Selectivity of two-stage photoionization of atoms

A fairly general kinetic scheme is used in an analysis of two-stage pulse laser photoionization of a mixture of two isotopes. Expressions for the total number of selected ions, quantum efficiency, and separation coefficient are derived allowing for the resonant transfer of the excitation, charge exchange, and deterioration of the excitation selectivity due to absorption in the laser line wings. Various schemes for the separation of the required atoms are considered from the point of view of yield and efficiency of the method.