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Extended X-ray Absorption Fine Structure (EXAFS) as a Probe of Temperature and Density in Fe Under Shock-Ramp Compression

ORAL

Abstract

Probing the behavior of iron under the extreme conditions of Earth's core requires innovative experimental techniques. At the Omega EP laser facility, we employed shock-ramp compression to access off-Hugoniot states of Fe at pressures exceeding 400 GPa. Extended X-ray Absorption Fine Structure (EXAFS) spectroscopy was used to extract local atomic structure and temperature information under these conditions. By combining EXAFS data with velocity interferometry (VISAR) measurements, we determined the pressure, density and thermal state of Fe near melting. Our results provide a constraint for the melting line at these extreme conditions. This study demonstrates the effectiveness of EXAFS as a diagnostic tool for investigating temperature under dynamic compression.

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, Lawrence Livermore Natl Lab

  • Andrew Krygier

    Lawrence Livermore National Laboratory

  • Hong Sio

    Lawrence Livermore Natl Lab, Lawrence Livermore National Laboratory

  • Federica Coppari

    Lawrence Livermore National Laboratory

  • David A Chin

    Laboratory for Laser Energetics, University of Rochester

  • Matthew Edward Signor

    University of Rochester

  • J. Ryan R Rygg

    Laboratory for Laser Energetics, University of Rochester

  • Gilbert W Collins

    University of Rochester, Laboratory for Laser Energetics

  • Jon H Eggert

    Lawrence Livermore National Laboratory