Abstract

We have developed a multiphoton laser excitation method that allows us to populate selectively msη/ states of barium with I = 0 or 2, m = 7–11, and η = m + 3–20. These atomic states with high core excitations have been called “planetary atoms” because of expected similarities to a classical planetary system.¹ We find that the states occur in two groups: (1) if n ≫ m, the excited core states form well-behaved Rydberg series with constant quantum defects and characteristic lifetimes; (2) if n ≈ m, a dramatic new structure appears. For the first group we have observed sealing laws for quantum defects and autoionization rates which differ significantly from Hartree-Fock calculations. For the second group the new structures appear to be related to anomalously large angular correlations.

© 1985 Optical Society of America