INDOOR RADON DAUGHTER CONTAMINATION MONITORING - THE ABSOLUTE EFFICIENCY OF CR-39 TAKING INTO ACCOUNT THE PLATEOUT EFFECT AND ENVIRONMENTAL-CONDITIONS

In this work it is shown that CR-39 (Supergrade PM355, Pershore Mouldi ngs Ltd, England) can be used as an absolute detector in Rn-222 and ra don daughters (RD) monitoring by employing it as an alpha spectrometer . By adopting the technique described here, one can measure separately : (a) the Rn-222 activity, (b) the RD alpha activity in the air, and ( c) the RD alpha activity plated out on the detector surface. The calib ration factors measured for these three items were found to be weakly dependent on environmental conditions. The relationship between die tr ack density and the radon and daughters alpha activity taking into acc ount the influence of the plateout phenomenon and environmental condit ions is discussed. Possible applications of the experimental results o n subjects related to dose calculation, like the mean RD deposition ra tes indoors, are also discussed.