Lifetime Measurements in La II with the Beam-Laser Method

Abstract

Cascade-free lifetime measurements of the y 3 F 2 3 4 0 , the z 1 D 2 0 and the z 3 D 1 2 3 0 levels in La II have been made with the beam-laser technique. Our results, together with other recent lifetime measurements in La II, are compared with lifetimes inferred from transition probabilities measured by Corliss and Bozman (CB). An energy-dependent correction factor to the CB lifetimes is found, indicating a misjudgement of the effective temperature in Corliss' and Bozman's arc. A new value of the La solar photosphere abundance based on six transitions in La II, is presented.