Applications of electret and radon-box in the estimation of radon concentration

This work describes a technique for accurate radon and thoron associated measurements in the environment, This technique is called electret technology. The theory of such technology is described in detail. Also, it describes the radon/thoron calibration facility designed and constructed for the first time through the radiation safety program of Atomic Energy Authority in Egypt. It is called a radon/thoron box. The use of the radon/thoron box is very simple either for system calibration or in measurement for different radioactive gases. Radon/thoron gas is injected into one side of the radon/thoron glass box and exhausted from it through the opposite side. The residence time of the radioactive gases in the container can be varied as well by changing the inlet and exhaust flow rates. During the time the radioactive gases stay in the box, they decay into their short-lived daughter products. The radon/thoron box atmosphere can be controlled within a wide range of condition including radiation levels, electric charge concentration, relative humidity, and temperature. In this study, it is found that the radon concentration varies with time as a power function: Rn con=4.7127T ^0.7258, R²=0.9478