The present invention relates to a scintillator material comprising a scintillator host material doped with cerium. The scintillator host material is at least one of the group comprising i) garnets ii) CaGa 2 S 4 iii) SrGa 2 S 4 iv) BaGa 2 S 4 v) CaS vi) SrS; and the amount of cerium is controlled in the range 0.1 mol % to 1.0 mol %. The material may be used in gamma photon detection, in a gamma photon detector and as such in a PET imaging system.
