Measurements of oscillator strenghts in Zr II and Cr II

Sammanfattning: Experimental oscillator strenghts (f-values) for lines in Zr II and Cr II have been determined using branching fractions (BFs) and radiative lifetimes. Experimental log gf-values for 263 spectral lines in Zr II have been derived by combining previously measured lifetimes with new BFs measured on the Lund UV Fourier Transform Spectrometer (FTS). The oscillator strengths have been used to determine the solar zirconium abundance, to log eZr=2.58 +-0.03. New radiative lifetimes have been measured for ten energy levels in Cr II using the laser-induced fluorescence (LIF) technique at Lund Laser Centre (LLC). By combining these and other previously measured lifetimes with new experimental BFs measured on the Lund FTS, log gf-values for 119 spectral lines were determined.