A novel inorganic scintillator: Lu2Si2O7 :Ce3+ (LPS)

We have characterized the gamma and X-ray scintillation properties of Ce³⁺ doped Lu₂Si₂O₇, a lutetium pyro-silicate (LPS) material. The rare earth ions are located in an octahedral site with C₂ symmetry. The compound exhibits chemical stability, transparency in a wide optical range and congruent melting, which allows growing of single crystals of good optical quality. The melting temperature is about 2000°C, slightly lower than that of Lu₂SiO₅ (LSO). Two maxima at 305 nm and 355 nm are observed in the optical absorption spectrum. The emission spectrum of Ce³⁺ in LPS shows a broad band peaking at 380 nm. For nominal Ce³⁺ atomic concentrations in the range 0.005-0.01, the light yield varies in the range 13,000-23,000 photons/MeV under gamma-ray excitation. The actual cerium concentration inside the crystal still needs to be determined. The scintillation decay time is around 30 ns and, in the first studies, neither a long component nor afterglow was observed