Characterization of LaCl3:Ce detectors for gamma spectroscopy

Abstract

Cerium (Ce) doped LaCl3 and LaBr3 have been invented by Delft and Bern Universities and some other groups. Their commercial availability has been made by Saint-Gobain. This project aims to characterize LaCl3:Ce scintillator detector for the gamma ray spectrometry. The study includes determination of detection efficiency, energy resolution, time resolution and photo-fraction. LaCl3:Ce detector of the size 25.4 mm × 25.4 mm doped with 0.9% of Ce has good linear response and good energy resolution for gamma rays at room temperature. Timing resolution is also obtained with two LaCl3 detectors operating in coincidence using Na-22 sources that emits 511 keV gammas. The photo-peak efficiency and photo-fraction of 662keV and 1120keV gamma-rays are measured. The absolute photo-peak efficiency and absolute total detection efficiency are measured with Co-60 and corrected for coincidence summing. Also, the measured results are reproduced by GEANT4 simulations assuming detector in a realistic geometry.