Comparative study of Lu3Al5O12:Pr3+ and Bi4Ge3O12 crystals for gamma – ray detection.

Abstract: The scintillation response of Lu3Al5O12:Pr3+ (LuAG:Pr) single crystal was investigated and compared to the response of a reference Bi4Ge3O12 (BGO) crystal for gamma ray energies ranging from 32 to 1,274.5 keV. The light yield and energy resolution were measured using photomultiplier tube (XP5200B PMT) readout. For 662 keV gamma rays (137Cs source), an energy resolution of 6.5% obtained for LuAG:Pr is much better than that of 9.0% obtained for BGO. The light yield non-proportionality and energy resolution versus energy of gamma rays were measured and the intrinsic resolution of the crystals was determined after correcting the measured energy resolution for PMT statistics. The LuAG:Pr showed a good proportionality of the light yield within 5% over the energy range from 1,274.5 keV down to 32 keV, which is much better than that of 14% for BGO. The photofraction was determined at 662 keV for both crystals and compared with the ratio of the cross-sections for the photoelectric effect to the total one calculated using WinXCOM program. [Copyright &y& Elsevier]