The FERRUM project: experimental lifetimes of highly excited Fe II 3d64p levels and transition probabilities

Abstract

We report on measurements of radiative lifetimes in singly ionized iron of six 3d64p levels between 61 512 and 64 041 cm-1, using time-resolved laser-induced fluorescence. Absolute oscillator strengths of 18 Fe II lines in the wavelength range from 2350 to 2800 Å have been obtained by measuring branching fractions for the lines from two Fe II levels with a Fourier-transform spectrometer. The uncertainty in the lifetimes is between 8% and 13%, whereas the uncertainty of the f-values varies between 9% and 19%. A comparison with several previously published values is given.