable level of preheat in direct-drive ignition designs. Hydrodynamically equivalent implosions on OMEGA at 3.4 times smaller scale (40 times less laser energy) show similar levels of preheat and implosion trajectories that approximately follow the expected hydrodynamic scaling. These results support the hydrodynamic scaling of warm target implosions between OMEGA and NIF scales. To aid extrapolation of these results to direct-drive ignition designs, additional experiments were conducted on NIF at the 3-mm, 1.5-MJ scale. Hot electron preheat and implosion energetics from these ignition-scale experiments will be discussed.

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Publication: M. J. Rosenberg et al. "Hot Electron Preheat in Hydrodynamically Scaled Direct-Drive Inertial Confinement Fusion Implosions on the NIF and OMEGA" (to be submitted)

Presenters

  • Michael J Rosenberg

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

Authors

  • Michael J Rosenberg

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

  • Andrey Solodov

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

  • Alison R Christopherson

    Lawrence Livermore National Laboratory, LLNL

  • Riccardo Betti

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

  • Radha Bahukutumbi

    University of Rochester

  • Christian Stoeckl

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

  • Matthias Hohenberger

    Lawrence Livermore Natl Lab

  • Benjamin Bachmann

    Lawrence Livermore Natl Lab

  • Pierre A Michel

    Lawrence Livermore National Laboratory, Livermore CA 94550, Lawrence Livermore National Laboratory, Lawrence Livermore Natl Lab

  • Gareth N Hall

    Lawrence Livermore Natl Lab

  • Steven Kostick

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

  • Chad J Forrest

    Lab for Laser Energetics, University of Rochester

  • Vladimir Y Glebov

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

  • Frederic J Marshall

    University of Rochester

  • Christine M Krauland

    General Atomics

  • Timothy J Collins

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

  • Valeri N Goncharov

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

  • Wolfgang R Theobald

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

  • Sean P Regan

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