Experimental Branching Fractions, Transition Probabilities, and Oscillator Strengths of La <scp>ii</scp>

Abstract Branching fractions of 86 La ii lines in the spectral range of 243.340–626.229 nm have been measured using a grating spectrometer based on the emission spectra of a lanthanum hollow cathode lamp. Combining these branching fractions with previously measured radiative lifetimes using the time-resolved laser-induced fluorescence technique, transition probabilities and oscillator strengths were determined for 86 lines belonging to transitions 5 d 2 –4 f 5 d , 5 d 6 s –4 f 5 d , 4 f 6 s –5 d 7s, 4 f 5 d –5 d 7s, 5 d 6 p –5 d 7s, 4 f 6 s –5 d 6 d , 4 f 5 d –5 d 6 d , 5 d 6 p –5 d 6 d , 6 s 6 p –5 d 6 d , 4 f 5 d –4 f 2 , and 5 d 6 p –4 f 2 . These fundamental atomic parameters are important for deriving chemical abundances from astronomical spectra by the method of equivalent widths or synthetic spectra.