Abstract: [Problem] To provide a scintillator plate capable of improving the accuracy of radiation detection, and expanding the surface area for practical use while suppressing manufacturing costs, and also provide a radiation measuring apparatus, a radiation imaging apparatus, and a scintillator plate manufacturing method. [Solution] A scintillator plate (1) includes a scintillator (2) that generates scintillation light when excited by incident radiation. The scintillator plate (1) includes a scintillator layer (22) covered with scintillator powder (21) having an average particle diameter equal to or greater than the range of the radiation within the scintillator (2) when the radiation to be measured is either alpha rays, electron beams, or ion beams.

Abstract: [Problem] To provide a scintillator plate capable of improving the accuracy of radiation detection, and expanding the surface area for practical use while suppressing manufacturing costs, and also provide a radiation measuring apparatus, a radiation imaging apparatus, and a scintillator plate manufacturing method. [Solution] A scintillator plate (1) includes a scintillator (2) that generates scintillation light when excited by incident radiation. The scintillator plate (1) includes a scintillator layer (22) covered with scintillator powder (21) having an average particle diameter equal to or greater than the range of the radiation within the scintillator (2) when the radiation to be measured is either alpha rays, electron beams, or ion beams.

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 radioactive dust monitor comprising a dust collecting electrode serving also as a radiation detecting surface, an ionization line extending in air in a spaced relation with the dust collecting electrode and a radiation detection part. The radiation detection part is provided with a scintillator disposed close to said dust collecting electrode and a photoelectric conversion part converting light emitted from the scintillator into an electric signal. Dust in air is collected by the dust collecting electrode due to a corona discharge which is generated by applying a negative high voltage to the ionization line and by applying a positive high voltage to the dust collecting electrode, and light emitted from the scintillator due to radioactive rays radiated from the collected radioactive dust is detected by the photoelectric conversion part.

Abstract: A radioactive dust monitor comprising a dust collecting electrode serving also as a radiation detecting surface, an ionization line extending in air in a spaced relation with the dust collecting electrode and a radiation detection part. The radiation detection part is provided with a scintillator disposed close to said dust collecting electrode and a photoelectric conversion part converting light emitted from the scintillator into an electric signal. Dust in air is collected by the dust collecting electrode due to a corona discharge which is generated by applying a negative high voltage to the ionization line and by applying a positive high voltage to the dust collecting electrode, and light emitted from the scintillator due to radioactive rays radiated from the collected radioactive dust is detected by the photoelectric conversion part.

Abstract: An exhaust monitoring method for evaluating and monitoring a radioactive material concentration in exhaust by sampling the exhaust from radioactive materials handling facilities, collecting dust contained in the exhaust with an exhaust filter medium for monitoring, and performing the radioactivity measurement of the exhaust filter medium. The method is characterized in that a HEPA filter is disposed in an exhaust duct, the exhaust is sampled from the exhaust duct immediately after being filtered by the HEPA filter, and an exhaust sampling path is provided such that the sampled exhaust reaches the exhaust filter medium for monitoring within 20 seconds after passing through the HEPA filter, whereby a background for the radioactivity measurement is reduced. By performing the nuclide analysis of the exhaust filter medium, the abnormal/normal state of an exhaust path from the HEPA filter to the exhaust filter medium can be judged based on the presence/absence of the progenies of radon.