M. D. Birowosuto, P. Dorenbos, C. W.E. van Eijk, K. W. Krämer and H. U. Güdel
Scintillation Properties of LuI₃:Ce³⁺-High Light Yield Scintillators
IEEE Trans. Nucl. Sci. 52, 1114-1118 (2005)                 

Abstract: The scintillation properties of LuI₃:Ce³⁺ (pure, 0.5%, 2%, and 5% Ce³⁺), a new member of the generation of Ce³⁺ doped lanthanide trihalide scintillators, are presented. This material has a calculated density of 5.6 g/cm³ and an atomic number Z_eff of 60.2. Under optical and X-ray excitation, Ce³⁺ emission is observed to peak at 472 and 535 nm. A high light yield of 76000 photons per MeV (ph/MeV) was measured for LuI₃:2%Ce³⁺. LuI₃:Ce³⁺ 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 ± 0.5% was observed for LuI₃:0.5%Ce³⁺.