Studying the properties and response of a large volume (946 cm3) LaBr3:Ce detector with γ-rays up to 22.5 MeV

This paper presents the results of our measurements and detailed simulations using GEANT4 to investigate the performance of a large volume (946 cm3) cylindrical (3.5in.diameter×6in.length) LaBr3:Ce detector. The properties of the detector have been studied using γ-rays from radioactive sources and in-beam reaction, from few hundred keV to 22.5 MeV. The salient features, which have been studied in-depth, are the uniformity and internal activity of the crystal, the energy and timing resolutions, linearity of the response up to 22.5 MeV, and efficiencies. A highly linear response has been observed by extracting the energy signal from a lower dynode and operating the PMT at a low voltage. The detector is to be primarily used for measuring high energy γ-rays spectra from Giant Dipole Resonance (GDR) decay studies.