Ceramic scintillator, method for producing same, and x-ray detector and x-ray CT imaging equipment using same

A ceramic scintillator having an improved optical output characteristic, comprising a sintered body of a rare earth oxysulfide and a rare earth oxide phase including Gd2O3 formed on the surface of said sintered body, said ceramic scintillator being produced by:

• placing the sintered body and a sulfide capable of generating at least one of SO2 and SO3 in a substantially sealed container containing oxygen;
• heat-treating said sintered body and the sulfide inside said container at a temperature of 900 to 1,200° C.;
• and
• abrading the surface of said sintered body, which has been taken out of said sealed container and on which the rare earth oxide phase and an oxysulfide phase have been deposited.

An X-ray detector comprising:

• a collimator for regulating the incident direction of X-rays;
• a scintillator block including ceramic scintillators arranged via reflectors;
• and
• a photoelectric transducer part having photodiodes, each of which corresponds to one of said ceramic scintillators of said scintillator block,
• each of the ceramic scintillators comprising a sintered body of a rare earth oxysulfide, and a rare earth oxide phase including Gd2O3 formed on the surface of said sintered body,
• each of the ceramic scintillators being produced by:
• placing the sintered body and a sulfide capable of generating at least one of SO2 and SO3 in a substantially sealed container containing oxygen;
• heat-treating said sintered body and the sulfide inside said container at a temperature of 900 to 1,200° C.;
• and
• abrading the surface of said sintered body, which has been taken out of said sealed container and on which the rare earth oxide phase and an oxysulfide phase have been deposited.

An X-ray CT imaging equipment comprising:

• an X-ray tube for emitting at a predetermined angle;
• an X-ray signal converting unit comprising several tens of X-ray detectors which include collimators, scintillator blocks, and photoelectric transducer parts for detecting said X-rays emitted from said X-ray tube through an object to be picked up;
• a computer for data accumulation and processing of electric current signals outputted from the photoelectric transducer parts;
• and
• a display device for displaying an image reproduced by the processing carried out by said computer,
• said ceramic scintillator block of said X-ray detector comprising a plurality of ceramic scintillators,
• each of the ceramic scintillators comprising a sintered body of a rare earth oxysulfide, and a rare earth oxide phase including Gd2O3 formed on the surface of said sintered body, each of the ceramic scintillators being produced by:
• placing the sintered body and a sulfide capable of generating at least one of SO2 and SO3 in a substantially sealed container containing oxygen;
• heat-treating said sintered body and the sulfide inside said container at a temperature of 900 to 1,200° C.;
• and
• abrading the surface of said sintered body, which has been taken out of said sealed container and on which the rare earth oxide phase and an oxysulfide phase have been deposited.