A coincidence signature library for multicoincidence radionuclide analysis systems

Pacific Northwest National Laboratory (PNNL), Richland, WA, is currently developing multicoincidence systems to perform trace radionuclide analysis at or near the sample collection point for applications that include emergency response, nuclear forensics, and environmental monitoring. Quantifying radionuclide concentrations with these systems requires a library of accurate emission intensities for each detected signature, for all candidate radionuclides. While such data are readily available for single gamma-ray emissions, no signature library has been found for coincident emissions such as β-γ, γ-γ, or β-γ-γ. To meet this need, a Coincidence Lookup Library (CLL) is being developed to calculate the emission intensities of coincident signatures from a user-specified radionuclide, or conversely, to determine the radionuclides that may be responsible for a specific detected coincident signature. The algorithms used to generate absolute emission intensities and various user interfaces for the developmental CLL are described.