A high resolution, 6 channels, silicon drift detector array with integrated JFET's 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 diode (SDD) as a possible detector for X-ray fluorescence excitation spectroscopy. This detector, whose total active area is 21 mm2, combines the advantage of high counting rates with a remarkable energy resolution (ΔE). At room temperature, ΔE at the Mn-Kα line (5.895 keV) is 227 eV FWHM with 0.5 μs Gaussian shaping time constant whereas this value decreases to 139 eV at 150 K with a longer optimum shaping time (5 μs). The resolution at 150 K and 250 ns shaping time is 162 eV allowing high count rate measurements still with a good energy resolution. This paper reproduces the first XAFS spectra recorded in the fluorescence excitation mode with a silicon drift diode. These experiments have been carried out at the ESRF on beamline BL6/ID12A using diluted macrocyclic complexes of cerium (III) as test samples. This choice was motivated by the opportunity to check for the contamination of the LIII-EXAFS oscillations by the LII-edge signatures even though one is able to discriminate in energy between the Lα and Lβ emission lines. (orig.)