Intrinsic resolution of ceramic YAG(Ce), GYAG(Ce), and YAG(Ce,Nd) scintillators

We developed transparent ceramic scintillators of Ce doped YAG, Ce and Nd codoped YAG, and Ce doped (GdY)AG, respectively. We cut them with a size of 5 times 5 times 5 mm³ for Ce:YAG and (Ce,Nd):YAG, and 5 times 5 times 2 mm³ for Ce:GYAG. At three temperature conditions, such as +20, 0, and -20degC, a temperature dependence of a light yield are measured, when they are coupled with avalanche photo diode, which is a S8664-55 type APD manufactured by Hamamatsu photonics. In these conditions, light yield of them turned out to be ~0.4, ~0.1, and ~0.25 times as large as that of Tl:CsI crystal. All of them show little temperature dependence of less than 10% in this 40 K temperature change. By measuring circuit noise and statistical noise due to excess noise factor of APD measurement system, we also study the temperature dependence of intrinsic energy resolution of these scintillators, in the range of 60 to 1400 keV. There are little temperature dependence observed, and it turned out to be about 5% at several hundreds keV.