Development of a Field Emission Image Sensor Tolerant to Gamma-Ray Irradiation

A field emission image sensor (FEIS) that consists of a field emitter array (FEA) and a cadmium telluride-based diode was proposed for use in the nuclear decommissioning of the Fukushima Daiichi nuclear power plant. FEAs and cadmium telluride/cadmium sulfide diode were irradiated with γ-rays for a dozen times, each with a dose of irradiation of 100 kGy, until the accumulated dose of irradiation reached 1 MGy. Electron emission properties of the FEAs and the photovoltaic properties of the cadmium telluride/cadmium sulfide diode were evaluated after each irradiation. Neither the FEAs nor the cadmium telluride/cadmium sulfide diode showed significant deterioration in their current-voltage characteristics. A test tube of FEIS consisting of an FEA and cadmium telluride-cadmium sulfide diode showed a photo-detection performance both before and after the γ-ray irradiation to the dose of irradiation of 1 MGy.