New development of radon progeny measurement method based on alpha-beta spectrometry

Accurate measurement of radon progeny concentration is important for the dose assessment of radon exposure and the study of radon progeny behaviours. For measuring ²¹⁸Po, ²¹⁴Pb and ²¹⁴Bi concentration as well as EEC with high sensitivity, an alpha-beta spectrometry method was developed and applied in a step-advanced filter radon progeny monitor. The derivation details of this method is given in this paper and the uncertainty is discussed. The comparison experiments are carried out in radon chamber and in field. Results show that the alpha-beta spectrometry method can give ²¹⁸Po, ²¹⁴Pb and ²¹⁴Bi concentration as well as EEC with high sensitivity either for 60 min or for 30 min cycle, which leads to low uncertainty. This method can be used as a reference method for radon chamber and is suitable for portable radon progeny monitor. (authors)