Intraconfiguration Interactions in Barium 6p_1/2nf Autoionizing States

Measurements are reported of the energies and linewidths of the J=2, 3, and 4 components of the 6p _1/2 14f and 6p _1/2 19f states of barium. These states are anomalously broad, having autoionization lifetimes of approximately 1/2 of a classical Rydberg orbit period, and previously measurements have discerned no differences among the various J components. This work shows that the differences can be observed, and are consistent with calculations. The variations between states would be large if the states were LS coupled, but the large 6p ionic fine-structure forces recoupling into jj configurations. The spherical symmetry of the 6p _1/2 ionic state minimizes the differences between J states, but does not eliminate them.