Intrinsic radiation background of LaBr3(Ce) detector via coincidence measurements and simulations
Abstract
The LaBr3(Ce) detector has attracted much attention in recent years for its superior characteristics to other scintillating materials in terms of resolution and efficiency. However, it has relatively high intrinsic radiation background due to the naturally occurring radioisotope in lanthanum, actinium and their daughter nuclei. This limits its applications in low counting rate experiments. In this paper, we identified the radioactive isotopes in the φ3''× 3'' Saint-Gobain B380 detector by a coincidence measurement using a Clover detector in a low-background shielding system. Moreover, we carried out a Geant4 simulation to the experimental spectra to evaluate the activities of the main internal radiation components. % by means of the α, γ and β decays from the 138La and 227Ac. The activity of radiation background of B380 is determined to be 1.480 (69) Bq/cm3, the main sources of which include 138La of 1.425 (59) Bq/cm3, 211Bi of 0.0136 (15) Bq/cm3, 219Rn of 0.0125 (17) Bq/cm3, 223Ra of 0.0127 (14) Bq/cm3, and 227Th of 0.0158 (22) Bq/cm3.