Plastic scintillation spectrometry

Plastic scintillators provide homeland security organisations with large area, low cost gamma-ray counters at international borders. Currently these detectors cannot distinguish between the sources they detect, leading to high false alarm rates during primary screening. These alarms must be followed up by time consuming secondary screening techniques using spectroscopic detectors. Here we review current PVT scintillators and present a range of techniques that optimise their characteristics. By combining these optimisations with Symetrica's spectral deconvolution and isotope identification software, PVT detectors were given isotope identification ability. Far from being simple gamma-ray counters, these detectors were used to successfully identify a range of complex isotopes, such as Eu-152, Ra-226 and Th-232. The resulting clarity produced by these detectors was impressive, with a measured full width at half maximum of ~5% at 662keV in deconvolved Cs-137 spectrum. Detector designs are also presented here which allow PVT detectors to identify a full range of isotopes during primary screening, potentially eradicating the need for follow up examinations