The scintillation response of YAlO3:Ce (YAP:Ce) and Lu0.7Y0.3AlO3:Ce (LuYAP:Ce) crystals with same size
of 10 10 5mm3 were studied for gamma ray energies ranging from 22.1 to 1274.5 keV. The light
yield, its non-proportionality and the energy resolution were measured with the photomultiplier tube
(PMT). The intrinsic resolution of the crystals versus energy of gamma rays has been determined after
correcting the measured energy resolution for photomultiplier tube statistics. For 662 keV gamma rays
(137Cs source), the YAP:Ce showed the light yield of 32,000 ph/MeV,which is much higher than that of
9800 ph/MeV obtained for LuYAP:Ce. The energy resolution of 4.4% obtained for YAP:Ce is much better
than that of 7.9% obtained for LuYAP:Ce, due to its much higher light yield and better intrinsic resolution.
The scintillation light loss of tested crystals at 511 keV gamma rays (22Na source) was also presented. The
estimated photofraction was determined for both crystals and compared with the cross-sections ratio
calculated using WinXCom program. The experimental results of the total mass attenuation coefficients
for both crystals are in good agreement with the theoretical values, within the experimental uncertainty.