Diamond Light Source
Beamline I20-Scanning - X-ray Spectroscopy (XAS/XES)


The high flux and high spectral purity are the key design parameters of this beamline. The beamline is equipped with an in-house designed four-bounce monochromator which consists of two pairs of counter-rotating crystals. The advantages are: a) high stability and reproducibility, b) fixed exit by geometry, c) energy resolution of transmitted photons not determined by the incident beam divergence and, d) reduction of the tails in the reflectivity curves.

The determination of the local structure around a photoabsorbing atomic site present at low concentration (about 1.0 mM) and/or in X-ray unfavourable heavy matrix is one of the particular strengths of I20-scanning when operating in the conventional scanning XAS mode.

X-ray emission spectroscopy (XES) provides sensitivity to the valence state and the nature of the bound ligands.




Beamline Energy Range
4 - 34 [eV]
Max Flux On Sample
1 * 1012 [ph/s] @ 10 [eV]
Fred Mosselmans
  • Time-resolved studies
Emission or Reflection
  • X-ray fluorescence (XRF)
control/Data analysis
Control Software Type
  • GDA
Data Output Type
  • Spectra
Data Output Format
  • dat/nxs