Development of an on-line hybrid electronic radiation dosimeter for a mobile robot using pMOSFET and SiC diode

This paper describes the development effort of a hybrid electronic radiation detector/dosimeter using a SiC diode and a p-type power MOSFET. To select the best candidate for the dosimeter among commercial devices, we have investigated the radiation performance of the devices in two Co-60 irradiation facilities in Korea. As a result of the investigation, two semiconductor sensors with excellent proportionality to incident radiation were identified. A small hybrid radiation-detection/dosimetry module with the two sensors has been developed. The real-time detector module is also radiation hardened for an ionizing radiation environment with well over 100 krad (SiO2) dose. The developed small and simple semiconductor electronic dosimeter is unique in terms of its extended dose range (∼100 krad), dose-rate (50 rad/hr ∼ 8 krad/hr) capability, and its level of redundancy/diversity along with its size/weight.