Japan Nuclear Cycle Development Institute

Kenji Izaki

Yasuhisa Ito

Hirohide Kobayashi

Nobuyuki Kanazawa

Ichiro Hasegawa

Kazuo Ino

Tadayoshi Yoshida

A ZnS (Ag) scintillation detector comprises a ZnS (Ag) scintillators layerwhich is excited by incident &#x3b1;-rays and emits a scintillator light, a photomultiplier tubewhich converts the scintillator light into an electric pulse signal, and a counting rate meterwhich counts the obtained pulse signal. The scintillator layer has a thickness which is not less than a range of &#x3b1;-rays from &#x3b1;-ray emitting nuclides (natural radioactive nuclides) to be separated, which enables energy absorption of &#x3b1;-rays from the &#x3b1;-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 circuitis 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.

ZnS(Ag) scintillation detector

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.

Radioactive dust monitor

Growing community of inventors

Naka-gun, Japan

Kenji Izaki