The experimental investigation of weak effects in the KLL Auger electron spectrum of Zr and Nb generated in radioactive decay

• Published in: Journal of electron spectroscopy and related phenomena 2018-12, Vol.229, p.61-67
• Main Authors: Inoyatov, А.Kh, Kovalík, A., Perevoshchikov, L.L., Filosofov, D.V., Ekman, J., Vénos, D., Muminov, T.M., Radchenko, V., Zhdanov, V.S
• Format: Article
• Language: English
• Subjects: 90Nb; 90Zr; 91mNb; Atomic structure effect; calculations; KLL Auger transitions; Multiconfiguration Dirac-Hartree-Fock; Multiconfiguration Dirac-Hartree-Fock calculations; Nb-90; Nb-91m; Zr-90
• ISSN: 0368-2048; 1873-2526; 1873-2526
• DOI: 10.1016/j.elspec.2018.08.004

•The KLL Auger electron spectra of Zr and Nb investigated in detail.•Energies, relative intensities, and natural widths of spectrum components determined.•Results of our ab initio multiconfiguration Dirac-Hartree-Fock calculations discussed.•An influence of the atomic structure effect on the Zr absolute energies found.•An impact of the relativistic effects on the KL1L2(3P0) transition intensity observed. The KLL Auger electron spectra of Zr (Z = 40) and Nb (Z = 41) following respectively the electron capture (EC) decay of 90Nb and the de-excitation of the isomeric state of 91mNb were investigated in detail using a combined electrostatic electron spectrometer and radioactive sources prepared by surface sorption on a polycrystalline carbon substrate. For both elements, energies, relative intensities, and natural widths of all the nine well-resolved basic spectrum components were determined and compared with theoretical predictions and with results of previous measurement as well. Results of our ab initio multiconfiguration Dirac-Hartree-Fock calculations are discussed also in relation to the solid-state effect. Indications of an influence of the EC decay on the absolute energy of the KL2L3(1D2) transition (so-called atomic structure effect) in Zr were found. The effect of the retarded current-current interaction on the KL1L2(3P0) transition intensity was observed to be appreciable for the investigated elements in accordance with the prediction.