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Sensitivity Study of DT Cryogenic Implosions to Laser-Drive Nonuniformities Based on Explosion Phase Measurements on OMEGA

ORAL

Abstract

Low (l ≤ 6) and mid ( 6 < l ≤ 10) mode asymmetries, seeded by laser-drive nonuniformities and amplified by hydrodynamic instabilities, are possible performance degradation mechanisms for laser-direct-drive implosions on OMEGA. The nonuniformity is diagnosed from the x-ray emission limb at the corona–fuel interface during the explosion phase. The perturbations seeded by laser drive nonuniformity are varied by changing the ratio of the initial beam radius (Rb) to the target radius (Rt). This work presents an Rb/Rt scan of DT cryogenic implosions on OMEGA using explosion phase x-ray measurements. The x-ray emission from the implosion is recorded using a filtered, 16-pinhole array imager and an x-ray framing camera. The x-ray images have a spatial resolution of 15 mm and 40 ps temporal integration. A modal analysis is applied to the spatial distribution of the x rays and the rms amplitude for a set of implosions is presented as a function of Rb/Rt along with the evolution of the low and mid modes. Forward modeling of the x-ray framing camera is carried out using a Monte Carlo simulation to optimize the experimental design and to determine the error in the measurements. This material is based upon work supported by the Department of Energy National Nuclear Security Administration under Award Number DE-NA0003856.

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Presenters

  • Joshua Baltazar

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

Authors

  • Joshua Baltazar

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

  • Christian Stoeckl

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

  • 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

  • Varchas Gopalaswamy

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

  • James P Knauer

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

  • Dhrumir P Patel

    University of Rochester

  • Wolfgang R Theobald

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

  • Ka Ming M Woo

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

  • Sean P Regan

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