A novel inorganic scintillator: Lu/sub 2/Si/sub 2/O/sub 7/:Ce/sup 3+/ (LPS)

Abstract

We have characterized the gamma and X-ray scintillation properties of Ce/sup 3+/ doped Lu/sub 2/Si/sub 2/O/sub 7/, a lutetium pyro-silicate (LPS) material. The rare earth ions are located in an octahedral site with C/sub 2/ 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/spl deg/C, slightly lower than that of Lu/sub 2/SiO/sub 5/ (LSO). Two maxima at 305 nm and 355 nm are observed in the optical absorption spectrum. The emission spectrum of Ce/sup 3+/ in LPS shows a broad band peaking at 380 nm. For a nominal Ce/sup 3+/ atomic concentration of /spl sim/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.