Characterisation of a 1[formula omitted] LaBr2.85Cl0.15:Ce crystal for [formula omitted]-rays up to 4.4 MeV

Abstract

This communication reports about complete characterisation of a small volume 1′′×1′′ cylindrical LaBr2.85 Cl0.15:Ce crystal supplied by Scionix Inc. for γ-rays up to 4.4 MeV. The various properties of the crystal studied, are, linearity of response for γ-rays, energy resolution up to 4.4 MeV, timing resolutions, quantification of internal activity, and full energy detection efficiencies for γ-rays from 276 to 4439 keV. Monte Carlo simulation toolkit GEANT4 was used to carry out realistic simulations of the detector’s response for γ-rays. Experimental γ-ray energy spectrum was reproduced in the simulations to estimate the full energy detection efficiency for γ-rays and compared with the measured value. We have obtained energy resolution of ∼3.8% at 662 keV using 2′′ ET-9266B PMT biased at −800 V with the energy signal drawn from the 8th dynode. Timing resolutions of 422 and 364 ps were obtained using 2′′ ET-9807B PMT for 22Na and 60Co, respectively. To the best of our knowledge, this is the first report on the performance of the newly manufactured and marketed LBC crystal. We do not find any significant difference in the performance of LBC from that of a standard Lanthanum Bromide (Ce activated) crystal of similar volume.