New radiative lifetime measurements using time-resolved laser-induced Ñuorescence are reported for the lowest six even-parity levels of Eu II. Branching fractions, measured from Fourier transform spectra, are combined with these lifetimes to determine atomic transition probabilities for the strongest blueÈUV lines and additional yellowÈred lines of Eu II. These results are compared with published data, and generally good agreement is found. Recommended hyperÐne structure constants and isotopic shifts for these lines are also assembled from the literature and supplemented, as needed, using results from nonlinear least-squares Ðts of line proÐles in Fourier transform spectra. These laboratory data are applied in a new determination of the solar Eu elemental abundance, yielding with^0.04 Slog 10 e(Eu)T \ 0.52^0.01, estimated for each of internal (scatter) and external (systematic) uncertainties. From analysis of the proÐles of three Eu II lines, primarily j4129, isotopic fractions of 151Eu and 153Eu are shown to be consistent with their values in meteoritic material.

We use time-resolved laser-induced fluorescence to measure the lifetime of 186 Fe levels with energies between 25 900 and 60 758 cm . Measured emission branching fractions for these levels yield transition probabilities for 1174 transitions in the range 225-2666 nm. We find another 640 Fe transition probabilities by interpolating level populations in the inductively coupled plasma spectral source. We demonstrate the reliability of the interpolation method by comparing our transition probabilities with absorption oscillator strengths measured by the Oxford group [Blackwell et al., Mon. Not. R. Astron. Soc. 201, 595-602 (1982)]. We derive precise Fe level energies to support the automated method that is used to identify transitions in our spectra.

A B S T R A C TBy a combination of radiative lifetimes measured using the fast-beam-laser method and experimental branching ratios deduced from Fourier transform spectrometer spectra, it has been possible to derive experimental f-values for Lu ii lines observed in the visible and nearultraviolet regions. These data are compared with relativistic Hartree±Fock calculations, taking core polarization effects into account, and a set of additional oscillator strengths of astrophysical interest is presented.

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