Two photon resonant excitation of Copper–Rydberg levels (original) (raw)

The 2-photon resonant, 3-photon ionization spectrum of gaseous atomic copper is presented. The 2 D 5/2 3d 10 nd ← 2 S 1/2 3d 10 4s (n = 9-21) Rydberg series is observed in 2-photon excitation. The term energies of this series converge to the lowest ionization threshold with an apparent quantum defect of 0.92. The state which couples the ground 2 S 1/2 3d 10 4s state of copper to the 2 D 5/2 3d 10 nd Rydberg series is a non-stationary state composed primarily of the spin-orbit components of the lowest 2 P o atomic states.