Patent ID: 7301154

Claim:
An inorganic scintillator capable of producing scintillation by radiation, which is a crystal comprising a metal oxide containing Lu, Gd, Ce and Si and belonging to space group C 2 /c monoclinic crystals, and by simultaneously satisfying the conditions specified by the following inequalities (1) and (2), by outputting a fluorescent pulse, upon incidence of a radiation pulse to said inorganic scintillator, which is composed of a first fluorescent component exhibiting a fluorescent lifetime τ 1 and a second fluorescent component exhibiting a fluorescent lifetime τ 2 which is longer than the fluorescent lifetime τ 1 , and by simultaneously satisfying the conditions specified by the following inequalities (1) and (4), wherein { A Lu /( A Lu +A Gd )}<0.50 (1) 0.02 ≧{A Ce /( A Lu +A Gd )}≧0.002 (2) (τ2/τ1)≦8 (4) wherein A Lu represents the number of Lu atoms in said crystal, A Gd represents the number of Gd atoms in said crystal, and A Ce represents the number of Ce atoms in said crystal.