Abstract: A ZnS (Ag) scintillation detector comprises a ZnS (Ag) scintillators layer 22 which is excited by incident ?-rays and emits a scintillator light, a photomultiplier tube 16 which converts the scintillator light into an electric pulse signal, and a counting rate meter 34 which counts the obtained pulse signal. The scintillator layer has a thickness which is not less than a range of ?-rays from ?-ray emitting nuclides (natural radioactive nuclides) to be separated, which enables energy absorption of ?-rays from the ?-ray emitting nuclides to be separated to entirely occur in the scintillator layer, and which enables light shielding of the scintillator light generated in the scintillator layer by the scintillator layer itself to be neglected. A pulse height discrimination circuit 32 is further provided in a preceding stage of the counting rate meter. Thereby, the effect of the natural radioactive nuclides can be reduced and the contamination control can be efficiently and smoothly performed.

Abstract: A ZnS (Ag) scintillation detector comprises a ZnS (Ag) scintillators layer 22 which is excited by incident ?-rays and emits a scintillator light, a photomultiplier tube 16 which converts the scintillator light into an electric pulse signal, and a counting rate meter 34 which counts the obtained pulse signal. The scintillator layer has a thickness which is not less than a range of ?-rays from ?-ray emitting nuclides (natural radioactive nuclides) to be separated, which enables energy absorption of ?-rays from the ?-ray emitting nuclides to be separated to entirely occur in the scintillator layer, and which enables light shielding of the scintillator light generated in the scintillator layer by the scintillator layer itself to be neglected. A pulse height discrimination circuit 32 is further provided in a preceding stage of the counting rate meter. Thereby, the effect of the natural radioactive nuclides can be reduced and the contamination control can be efficiently and smoothly performed.

Abstract: A dose distribution-measuring method capable of grasping a three-dimensional form of an object to be measured or evaluating a three-dimensional dose distribution thereof. The method comprises providing a multiple-eye type radiation meter probe in which at least two directional radiation detectors are arranged so as to be spaced from each other and directed toward a point to be measured; and carrying out dose measurement by directing the radiation meter probe toward an object to be measured from different positions to thereby determine a three-dimensional dose distribution of the object to be measured. Each of the radiation detectors has a structure in which a periphery of the radiation detector main body, except for a detection surface thereof, is surrounded by a radiation shield to reduce the effect of radiation from other than the object to be measured and from Compton scattering.

Abstract: A directivity-type radiation detecting apparatus capable of detecting a particular radiation source or a moving situation thereof even in the high radiation atmosphere. A multiplicity of radiation detector probes are dispersedly arranged in different directions on an outer surface of a radiation shield. Alternatively, a multiplicity of penetration holes are dispersedly formed in different directions in a shell-shaped radiation shield and radiation detector probes are respectively disposed in the penetration holes of the radiation shield. The above-described directivity-type radiation detecting apparatus is used to compute and process a position and a direction of each radiation detector probe and a value measured by each radiation detector probe, whereby a position, a distribution situation or a moving situation of a radiation source is detected.

Abstract: A dose distribution measuring method capable of grasping a three-dimensional form of an object to be measured or evaluating a three-dimensional dose distribution thereof. The method comprises providing a multiple-eye type radiation meter probe in which at least two directional radiation detectors are arranged so as to be spaced from each other and directed toward a point to be measured; and carrying out dose measurement by directing the radiation meter probe toward an object to be measured from different positions to thereby determine a three-dimensional dose distribution of the object to be measured. Each of the radiation detectors has a structure in which a periphery of the radiation detector main body, except for a detection surface thereof, is surrounded by a radiation shield to reduce the effect of radiation from other than the object to be measured and from Compton scattering.