MODELING OF MULTISTAGE SELECTIVE PHOTOIONIZATION IN A 3-DIMENSIONAL CAVITY

An analysis is made of physical models of selective three-stage photoi onisation of a vapour in a three-dimensional cavity, These models have been used in theoretical analyses of preparation of significant amoun ts of highly enriched Yb-168 by the AVLIS (atomic-vapour laser isotope separation) method. A comparison of the model predictions with experi ments shows that a three-dimensional model ignoring the absorption of laser radiation in a medium describes well the experimental results ob tained for the second and third ionisation stages. The first excitatio n stage is described satisfactorily by a model in which absorption is included. A comparison of the calculated and experimental results is u sed to find the coefficient (65%) representing ion extraction from a l aser plasma.