Performance comparison of four compact room-temperature detectors-two cadmium zinc telluride (CZT) semiconductor detectors, a LaCl3(Ce) scintillator, and an NaI(Tl) scintillator

The performance characteristics of four compact, room-temperature detectors-two scintillators and two semiconductor detectors-were studied. All are commercially available detectors. The two scintillators were a o13 mm×13 mm lanthanum chloride [LaCl₃(Ce)] detector and a o25 mm×25 mm sodium iodide [NaI(Tl)] detector. The two semiconductor detectors were a 10×10×3 mm³ cadmium zinc telluride (CZT) detector with a coplanar gridded anode and a 5×5×5 mm³ CZT detector with an extended cathode. The efficiency, resolution, and peak shape of these devices are compared. Since LaCl₃(Ce) is a relatively new commercial scintillator material, additional information on the performance of this detector is presented. Specifically, the impact of naturally occurring radioactive ¹³⁸La and additional contamination from alpha-emitting radionuclides on the background measured with this detector are discussed.