Patent ID: 7230248

Claim:
A ceramic scintillator provided with a sintered body of a lutetium oxysulfide phosphor containing as an activator at least one element selected from Pr, Tb and Eu, and having a composition substantially expressed by General formula: (Lu 1−a M a ) 2 O 2 S where M denotes at least one element selected from Pr, Tb and Eu, and a is a number satisfying 0.0001≦a≦0.2, wherein the sintered body of the lutetium oxysulfide phosphor contains an alkali metal element in a range of 5 ppm or more and 15 ppm or less and phosphorus in a range of 5 ppm or more and 40 ppm or less, and has a relative density of 99.5% or more.