Full-field XANES imaging

Professor L. Vincze (Ghent University, Belgium) and his colleagues have reported on the latest fluorescence mode XANES imaging using the SLcam, which is an energy dispersive pnCCD detector. At BM26A, ESRF, the measurements were done for iron foil with some oxides and geological standard samples. The typical detection limit and measuring time were 0.5 wt% and 15 h, respectively. Readers might think that energy-resolution can be sacrificed near the absorption edges of interest in order to shorten the measuring time in the same way as ordinary XANES measurement by means of X-ray fluorescence. Although the use of ordinary X-ray CCD in accumulation mode for a very similar experiment was published 10 years ago (for example, M. Mizusawa et al, J. Synchrotron Rad. 11, 209 (2004)), the present system has the advantage of being able to reduce the background from the major light elements contained in the sample. For more information, see the paper, "Full-Field Fluorescence Mode Micro-XANES Imaging Using a Unique Energy Dispersive CCD Detector", P. Tack et al, Anal. Chem., 86, 8791(2014).