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XUV Femtosecond Absorption Spectroscopy Tabletop (X-FAST) Instrument

The X-FAST instrument is operated for user science by the Wisconsin MRSEC. X-FAST produces femtosecond optical pump pulses and wideband femtosecond extreme ultraviolet (XUV) probe pulses through high-harmonic generation. Transient-absorption spectroscopy in the XUV energy range of 40–120 eV can be performed at X-FAST. This range covers 3d transition metal M edges of other absorption edges of rare earth materials. The transmission measurements focus on thin (20-50 nm) samples including magnetic membranes.

Featuring a gas-cooled sample cell, the X-FAST instrument allows researchers to investigate the dynamics of thermally sensitive thin-film samples without compromising their integrity. X-FAST opens new avenues for studying electronic structure dynamics in materials and molecular systems at the femtosecond timescale with element-specific core-hole sensitivity.

Instrument Parameters

  • XUV Probe:
  • Photon energy:   40 -72 eV/72 - 120 eV (Al filter/Zr Filter)
  • Beam diameter at sample:   ~ 70 μm
  • Pulse length:   ~35 fs
  • Vis/IR Pump:
  • Wavelength:   400-800 nm
  • Beam Dia. at sample:   ~200 μm
  • Pulse length:  ~50 fs
  • Spectrometer Resolution:   < 150 meV

For more information regarding the instrument and sample environment please see the instrumentation paper: https://bergmann.physics.wisc.edu/wp-content/uploads/2024/02/pub229.pdf

Facility Type: 
X-ray Diffraction

Instruments

  1. XUV Femtosecond Absorption Spectroscopy Tabletop (X-FAST) Instrument

    The X-FAST instrument is operated for user science by the Wisconsin MRSEC. X-FAST produces femtosecond optical pump pulses and wideband femtosecond extreme ultraviolet (XUV) probe pulses through high-harmonic generation. Transient-absorption spectroscopy in the XUV energy range of 40–120 eV can be performed at X-FAST. This range covers 3d transition metal M edges of other absorption edges of rare earth materials. The transmission measurements focus on thin (20-50 nm) samples including magnetic membranes.