Novel multi-function polycarbonate/activated-carbon-fabric individual/environmental radon twin badges

摘要

In order to overcome some deficiencies of passive radon track detectors such as long-term exposures required, novel polycarbonate track detector/activated-carbon-fabric (PCTD/ACF) multi-function radon badges are introduced for individual and environmental monitoring. Two twin-badge designs are provided; A-Type and B-Type each having one badge with polyethylene (PE) filter allowing Rn-222 (3.82 d half-life) to pass while eliminating Rn-220 (55.5 s half-life) and one badge with no PE filter for detecting Rn-222 and Rn-220 simultaneously. In A-Type twin badges, each badge has a PCTD half bare and half with ACF layer while in B-Type twin badges, each badge has a PCTD fully covered with ACF layer. The ACF adsorbs radon on its carbon active sites and exposes the PCTD underneath to alpha particles at a higher rate than that in PCTD with no ACF; thus having a track density ratio >1, called amplification factor (AF). Each badge type either single or twin can be independently used, depending on the application. The radon badges can be applied in practice with a constant AF value of similar to 1.5 for concentrations up to 2.52 +/- 0.16 kBq.m(-3) as studied for long-term radon individual and environmental monitoring. It is concluded that the monitors developed can be applied in practice for individual and environmental monitoring for the concentrations studied up to 2.52 +/- 0.16 kBq.m(-3). It should be noted that this concentration is not to be considered as the upper limit concentration beyond which is under further studies.