Scintillation properties of LuI/sub 3/:Ce/sup 3+/-high light yield scintillators

The scintillation properties of LuI/sub 3/:Ce/sup 3+/(pure, 0.5%, 2%, and 5% Ce/sup 3+/), a new member of the generation of Ce/sup 3+/ doped lanthanide trihalide scintillators, are presented. This material has a calculated density of 5.6 g/cm/sup 3/ and an atomic number Z/sub eff/ of 60.2. Under optical and X-ray excitation, Ce/sup 3+/ emission is observed to peak at 472 and 535 nm. A high light yield of 76 000 photons per MeV (ph/MeV) was measured for LuI/sub 3/:2% Ce/sup 3+/. LuI/sub 3/:Ce/sup 3+/ has a nonexponential decay time. The contribution of short decay components (within 50 ns) to the total light yield is around 50%. An energy resolution (full-width half maximum over peak position) for the 662 keV full energy peak of 4.7/spl plusmn/0.5% was observed for LuI/sub 3/:0.5% Ce/sup 3+/.