Measurements of size distribution of naturally occuring radioactive aerosols by a diffusion battery method

Measurements of the size distribution of naturally occuring radioactive aerosols (short-lived radon daughters) have been carried out by a diffusion battery method in a tunnel. Three kinds of analytical methods-log-normal method, response matrix method, and graphical stripping method-were applied to the estimation of a size distribution from observed relationships between radioactivity and flow rate. The activity distributions obtained were almost equal in form and also equal to those which were estimated from non-radioactive particle size distributions measured simultaneously. (author)