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 a nominal Ce³⁺ atomic concentration of ~0.01, under gamma-ray excitation we observe light yields in the range 13000-23000 photons/MeV, depending on the preparation atmosphere. 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