Experimental radiative lifetimes, branching fractions, and oscillator strengths of some levels in Y I

We measure the radiative lifetimes of 17 levels in Y I with a time-resolved laser-induced fluorescence technique. Of these 17 levels, 13 are reported on for the first time to the best of our knowledge. Branching fractions for 72 lines related to these Y I levels are determined based on the spectra by the Fourier transform spectrometer at the National Solar Observatory (NSO) on Kitt Peak, USA (http://diglib.nso.edu/ftp.html). By combining the results of lifetimes and branching ratios, the transition probabilities (gA) and oscillator strengths (log(gf)) of these lines are determined. The radiative parameter results obtained in the present work well enrich the atomic database of neutral yttrium, including the experimental values of 62 lifetimes and the gA and log(gf)) of 438 transitions. (c) 2018 Optical Society of America