Standardization of Rn-222 concentration using the multi-electrode proportional counter.

Standardization of the concentration of gaseous 222Rn based on a multi-electrode proportional counter (MEPC) is under development as a primary standard in Japan. In this study, the concept and evaluation of its performance are reported. The latter consists of a preliminary result for the uncertainty budget associated with the measurement of the MEPC and compensation of the electric field distortion in the MEPC. Moreover, an ionization-chamber-based gas circulation system was added for the calibration of radon monitors in the air. • Highlights paper 70 Furukawa et al.: • Standardization of the concentration of gaseous 222Rn based on a multi-electrode proportional counter (MEPC) is under development. • The relative standard uncertainty associated with the measurement of the MEPC was evaluated preliminarily to be 1.4%. • A new calibration system was devised that includes an inner-through-type ionization chamber as a transfer standard. [ABSTRACT FROM AUTHOR]