Optical ceramic scintillator for gamma-ray detection

Transparent lutetium oxyorthosilicate (LSO) ceramic was obtained with its scintillation properties rivaling those of single crystalline LSO. The transparent LSO ceramic was prepared by a nano-technology approach. Hot-isostatic-pressing (HIPing) was employed to densify the ceramic and eliminate porosity after sintering. Transparent polycrystalline LSO ceramics were obtained after the final HIPing. XRD examination confirms single monoclinic LSO phase. A light output as high as 30,100 ph/MeV was achieved under a ²²Na excitation source. LSO ceramic showed an energy resolution of 15% (FWHM) at 662 keV (¹³⁷Cs source) as well as a fast scintillation decay of 40 ns due to the 5d → 4f transition of Ce³⁺. The time resolution of the LSO ceramic (215 ps, FWHM) was found comparable to that of LSO single crystal (203 ps, FWHM).