Study of radiation monitoring system based on fiber and pulsed-OSL technology

[Background] Optically stimulated luminescence (OSL) technology has recently been successfully used in the field of personal dosimetry, etc.. OSL detectors normally have the advantages of small size, strong anti-electromagnetic interference, anti-radiation, and wide dose linear range while detectors for traditional radiation monitoring system are large in size, susceptible to electromagnetic interference, and poor radiation resistance. [Purpose] This study aims to design a remote online radiation dose (rate) monitoring system based on OSL technology for diversity applications. [Methods] Al₂O₃: C was used as the radiation-sensitive material, with high sensitivity and long lifetime. Pulsed-OSL technology was adopted to ignore the high-intensity luminescence of the lens and fiber caused by laser exposure. Remote radiation monitoring was realized by using fiber to transmit stimulation light and OSL. The interference filter and absorbing filter were combined to block all reflected stimulation light. The OSL detector was located in the radiation field for performance test experiment, while other components were located outside the radiation field. [Results] Experimental results show that this radiation monitoring system has a dose measurement range of 79μGy ∼ 5 Gy, energy responses (60 keV ∼ 1.5 MeV, relative to ¹³⁷Cs) are within ± 25% of the air kerma measurement (with endcap of 1.5 mm Fe) and ambient dose equivalent measurement (with endcap of 0.1 mm Al), while the angular response is within ± 10% for 0° ∼ 135° (relative to 0°). [Conclusions] Radiation monitoring system based on fiber and pulsed-OSL technology has advantages of small-size detector, strong anti-electromagnetic interference, low detection limit, and wide measurement range, hence suitable for online real-time remote monitoring of dose (rate) in nuclear facilities such as nuclear power plant and nuclear power ship. (authors)