Patent ID: 8431042

Claim:
A solid state scintillator material, comprising: a composition represented by a general formula: (Gd 1-α-β-γ Tb α Lu β Ce γ ) 3 (Al 1-x Ga x ) a O b where, α and β are numbers satisfying 0<α≦0.5, 0<β≦0.5, and α+β≦0.85 (atomic ratio), γ is a number satisfying 0.0001≦γ≦0.1 (atomic ratio), x is a number satisfying 0<x<1 (atomic ratio), a is a number satisfying 4.8≦a≦5.2 (atomic ratio), b is a number satisfying 11.6≦b≦12.4 (atomic ratio); and a garnet structure, wherein the material contains Ba in a range of 10 to 200 mass ppm, and wherein a ratio (I p /I G ) of a maximum peak intensity I p of a perovskite phase with respect to a maximum peak intensity I G of a garnet phase by X-ray diffraction is 0.01 or less (including zero).