K-shell fluorescence yields and their uncertainties for use in hybrid K-edge densitometry

Hybrid K-edge densitometry (HKED) is a non-destructive analytical assay technique used to provide rapid determination of actinide concentration in tank solutions. Of special interest for HKED is the estimation, along with associated uncertainties, of the ratio of the flouresence yeilds, ω K, of uranium and plutonium. Limited experimental data for ω K(Z) as a function of atomic number, Z, exist and the data are subject to experimental uncertainty. Previous studies have provided values for ω K(Z) with uncertainty estimates but have not included covariance information. We use a phenomenological model with a bootstrapping method to generate the ratio ω K(94)/ω K(92) and associated uncertainty.