Flux Density and Dose Rate of Gamma-Rays Due to Atmospheric Radon Daughters : Results of Monte Carlo Calculation

The Monte Carlo calculations are carried out for estimating the flux densities and the dose rates of gamma-rays near the ground surface due to the short-lived radon daughters in the atmospheric layers of various elevations. When the radon daughters are distributed uniformly in the atmosphere and their contents are same each other, the flux density due to 214Bi is about 2.7 times higher than that of 214Pb, and the dose rate of the former is about 6.8 times of the latter. The results obtained in this work are available to estimate the flux densities and the dose rates due to the atmospheric radon daughters in any arbitrary vertical distribution