NMIJ, Development of 222Rn primary standard using the proportional counter
Development of 222Rn primary standard using the proportional counter
News from Members - NMIJ
Radon (222Rn) is a naturally occurring radioactive gas and the largest contributor to public exposure to natural radiation. It is established that internal exposure to 222Rn increases the risk of lung cancer, leading to the availability of various radon monitors in the market designed to measure 222Rn activity concentration [Bq m-3]. At NMIJ, the standardization of gaseous 222Rn concentration is currently under development, using a Multi-Electrode Proportional Counter (MEPC) as the primary 222Rn standard. The measurement efficiency of the MEPC is influenced by the geometry of the radiation from 222Rn and its progenies. NMIJ has successfully used the MEPC to determine 222Rn concentrations provisionally. Moving forward, the focus will be on optimizing the measurement conditions of the MEPC to achieve higher accuracy through comparisons with other standards. Additionally, efforts will be made to establish a calibration system for radon monitors.
Reference: R. Furukawa et al., Appl. Radiat. Isot. 202, 111076, 2023
https://doi.org/10.1016/j.apradiso.2023.111076
Typical alpha spectrum obtained using the MEPC
Multi-electrode proportional counter
FURUKAWA Rio / HARANO Hideki
rio.furukawa@aist.go.jp / h-harano@aist.go.jp
