HIGH-RESOLUTION, 6 CHANNELS, SILICON DRIFT DETECTOR ARRAY WITH INTEGRATED JFET DESIGNED FOR XAFS SPECTROSCOPY - FIRST X-RAY-FLUORESCENCE EXCITATION-SPECTRA RECORDED AT THE ESRF

We have investigated the performances of a 6 channel silicon drift dio de (SDD) as a possible detector for X-ray fluorescence excitation spec troscopy. This detector, whose total active area is 21 mm(2), combines the advantage of high counting rates with a remarkable energy resolut ion (Delta E). At room temperature, Delta E at the Mn-K-alpha line (5. 895 keV) is 227 eV FWHM with 0.5 mu s Gaussian shaping time constant w hereas this value decreases to 139 eV at 150 K with a longer optimum s haping time (5 mu s). The resolution at 150 K and 250 ns shaping time is 162 eV allowing high count rate measurements still with a good ener gy resolution. This paper reproduces the first XAFS spectra recorded i n the fluorescence excitation mode with a silicon drift diode. These e xperiments have been carried out at the ESRF on beamline BL6/ID12A usi ng diluted macrocyclic complexes of cerium (III) as test samples. This choice was motivated by the opportunity to check for the contaminatio n of the L(III)-EXAFS oscillations by the L(II)-edge signatures even t hough one is able to discriminate in energy between the L(alpha) and L (beta) emission lines.