On the value function for multi-isotope mixtures separation

One of the possible approaches to the introduction of the value function in the case of multi-isotope mixtures is presented. It is based on a simplified model of separation processes in cascades and elements with multiplication of elementary effects of separation. A differential equation, being a necessary condition of the determination of the value function, is derived from the analysis of this model. Its general solution contains arbitrary constants which should be obtained considering boundary conditions and specific features of the separation process. Additional conditions concerning use of the found solutions in cascade criteria of an estimation of separation efficiency are stipulated. The applicability of various kinds of the value function forming at different conditions is analyzed. The forms of the value function which reflect best the optimal cascade with assigned external concentrations of the desired isotope and the matched abundance ratio cascade (MARC) are established.