Radiative lifetimes, branching fractions and oscillator strengths in Pd i and the solar palladium abundance

Abstract

Transition probabilities have been derived for 20 5s-5p transitions of Pd I from a combination of radiative lifetime measurements for 6 odd-parity levels with time-resolved laser-induced fluorescence spectroscopy and of branching fraction determination using a hollow cathode discharge lamp. Additional oscillator strengths for 18 transitions have been determined from measured lifetimes and theoretical branching fractions obtained from configuration interaction calculations with core-polarization effects included. These new results have allowed us to refine the palladium abundance in the solar photosphere: APd = 1.66±0.04, in the usual logarithmic scale, a result in close agreement with the meteoritic value. © ESO 2006.