Lifetimes of Excited States of Barium and Lanthanum and the Modification of the Hanle Effect by Strong Optical Pumping.

Dieter Zimmermann

L. O. Dickie, F. M. Kelly

The lifetime of the first excited singlet P level of barium, 6s6p1P1, has been determined from the width of the zero field level crossing, i.e. the Hanle effect, of the 6s6p1P1 –6s21S0, 5535 Å resonance line. The resonance radiation was produced in a hollow cathode lamp and the scattering atoms by an atomic beam. After taking account of coherence narrowing, the lifetime is determined to be 8.37 ± 0.14 × 10−9 s, in good agreement with other recent work.

Ludwig L. Shimon, N. M. Érdevdi

D. Aubert, Andr� Baldy, Pierre Baulaigue +1 more

F. M. Kelly, M. S. Mathur

The change in the Hanle effect of the singlet resonance line of neutral barium has been studied over a wide range of density. The low density region has been used to confirm a lifetime of 8.37 ± 0.08 ns for the 6s6p1P1 level. We have determined the cross sections for the relaxation of the multipole moment of order 2 for collisions of the excited level with the ground level and with the metastable 6s5d1D2 level, and comparisons are made with the measured value of [Formula: see text] for the ground level with theoretical predictions.

F. A. Franz