EXAFS and X-ray diffraction measurements for Iron near the melting line

ORAL

Abstract

Complex laser pulse shaping capabilities have enabled access to previously unexplored regions of pressure-temperature space by facilitating dynamic compression paths that traverse the region between the shock Hugoniot and ramp quasi-isentrope. Utilizing the state-of-the-art pulse shaping capabilities of the Omega EP laser at the Laboratory for Laser Energetics, we performed a series of shock-ramp compression experiments to probe the structure and thermal state of the hcp phase of Fe near melting at pressures exceeding 400 GPa. Extended X-ray Absorption Fine Structure (EXAFS), x-ray diffraction, and velocity interferometry (VISAR) diagnostics have been used to determine the pressure, density, and temperature of Fe. Our data show no evidence for the emergence of a high-temperature body-centered cubic (bcc) phase under our experimental conditions and provide a constraint for the melting line up to 600GPa.

*This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

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Presenters

  • Yuan Ping

    • Lawrence Livermore National Laboratory

Authors

  • Yuan Ping

    • Lawrence Livermore National Laboratory

  • Amy L Coleman

    • Lawrence Livermore National Laboratory

  • Stanimir A Bonev

    • Lawrence Livermore National Laboratory

  • T. E. Lockard

    • Lawrence Livermore National Lab

  • Andrew Krygier

    • Lawrence Livermore National Laboratory

  • Hong Sio

    • Lawrence Livermore National Laboratory

  • Raymond F Smith

    • Lawrence Livermore National Laboratory

  • Christine J Wu

    • Lawrence Livermore National Laboratory

  • Jon Henry Eggert

    • Lawrence Livermore National Laboratory

  • Robert E Rudd

    • Lawrence Livermore National Laboratory

  • James M McNaney

    • Lawrence Livermore National Laboratory

  • David Alexander Chin

    • University of Rochester
    • Laboratory for Laser Energetics
    • Laboratory for Laser Energetics, University of Rochester, Rochester, NY, United States

  • Matthew Edward Signor

    • University of Rochester
    • Department of Physics and Astronomy, University of Rochester, Rochester, NY, United States

  • J. Ryan Rygg

    • Laboratory for Laser Energetics, University of Rochester

  • Gilbert W Collins

    • University of Rochester
    • Laboratory for Laser Energetics, University of Rochester
    • Department of Physics and Astronomy, University of Rochester, Rochester, NY, United States