Radiative lifetime and oscillator strength determinations in Sm III

¹ Astrophysique et Spectroscopie, Université de Mons-Hainaut, 7000 Mons, Belgium
² IPNAS (Bât. B15), Université de Liège, Sart Tilman, 4000 Liège, Belgium
³ Lund Observatory, Box 43, Lund University, 221 00 Lund, Sweden
⁴ Department of Physics, Lund Institute of Technology, PO Box 118, 221 00 Lund, Sweden

Corresponding authors: E. Biémont, E.Biemont@ulg.ac.be or P. Quinet, quinet@umh.ac.be

Received: 25 October 2002
Accepted: 22 November 2002

Abstract

Radiative lifetimes of 6 levels belonging to the 4f⁵(⁶H°, ⁶F°)5d configuration of Sm III have been measured for the first time using a time-resolved laser-induced fluorescence technique. Experimental data have been compared with semi-empirical calculations. The agreement is excellent for 4 levels with ⁶F° as a parent term. Larger discrepancies (53 and 37%) are observed for 2 levels with ⁶H° and ⁶F°, respectively, as a parent term and are explainable by strong mixing and cancellation effects occurring in the line strength calculations which are responsible of “instabilities” occurring in the lifetimes considered as a function of J value within the term. Branching ratios for the lines depopulating the levels of interest have been measured by Fourier transform spectroscopy. A first set of oscillator strengths has been deduced for this ion.