Even-Parity Rydberg And Autoionizing States Of Lutetium By Laser Resonance-Ionization Spectroscopy

Multistep laser resonance ionization spectroscopy of lutetium (Lu) has been performed at TRIUMF's off-line laser ion source test stand. The even-parity Rydberg series 6s(2)nd D-2(3/2), 6s(2)nd D-2(5/2), and 6s(2)ns S-2(1/2) were observed converging to the 6s(2) ionization potential. The experimental results have been compared to those of previous work. Fifty-one levels of Rydberg series 6s(2)nd D-2(5/2) and 52 levels of Rydberg series 6s(2)ns S-2(1/2) were reported. Additionally, six even-parity autoionization (AI) series converging to Lu ionic states 5d6s D-3(1) and 5d6s D-3(2) were observed. The level energies of these AI states were measured. The configurations of the AI states were assigned by relativistic multichannel theory within the framework of multichannel quantum defect theory.