Mass Spectrometric Determination of ~(234)U/~(238)U Ratio with Improved Precision

摘要

A new mass spectrometric method is proposed for measurement of ~(234)U/~(238)U ratio with a single Daly electron multiplier detector using the general peak jump method. The method is based on precise measurement of the ~(235)U/~(238)U ratio and ~(234)U/~(235)U ratio, which are used to calculate the ~(234)U/~(238)U ratio using the equation ~(234)U/~(238)U velence ~(235)U/~(238)U X ~(234)U/~(235)U. The results show a significant improvement, i.e., more than 35 times better precision in measuring the ~(234)U/~(238)U ratio with this method (sigma velence 2.9 X 10~(-8)) as compared to direct measurement of ~(234)U/~(238)U (sigma velence 1.1 X 10~(-6)). The method widens the applicability of the single collector system, and it will potentially be helpful to improve the precision in the case of the static multicollector system also.