An emergency response intercomparison exercise using a synthetically generated gamma-ray spectrum

Fast and accurate approach to gamma-spectrum modelling: a validation study with a shielded/unshielded voluminous uranium sample

gamma-Spectrometry is a basic and widely applied method in nuclear security and nuclear safeguards areas. For addressing the growing needs in education and training, in research and development as well as in practical gamma-spectrometry in these areas, Monte Carlo based web-accessible gamma-spectrum modelling tools have been developed for the European Commission's Nucleonica portal at www.nucleonica.net. A recent validation study has demonstrated a good performance of the implemented simulation approach for modelling realistic gamma-spectra from shielded and unshielded point-like sources. In the present work this approach has been further tested with the use of a 0.2kg voluminous 4.46wt% enriched uranium reference material and a portable 10% HPGe detector. The simulations for shielded and unshielded measurement conditions revealed a good agreement with the experimentally acquired gamma-spectra, both for the detection efficiency values and for the overall spectrum shape and intensity in the energy range up to 2.6MeV.