Nuisance alarm reduction using PVT: Land and maritime border security

In order to address the challenge of reliably differentiating between Naturally Occurring Radioactive Materials (NORM) and threat sources using low-cost detector materials, Symetrica has applied de-convolution based spectrum-processing techniques to data generated by enhanced PVT detectors. This paper presents data and performance analysis of a range of large-volume PVT detectors (6, 20 and 27 liters) acquired independently and by Symetrica at a range of test facilities. This data will include; results recorded on the Symetrica Radiation Portal Monitor (RPM) test track, at the JRC premises (Ispra) during the ITRAP+10 and the first benchmarking exercise of the SCINTILLA* program. These results demonstrate the power of this new technique. In particular: the ability of portal-scale detectors to resolve the doublet in an HEU source, identify many bare radio-isotopes, to reliably classify containerized NORM and to detect the presence of threat sources both in isolation and in the presence of a containerized NORM.