Measurement of mixed radon and thoron daughter concentrations using alpha and beta activities filtered from air

This paper presents a detailed study of integral four- and five-count filter methods for the measurement of mixed radon and thoron daughter concentrations in air. The four-count method utilizes beta activity measurement while the five-count method is based on alpha activity measurement with plastic track detectors. A good correlation between the two independent detection techniques has been observed. An adequate theoretical framework is provided by interpreting the observed data.