Measurements of the Conduction-Zone Length and Mass Ablation Rate to Study the Hydrodynamic Coupling in Cryogenic Direct-Drive Implosions on OMEGA

ORAL

Abstract

The ablation-front trajectory and the averaged mass ablation rate is measured in direct-drive cryogenic target implosions on the OMEGA Laser System by imaging the soft x rays emitted by the coronal plasma. The length of the conduction zone is determined by coupling x-ray and scattered-light measurements. These measurements are compared to hydrodynamic simulations to study the modeling of the hydrodynamic coupling for various beam and target radii. Reducing the beam focal-spot radius relative to the target radius is a method that is being studied to reduce cross-beam energy transfer and increase the hydrodynamic efficiency. This material is based upon work supported by the Department of Energy National Nuclear Security Administration under Award Number DE-NA0001944.

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Authors

  • D.T. Michel

    • Laboratory for Laser Energetics, U. of Rochester

  • A.K. Davis

    • Laboratory for Laser Energetics, U. of Rochester

  • V.N. Goncharov

    • Laboratory for Laser Energetics, U. of Rochester

  • S.P. Regan

    • Laboratory for Laser Energetics, U. of Rochester

  • T.C. Sangster

    • Laboratory for Laser Energetics, U. of Rochester

  • R. Epstein

    • Laboratory for Laser Energetics, U. of Rochester

  • S.X. Hu

    • Laboratory for Laser Energetics, U. of Rochester

  • I.V. Igumenshchev

    • Laboratory for Laser Energetics, U. of Rochester

  • D.D. Meyerhofer

    • Laboratory for Laser Energetics, U. of Rochester

  • W. Seka

    • Laboratory for Laser Energetics, U. of Rochester

  • D.H. Froula

    • Laboratory for Laser Energetics, U. of Rochester