Laser resonant photoionization spectroscopy of highly excited and autoionization states of terbium atoms

The energies of unknown highly excited states of terbium atom have been measured by multistep laser excitation followed by photoionization: 19 odd and 25 even states in the 32300-35400 cm -1 energy region with an accuracy of +or-0.3 cm -1 and 135 odd and 85 even autoionization states in the 47800-52700 cm -1 energy region with an accuracy of 3 cm -1 were investigated. The optimal three-step schemes of Tb atom photoionization through autoionization states in the yellow-green region of the spectrum have been defined.