Efficiency Studies on Gd 3 Ga 3 Al 2 O 12 :Ce Scintillators: Simulations and Measurements

In gamma spectroscopy, apart from having high light output, good energy resolution, and timing resolution, it is the high efficiency (both detection and photopeak) of the detector which is of paramount importance. The high density (6.7 g/cm 3 ) and atomic number (55) of cerium-doped gadolinium gallium aluminum garnet (GGAG:Ce) scintillator make it a suitable detector for many applications. In this paper, we have carried out detailed realistic Monte Carlo simulations of absolute efficiencies (both total detection and photopeak) of GGAG:Ce scintillator for 137 Cs source and for different values of source-to-detector separation. Simulations were also made with different scintillators (LaBr 3 :Ce, NaI:Tl, CsI:Tl, BaF 2 , and SrI 2 :Eu) for comparison. In order to validate the simulations, we have made experimental measurements with GGAG:Ce, LaBr 3 :Ce, NaI:Tl, CsI:Tl, and BaF 2 detectors and compared with simulation results. A good agreement between simulation and measured results has been found.