channel time time NO on off Accurate Experimental Lifetimes of Excited Levels in Nd II counts counts counts Counts Ion on off on o f f current

Radiative lifetimes of the six levels 6p3/z(7/2,3/2)2,3,4,5 and 6pl/2(7/2 , 1/2)3,4 in Eu iiare measured with a laser-ion beam technique using intracavity excitation and tandem pumping.

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.

Hyperfine structure measurements of the 4f7(8S:,2)6p y2, (7/2,3/2), ,4 and 4f7(8S0)5d9D:,3,4,5 levels in ls'Eu I1 and Is3Eu I1 have been performed with collinear laser-ion beam technique. The hyperfine structure constants A and B as well as the nuclear electric quadrupole moments Q have been evaluated.

Radiative lifetimes of the eight levels 3d4p ID:, IF:, 'Pi,,,, and 'D:,,,, in Sc I1 have been measured with the beam-laser technique. A comparison with previously reported data shows that lifetime values obtained from beam-foil experiments are about 20% too large and that most of the lifetimes calculated from f-values differ less than 30% from ours.