High resolution / high sensitivity absorption spectroscopy
BM16 beamline (see the website)
FAME-UHD is dedicated to x-ray absorption spectroscopy in ultra-diluted conditions, for the study of trace elements in samples with environmental, chemical or biological interest. EXAFS analyses can be carried out at concentrations as low as 10ppm and XANES analyses down to less than 1ppm. To do so, a spectrometer constituted of 14 bent crystal analyzers has been built. This type of high resolution detector brings improvements and progresses to the research carried out on the installation through two directions : i) study more and more complex samples and ii) improve and enrich the information obtained about the electronic structure of the probed elements.
Thus, several new scientific opportunities are offered to the user:
> it becomes possible to carry out EXAFS fluorescence measurements on diluted elements in matrices with main constituants which are excited by the incident beam, with a lowered detection limit,
> the resolution of the absorption edge becomes much more precise (high resolution XANES),
> the fine study of the x-ray emission spectrum of the element of interest as a fonction of the energy of the incident photons becomes possible as well (RIXS measurements, Resonnant Inelastic X-ray Scattering).
> XAS, EXAFS, XANES, XES, HERFD-XAS
> In Situ Site-Selective K-edge XAS: A Powerful Probe of the Transformation of Mixed-Valence Compounds, Bordage A., Trannoy V., Proux O., Vitoux H., et al., Physical Chemistry Chemical Physics 17, 17260-17265, (2015).
> Monitoring morphology and hydrogen coverage of subnanometric Pt/y-Al2O3 particles by in situ HERFD-XANES and quantum simulations, Gorczyca A., Moizan V., Chizallet C., Proux O., et al., Angewandte Chemie 53, 12426 –12429, (2014).