New atomic lifetime results for some levels of neutral yttrium

Radiative lifetimes have been determined for the z2D0sub(3/2,5/2), z2F0sub(5/2,7/2), y2D0sub(3/2,5/2), y2P0sub(3/2) and y2F0sub(5/2,7/2) levels of neutral yttrium using technique of laser excited fluorescence from sputtered metal vapours. The results differ significantly from previously reported values obtained by the Hanle and level-crossing techniques and by beam-foil and beam-sputtering techniques, but they are consistent with relative lifetime values derived from the recent hook data of Cardon et al (J. Opt. Soc. Am.; 70:1372 (1980)). The new lifetime results are used to determine a revised normalisation factor for the conversion of Cardon's relative f values into absolute values. (author)