BL4-3

    Overview
    SPEAR3

    20-pole, 2.0-Tesla Wiggler, 0.75 mrad, Side Station

    Beam line 4-3 is a wiggler side-station dedicated for x-ray absorption spectroscopy and EXAFS measurements on biological, environmental, catalysis, and materials systems. This station enables tender x-ray measurement (S K-edge and up, i.e. 2.4-5 keV) in addition to hard x-rays ( up to 11 keV). It is setup with a He flight path from the beam line optics to the sample. The beam is collimated and unfocused to allow for high energy-resolution measurements on homogenous samples. BL4-3 is equipped with a 4-element solid-state silicon drift detector in addition to ionization chambers and PIPS/Lytle detectors. A LHe cryostream allows for low-temperature measurements. A motorized sample holder stage allows sequential measurement on multiple samples. Infrastructure for in-situ catalysis with mass-flow control and reactor cells have recently been added.

    Sample Environment

    Sample Temperature 20-50 K (He cryostream) or Room temperature (no cryostat)
    Sample size 5 X 20 mm
    Catalysis Reactor cells
    Minimum Sample Requirement 2-5 mM, 200 ul or 100 ppm, 2-5 mg at tender energies. 2 mM, 200 μl solutions or 10 ppm, 10 mg solids at higher energies. Automatic scan queueing available for multiple room temperature samples and/or multiple spots on cold samples.
    Other Ambient He atmosphere in gas tight sample box (room temperature) plastic sample compartment (for He cryostream)

    Instrumentation

    Detectors Ionization chambers, PIPS, Lytle, Hitachi HTA 4-element solid-state Si drift detector, electron-yield detector
    Cryostat LHe cryostream
    Other He-purged sample box. He flow meters and oxygen content meter on sample space. Automated shutter to alleviate beam damage. Motorized multiple solid-sample holder. Gas cabinet, mass flow control, reactor cells for in-situ catalysis.

    Technical Specifications

    Energy

    Energy Range Resolution ΔE/E Spot Size Flux
    Unfocused 2400-11000 eV 1 x 10-4 2 x 12mm2 1 x 1012

    Optics

    M0 Monochromator
    Vertically collimating, flat, bent, 1.0 m, bare Si, cutoff ~10.5 keV Liquid N2 cooled, Si(111), ϕ = 0o & 90o, double-crystal, non-fixed exit slit Monochromator Crystal Glitch Library

    Absorption

    127 micron Be

    Publications

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