The predicted influence of relativistic effects on the KL1L2(3P0) Auger transition intensity of thulium proved

Abstract

The KLL Auger spectrum of thulium from 169Yb decay has been analysed at an instrumental resolution of 13 eV using a combined electrostatic spectrometer. Energies and relative intensities of the individual KLL transitions have been determined and compared with calculations. A reliable value of 0.67(5) for the KL1L2(3P0)/(1P1) transition intensity ratio obtained from our partly resolved KL1L2 doublet proved, for the first time, a sharp increase of the KL1L2(3P0) intensity in the high Z region due to the relativistic effects predicted by relativistic calculations in intermediate coupling with configuration interaction. For the first time, a broadening of the KLL Auger lines, probably due to the two different excitation ways of the 169Tm atoms in 169Yb decay (K-internal conversion and K-electron capture), has been observed. A value of 19.5(8) eV was obtained for the energy separation of the two thulium KLL Auger spectra shifted to each other, arising from the individual excitation modes, and that of 0.81(9) for their intensity ratio (`K-conversion' to `K-capture'). © 1997 Elsevier Science B.V.