Experimental determination of the gadolinium L subshells fluorescence yields and Coster-Kronig transition probabilities

The L subshell Coster-Kronig (CK) transition factors of Gd have been experimentally determined by means of two different experimental approaches and compared to available literature data. On the one hand, reference-free X-ray fluorescence (XRF) analysis using an energy-dispersive detector was applied. This method permitted in addition to determine the L subshell fluorescence yields since the absolute incident and emitted X-ray photon flux can be determined. On the other hand, a wavelength-dispersive spectrometer based on a modified von Hamos geometry using a full cylinder highly annealed pyrolithic graphite crystal was used for an experimental validation of the CK transition factors in an independent experiment. The use of this high energy resolution spectrometer allowed thanks to the capability to better discriminate the different X-ray emission lines to validate the reference-free XRF results. For both experiments, the use of calibrated instrumentation enabled the provision of a reliable uncertainty budget on the results obtained.