Abstract:
Nowadays, an increasing number of wavelength-dispersive spectrometers are available at standard X-ray absorption spectroscopy (XAS) beamlines.  Such instruments permit to complement XAS with X-ray emission and resonant inelastic X-ray scattering spectroscopy (XES and RIXS).  Furthermore, XAS is collected with high energy resolution, obtaining a sharpening effect of the spectral features and optimizing the signal-to-background ratio. Both are particularly beneficial in the field of bio-/geo-chemistry, opening the way to the speciation of trace elements in complex matrices and at natural concentrations (below 10 ppm). Three spectrometers recently installed at the European Synchrotron Radiation Facility, and some first results are presented.  The spectrometer of BM16/FAME-UHD with fourteen spherically bent crystal analyzers (SBCAs) of 1 m bending radius has permitted to study selenium speciation at 0.5 ppm. The microprobe station of BM23, coupled with five strip-bent SBCAs of 0.5 m in a compact design, has given insights into how gold incorporates in arsenian pyrites. Finally, the in-vacuum spectrometer of ID26 targets to push these techniques in the tender X-ray energy range.