Resonant three-Photon Ionization Spectroscopy of Atomic Fe...

Laser spectroscopic investigations on high-lying states around the ionization potential in the atomic spectrum of Fe have been carried out for development of a practical three-step resonance ionization scheme accessible by Ti:Sapphire lasers. A hot cavity laser ion source typically used at on-line radioactive ion beam production facilities was employed in this work. Ionization schemes employing high-lying Rydberg and autoionizing states populated by three-photon excitations were established. Five new Rydberg and autoionizing Rydberg series converging to the ground and to the first four excited states of Fe II are reported. Analyses of the Rydberg series yield the value 63737.686 ± 0.068 cm-1 for the ionization potential of iron.