Scintillation properties of LuAG:Pr grown by Furukawa Co. Ltd., Japan, have been studied. The best crystals display light outputs up to 19000 ph/MeV and an energy resolution of 4.6% at 662 keV. The scintillation yield is found to be a function of size and temperature of the sample; it can be enhanced by 40% upon heating to 450 K. Radioluminescence spectra show both -and -transitions of Pr 3+ ions; the contribution of the latter increases with temperature. The scintillation decays are complex, with a fast decay constant of 20 ns. The presence of 176 Lu induces high background activity.

Abstract-In this paper we present the studies performed on a set of Lu 3 Al 5 O 12 :Pr (LuAG:Pr) crystals with praseodymium concentration between 1.5 and 10%, grown by the micro-pulling-down ( PD) technique. The research comprises the measurements of X-ray excited emission spectra and 137 Cs gamma-ray pulse height spectra in a range from 78 to 600 K, and thermoluminescence glow curves. Based on experimental data we discuss the dependence of scintillation properties of Lu 3 Al 5 O 12 :Pr on praseodymium content and temperature. The main attention is focused on a distinct increase of scintillation yield with temperature, which we attribute to existence of shallow electron traps and their temperature-dependent contribution to scintillation of LuAG:Pr. An active role of traps is demonstrated by a novel experiment combining X-ray and laser excitation.