Sensitivity of a Combined Charcoal and Etched Track Technique for 222Rn

To describe the radon detection process of a new radon dosemeter, which is based on the simultaneous utilisation of activated charcoal and CR-39 etched track detector, a simple model was formulated. The dependence of the response of the dosemeter on exposure time, irradiation time of the detector foil, thickness of the charcoal layer, diffusion and the adsorption coefficients of radon in charcoal was calculated. The theoretical model was verified by experiments. It was found that for a short (one hour) exposure to a radon atmosphere the response can be as high as (900 tracks.cm-2.(kBq.m-3)-1.