Calibration and experimental comparison of the active well coincidence counter and PHONID-II

A team from EURATOM-Luxembourg, JRC-Ispra, Los Alamos, and International Atomic Energy Agency (IAEA) has performed measurements to directly compare the Active Well Coincidence Counter (AWCC) with the PHONID-II for the assay of highly enriched uranium (HEU). The comparison included an evaluation of counting rates, sensitivity, accuracy, linearity, stability, and matrix effects. Samples used in the evaluation included highly enriched uranium metal, U3O8 U-Al alloy plates, UF4, and (uranium/thorium) coated particles covering the mass range from a few grams up to about 5 kg of 235U. These materials are typical of the HEU samples under inspector verification. This report gives the results of the intercomparison as well as calibration information for the above material categories