Broadband Optical Reflectance Measurements of Shock-Compressed Si and Ti

ORAL

Abstract

Optical reflectance spectra of shocked material states have historically been difficult to

obtain due to the mm spatial scales and ns timescales of shock-compression

experiments. Nonetheless, such spectra are useful for identifying phase transitions and

understanding electrical conductivity of materials. A new diagnostic and experimental

platform for the OMEGA EP laser facility enables optical reflectance spectrum of shocked

materials to be collected in the waveband 450-750 nm. This talk will present recent results

using this platform for shocked silicon and titanium. The silicon reflectance spectrum is

found to change shape on shocking, indicating a possible change in electronic structure.

The Ti reflectance spectrum is found to stay relatively constant as a function of pressure,

supporting its use as a reflection standard in many previous dynamic compression

experiments.

*This material is based upon work supported by the Department of Energy [National NuclearSecurity Administration] University of Rochester “National Inertial Confinement FusionProgram” under Award Number(s) DE-NA0004144.

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Publication: Planned RSI paper about the reflectance platform for EP and the initial experiments

Presenters

  • Robert Nowak

    • Laboratory for Laser Energetics, University of Rochester

Authors

  • Robert Nowak

    • Laboratory for Laser Energetics, University of Rochester

  • Neel V Kabadi

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

  • 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

  • J. Ryan Rygg

    • Laboratory for Laser Energetics, University of Rochester