Semi-automatic evaluation system for nuclear track detectors applied to radon measurements

A global semi-automatic evaluation system has been set up in our laboratory to scan and count etched tracks in both Makrofol-DE and LR-115 detectors. This methodology is, in principle, fully adaptable to any chemical and elec trochemical etched track detector. The main advantage it offers is a consid erable reduction of the counting time in comparison with the traditional me thods using optical devices - microscope or microfiche reader depending on the track size - and a wide detectable range. In addition, it yields accura te, reliable and quite reproducible results. It has been used to measure th e track density in both Makrofol-DE and LR-115 based radon and radon daught er detectors. A detailed description of this method is presented in this pa per. Results from a comparison study between this system and ocular countin g and from experimental calibration are presented as well. The corresponden ce between the results of the semi-automatic system and those obtained dire ctly with ocular counting has been found to be rather good. (C) 2001 Elsevi er Science Ltd. All rights reserved.