The KLL Auger spectrum of 65Cu measured from the EC decay of 65Zn

The KLL Auger electron spectrum of 65Cu following the EC decay of 65Zn has been analyzed at the instrumental resolution of 4.5 and 7 eV using a combined electrostatic spectrometer. Energies and relative intensities of the all nine spectrum components were determined and compared with data obtained from X-ray induced spectra for metallic copper and with results of theories as well. Our value of 7041.8(1.3) eV measured for the absolute energy of the dominant KL2L3(1D2) spectrum line was found to be higher by 4 eV than those ones obtained in experiments with the use of X-ray photon excitation and by 11 eV (8σ) than a prediction of the semi-empirical calculations by Larkins. This discrepancy indicates an influence of the “atomic structure effect” on absolute energies of the KLL Auger transitions in 65Cu. Its value was estimated to be from 8 to 15 eV. Good agreement of the measured value of 0.08(2) and that one of 0.066 predicted by relativistic calculation for the KL1L2(3P0/1P1) transition intensity ratio indicates appreciable influence of the relativistic effects on the KLL Auger spectrum even for copper (Z = 29).