Room temperature (RT) gamma detectors are simple and easy to use in the verification ofnuclear material. They are normally lighter and smaller than high resolution detectors, whichrequire liquid nitrogen or mechanical cooling. Until recently, routine non-destructive assayverification activities conducted by the IAEA employed two types of RT detectors: sodiumiodide (NaI) and cadmium-zinc-telluride which both have limitations - quite poor resolutionin the first case and low efficiency in the second.The newly-introduced lanthanum bromide (LaBr) detector provides advantages of highdetection efficiency together with higher resolution in comparison with a NaI detector.Additionally, the fast light output provides low dead-time and good performance whenoperating in a high gamma background.This article describes the numerous applications where the IAEA employs the LaBr-basedsystems for safeguards verification purposes, in particular for: fuel rods and fuel pelletsverification; verification of bulk uranium items, including recycled uranium; uranium hold-upmeasurements; and possible applications for plutonium verification.The article also includes a description of the software developed and used for theapplications together with a theoretical study and the numerical modeling carried out for theanalysis of LaBr spectra and interpretation of gamma line intensities into measured materialcharacteristics.
展开▼
