INVESTIGATION OF SOME SCINTILLATION PROPERTIES OF YAG-CE CRYSTALS

A light output expressed in the photoelectron (phe) number, a relative light yield for alpha-particles and light pulse shapes for gamma-rays and alpha-particles excitation of the YAG:Ce crystals with different Ce doping between 0.012 and 1.08 mol% were studied. The highest light output of 1420 +/- 70 phe/MeV was measured for the sample doped with 0 .21 +/- 0.03 mol% Ce, while the fastest pulse was observed for the sam ple doped with 1.08 +/- 0.08 mol% Ce showing, however, lower light yie ld by 10%. The relative light yield for alpha-particles of 0.21 +/- 0. 03 as compared to gamma-rays was approximately the same for all the sa mples studied. In conclusion, the YAG:Ce crystal doped with about 1 mo l% of Ce is the most appropriate for different applications. For this crystal the alpha-gamma discrimination by digital charge comparison me thod was studied. A clear separation was observed with the YAG crystal coupled to the XP2020Q photomultiplier for 5.49 MeV alpha-particles f rom Am-241 source and 6.04 MeV as well as 8.77 MeV from ThC source. Ho wever, this separation was inferior compared to that known for CsI(Tl) .