Symetrica’s approach to improving the performance of PVT-based portal systems combines an optimised detector design with advanced spectroscopic analysis algorithms. By allowing portal-scale detectors to reliably classify containerised NORM and better detect the presence of threat sources – both in isolation and in the presence of NORM – the solution can reduce the number of nuisance alarms and subsequent referrals to secondary screening facilities.

To enhance the PVT detection technology Symetrica has developed a unique spectroscopic-PVT detector with a continuously operational proprietary stabilisation and health monitoring system that is unaffected by rapid background changes or sources transiting the portal.

Advanced spectroscopic analysis comprises de-convolution-based spectrum processing techniques that enhance effective resolution by reconstructing the most likely incident spectrum and isotope identification algorithms tuned to use these ‘enhanced’ spectra. While similar techniques have been successfully used by Symetrica in Homeland Security applications with crystal scintillators they have never before been applied to large-volume PVT detectors for RPMs.

Effectiveness of the Symetrica solution has been demonstrated in a number of field tests, including an installation at the Port of Antwerp where deployment of a primary screening PVT RPM reduced nuisance alarms by 84%.

Commenting on the announcement, Dr.Geraint Dermody, Symetrica’s Director of Business Development, states: “Our new technology addresses the challenge of reliably differentiating between NORM and threat sources using low-cost detector materials. As a result it is now possible to construct portal-scale detectors that can resolve lines in an HEU source, identify many bare radio isotopes, reliably classify containerised NORM and differentiate between these and threat materials. And as the field tests at Antwerp demonstrate, this means large-volume PVT RPMs that significantly decrease the number of nuisance alarms and, therefore, reduce disruption to the flow of commerce at ports of entry.”