Selective Photoionization Scheme for Atomic Gadolinium Laser Isotope Separation

The selective photoionization scheme for separating 157Gd from natural gadolinium and the laser irradiation conditions in order to enrich 157Gd to 60-80% are discussed in the case of twoand three-step photoionization. The dependence of excitation pathways on J-values is also discussed. From the view point of ionization rate it is preferable to select the four-colour threestep photoionization scheme by using both the ground and the lowest metastable levels. Optimum laser irradiation conditions for gadolinium isotope separation are presented.