An Optimization Method for Matched Abundance-Ratio Cascades by Varying the Key Weight

The theory of multicomponent isotope separation in matched abundance-ratio cascades (MARC) has been well established by Cohen, de la Garza, von Halle, and others. Because separation factors of different isotopes vary in the same separator, isotopic weight fractions cannot be matched in the same sense as in a two-component ideal system. Therefore, the abundance ratios of the desired isotope and a selected key isotope are matched, hence the name. These ratios are matched by choosing a key weight between the two selected components of separation.

Desirable stable isotopes for separation can exist as minor components of a natural, multicomponent isotope system. Behaviors of these isotopes vary within the cascade depending on the relative weight, relative fractions, and relative location in the sequence of isotopes. Various theoretical methods have been developed to simplify analysis and to optimize isotopic separation within a cascade. The possibility of varying key weights within a cascade for optimization was first proposed as future work by de la Garza in 1963, but only a few results have been published showing that varying the key weights can improve efficiency in a theoretical cascade.

This dissertation will review the theory of matched abundance-ratio cascades; examine the behavior of individual isotopes within the cascade; and propose concepts and a methodology for optimizing a cascade by varying the key weight within the cascade.