Novel dose rate monitoring for intense radiation fields based on cavity ring-down laser spectroscopy

To monitor dose rates in intense radiation fields, we are developing a novel dose rate monitoring method based on cavity ring-down laser absorption spectroscopy, where the dose rate of the radiation field can be derived from concentrations of the radiation induced chemical species in irradiated gas. We have attempted to verify the operational principle of this method through off-line/on-line measurements of ⁶⁰Co gamma-ray induced O₃ and NO₂ in air. The results of these experiments demonstrated that the present method is quite useful for dose rate monitoring in intense radiation fields with high radiation resistance, by showing the detectable range of an absorbed dose rate from 0.5 to 2000 Gy/s with a time resolution of about 30 s.