Characterization of 2′′×2′′ LaBr3(Ce) scintillators for fast-timing spectroscopy

Abstract

The present study primarily reports on the complete characterization of $2^{\prime \prime }\times 2^{\prime \prime }$ LaBr₃(Ce) scintillators coupled to fast Hamamatsu R2083 photomultiplier tubes (PMTs). The energy characteristics of the detector, such as linearity response, energy resolution, and intrinsic efficiency, are thoroughly investigated using standard radioactive sources (¹³⁷Cs, ⁶⁰Co, and ¹⁵²Eu). The experimentally measured energy spectra and the intrinsic efficiency are compared with the GEANT4 simulations, indicating an overall good agreement between the measured and simulated results. In addition, the timing characteristics of the detectors are studied with a ⁶⁰Co source. The time resolution is optimized by varying the PMT bias voltages and Constant Fraction Discriminator (CFD) delays. The best time resolution for an individual LaBr₃(Ce) scintillator coupled to R2083 PMT is measured to be 243(2) ps for 1173–1332 keV $\gamma$-ray energies. The measured time resolution is compared with the best values reported for different sizes of LaBr₃(Ce) scintillators coupled to various PMTs.