Radiative lifetimes and gJfactors of low-lying even-parity levels in the Yb I spectrum

Radiative lifetimes and g J factors of lower-lying even-parity levels in the Yb I spectrum have been determined by time-resolved fluorescence spectroscopy. An improved source for metastable atoms, reducing magnetic stray fields, was applied in the measurements of J=3 states. The results are: 6s6d 1 D 2 : tau =35.2(10) ns, g J =1.020(7); 6s6d 3 D 3 : tau =23.4(11) ns, g J =1.354(15); 6s7d 1 D 2 : tau =49.8(20) ns, g J =1.111(12); 6s7d 3 D 3 : tau =43.1(12) ns, g J =1.338(7); 6s7d 3 D 2 : tau =66.5(36) ns, g J =1.079(7); 6s7d 3 D 1 : tau =38.4(17) ns, g J =0.508(5); 6s7s 3 S 1 : tau =15.9(19) ns, g J =2.01(1); 6s8s 2 S 1 : tau =34.3(42) ns, g J =2.01(1); 6s8s 1 S 0 : tau =37.9(42) ns. The lifetime data have been compared with Coulomb approximation calculations and experimental values taken from measurements of transition probabilities.