Properties of praseodymium and cerium doped Lutetium Aluminum Garnet (LuAG) were compared with cerium doped Lutetium Oxyorthosilicate (LSO) and Lanthanum Bromide (LaBr ₃ ). Light yield, its non-proportionality relative to 662 keV gamma -rays and the dependence of the energy resolution on energy of the detected gamma -rays were measured. LuAG:Pr turned out to have good proportionality, with deviation from unity around 10% at 16.6 keV and 3% at 59.5 keV. This, together with relatively high light yield of 5600 phe/MeV results in a very good energy resolution of LuAG:Pr of 5.1% measured with 662 keV gamma-rays. The measured time resolution of 308 ps is significantly larger than that of 166 ps obtained for LSO:Ce. This can be explained by smaller light yield of LuAG:Pr and the fact that only about 25% of its scintillation is emitted in short decay time modes of 17.6 ns and 52 ns, while the rest is decaying with long time modes of 1.4 mus and 9 mus.

!Scintillation characteristics of Y0.8Gd2.2(Al5-xGax)O12:Ce,Mg (x = 2.6 and 3) single crystals are presented. At 662 keV γ rays, the light yield of 35,600 photons/MeV obtained for Y0.8Gd2.2Al2Ga3O12:Ce,Mg is higher than that of 32,600 photons/MeV for Y0.8Gd2.2Al2.4Ga2.6O12:Ce,Mg. Scintillation decay components of 32.3 ns (52.4 %) + 104 ns (47.6 %) obtained for Y0.8Gd2.2Al2Ga3O12:Ce,Mg are faster than those of 11.5 ns (5 %) + 51.2 ns (69 %) + 302 ns (26 %) obtained for Y0.8Gd2.2Al2.4Ga2.6O12:Ce,Mg. Coincidence time resolution of 336 and 389 ps was obtained, respectively, for Y0.8Gd2.2Al2Ga3O12:Ce,Mg-PMT and Y0.8Gd2.2Al2.4Ga2.6O12:Ce,Mg-PMT, in coincidence experiment with a BaF2-PMT detector. The radioluminescence yield at room temperature (RT) is comparable for both crystals while the yield below 130 K is about 20% higher for Y0.8Gd2.2Al2Ga3O12:Ce,Mg. Afterglow and thermally stimulated luminescence (TSL) below RT are also measured.