Theoretical and experimental lifetime and oscillator strength determination in singly ionized neodymium (Nd II)

Abstract

Radiative lifetime measurements were performed with time-resolved laser-induced fluorescence techniques for 24 levels of NdII in the energy range 20 500-32 500 cm-1. For 17 levels, no previous experimental data exist. These results have allowed the testing of new theoretical calculations with the relativistic Hartree-Fock method taking configuration interactions and core-polarization effects into account, and a satisfying agreement has been found for this complex ion. A new set of calculated oscillator strengths, accurate within a few per cent for the strongest transitions, is presented for 107 lines of astrophysical interest appearing in the wavelength range 358.0-1100.0 nm. These results will be useful to evaluate abundance values of neodymium in chemically peculiar stars in relation with cosmochronology.