Interpreting EXAFS Spectra: Toward Ramp-Compression Studies of Iron Oxide

POSTER

Abstract

Extended x-ray absorption fine structure (EXAFS) spectroscopy will be used to characterize iron oxide (FeO) ramp compressed to Mbar pressures. EXAFS spectroscopy provides information about the local structure, density, and temperature in compressed materials. The interpretation of the EXAFS spectral modulations was studied using ambient temperature FeO absorption data obtained with the Advanced Photon Source (APS) synchrotron[1] and theoretical predictions. The FeO data were evaluated by degrading the signal-counting statistics and background levels to understand how future spectrometer development will improve the data obtained in planned experiments at the Omega Laser Facility.[2] This analysis and spectrometer development will be applied to experiments using FeO compressed to conditions analogous to the Earth’s lower mantle and core in order to increase our understanding of the formation and evolution of the Earth and iron-rich exoplanets.

[1] XAFS Spectral Library, Spectrum: FeO data, 13 June 2018, http://cars.uchicago.edu/xaslib/spectrum/611.

[2] T. R. Boehly et al., Opt. Commun. 133, 495 (1997).

Presenters

  • David Alexander Chin

    Univ of Rochester

Authors

  • David Alexander Chin

    Univ of Rochester

  • Philip M. Nilson

    Laboratory for Laser Energetics

  • James Ryan Rygg

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

  • Thomas Boehly

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

  • Gilbert W Collins

    University of Rochester, Departments of Mechanical Engineering, Physics and Astronomy, and Laboratory for Laser Energetics, Laboratory for Laser Energetics, Univ of Rochester, Laboratory for Laser Energetics, U. of Rochester, Univ of Rochester, Laboratory for Laser Energetics, University of Rochester, University of Rochester, Laboratory for Laser Energetics

  • Federica Coppari

    Lawrence Livermore Natl Lab

  • Yuan Ping

    LLNL, Lawrence Livermore National Laborator, Lawrence Livermore Natl Lab, Lawrence Livermore National Laboratory, Lawrence Livermore National Lab