Searching for the intermediate coupling and correlation effects of the L3- MM Auger spectrum of 169Tm

Abstract

The L 3- MM Auger spectrum of 169Tm from the electron capture decay of 169Yb was analysed at an instrumental resolution of 6.5 eV using an electrostatic spectrometer. Energies and relative intensities of the individual Auger lines and their intermediate coupling components were determined. The absolute energy of the most prominent L 3 M 4 M 5( 1G 4) transition was measured to be 5621.6(1.3) eV i.e. higher by 23 eV than that expected from the semi-empirical calculations by Larkins. The L 3 M 3 M 3 and L 3 M 3 M 4.5 lines were observed to be disposed closer by several eV to the L 3 M 4 M 5( 1G 4) line in the measured spectrum than in the semi-empirical one, which is probably due to the correlation effects. An agreement within 3% was found between the measured relative intensities and those obtained from the intermediate coupling calculations with configuration interaction by Chen for the intense Auger lines, with the exception of the L 3 M 2 M 4,5 line. Predicted (by the intermediate coupling calculations) intensity distributions among the intermediate coupling components of the individual Auger lines were found to agree within two standard deviation limits with the experimental results, with the exception of the L 3 M 3 M 3 and L 3 M 2 M 5 lines.