%0 Journal Article
%T Experimental and theoretical lifetimes and transition probabilities for spectral lines in Nb£¿II
%A H. Hartman
%A H. Lundberg
%A H. Nilsson
%A L. Engstr£¿m
%A P. Palmeri
%A P. Quinet
%J -
%D 2019
%R 10.1051/0004-6361/201935614
%X <i>Aims<i/>. We have measured and calculated lifetimes of high lying levels in Nb£¿II, and derived absolute transition probabilities by combining the lifetimes with experimental branching fractions.<i>Methods<i/>. The lifetimes were measured using time-resolved laser-induced fluorescence in a two-photon and two-step excitation scheme. The branching fractions were measured in intensity calibrated spectra from a hollow cathode discharge, recorded with a Fourier transform spectrometer. The calculations were performed with the relativistic Hartree¨CFock method including core polarization.<i>Results<i/>. We report experimental lifetimes of 13 levels in the 4d<sup>3<sup/>(<sup>4<sup/>F)5d and 4d<sup>3<sup/>(<sup>4<sup/>F)6s subconfigurations, at an energy around 70 000 cm<sup>£¿1<sup/>. By combining the lifetimes with experimental branching fractions absolute transition probabilities of 59 lines are derived. The experimental results are compared with calculated values
%U https://www.aanda.org/articles/aa/full_html/2019/07/aa35614-19/aa35614-19.html