CZT/NaI hybrid hand-held performance evaluation

Abstract

New hybrid spectroscopic systems directly combine spectra from detectors with very different energy resolutions, accommodating standard analyses of the output hybrid spectrum. Hand-held hybrid systems consisting of a 0.5 cm3 cadmium zinc telluride detector combined with either a 1 cm3 NaI(Tl) scintillator mounted on a photomultiplier tube or a 1 cm3 CsI(Tl) mounted on a silicon photomultiplier were evaluated for performance by source measurements for a variety of acquisition times. Repeated 300 second background measurements were analyzed and found a small increase in false alarm rate for the hybrid combinations compared to the individual component detectors. Repeated measurements with a 100 μR/h 137Cs source and acquisition times of 5, 10, 30, 100, and 300 seconds were analyzed, with the results showing that hybridization significantly enhances peak detectability relative to the individual constituent detectors, especially at shorter times. At 5 and 10 seconds, the probability of detection was more than twice that of the individual components. The hybrid approach enables the consideration of a greater variety of measurement system solutions in terms of cost and performance.