Radiative lifetimes, branching fractions, transition probabilities and oscillator strengths of some levels for neutral yttrium

The radiative lifetime measurements using the time-resolved laser-induced fluorescence (TR-LIF) technique are reported for 34 levels of Y I between 27 824.50 and 50 254.0 cm−1, among which 27 lifetimes are reported for the first time. The branching fraction (BF) measurements based on the emission spectrum of a hollow cathode lamp (HCL) were performed for 12 of these levels, and the results of 64 lines between 274.250 and 670.063 nm were obtained. By combining them with lifetime values, the transition probabilities and absolute oscillator strengths of these lines were determined. The lifetime and oscillator strength results are in general good agreement with the data by Hannaford et al (Hannaford et al 1982 ApJ 261 736).