A passive radon dosimeter based on the combination of a track etch detector and activated charcoal

The aim of this work is to test a combination of a Makrofol track detector with a new type of charcoal (Carboxen-564) to design a personal radon dosim eter. The intention is to use this dosimeter as a personal radon dosimeter to measure the monthly radon exposure in workplaces, especially when the oc cupancy is not exactly known. The proposed combination was exposed to low a nd high concentrations of radon in a large range of relative humidity (RH). For the optimal layer thickness,a charcoal bed of 2.2 mm, a specific track density of 5.1 tracks cm(-2)/kBq h m(-3) was obtained. For a monthly worki ng exposure(170 h) at an average radon concentration of 100 Bq/m(3), this m eans 87 tracks/cm(2) or 10 times the background of the Makrofol detector, w ith a statistical uncertainty of 15%.