Figure 2
Uranium LIII-edge XANES data of sediment from Rifle, Colorado, containing primarily monomeric U(IV) species (see Sharp et al., 2011BB13), collected using (a) the X-ray microbeam and (b) the large beam (500 µm × 500 µm). Oxidation of monomeric U(IV) by the microbeam between the first scan (dotted line) and the average of seven subsequent scans (solid line) is shown by the shift in the white line and particularly the flattening in the post-edge region centred around 17.19 keV (a). A uranyl acetate U(VI) standard is included for reference (dashed line). There is little change in spectral shape observed between the first scan (dotted line) and the average of nine subsequent scans (solid line) under the large beam (b).  [article HTML]

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