Radiative lifetimes in Nd II and the solar neodymium abundance

Radiative lifetimes of the eight levels 4f4(5I)6p 6K9/2,11/2,13/2,15/2,17/2,19/20, 4f4(5I)6p (27 448)13/20 and 4f4(5I)6p (29 027)17/20 in Nd II were measured with a laser-ion beam technique using intracavity excitation. The lifetimes of three of the levels have not been measured previously. Four lifetimes were found to be significantly shorter than earlier reported. The measured lifetimes were used to correct old gf-values deduced from arc spectra. The improved gf-values were subsequently used in a solar photosphere abundance analysis based on modern solar models and high resolution solar spectra. The Nd abundance was found to be almost twice as large as that previously reported from photosphere analysis and in very good agreement with meteoritic data. The abundance is ANd = 1.47 ± 0.07 on the scale where ANd = log (NNd/NH) + 12.