DISTRIBUTION OF ALPHA PARTICLE TRACKS ON CR-39 DETECTOR IN RADON DIFFUSION CHAMBER

Abstract

The purpose of this study was to study the spatial distribution of traces of alpha particles formed by radon and its descendants in the diffusion chambers of radon. Three cylindrical chambers equipped with CR-39 detectors were used, the radon concentration was estimated using the RAD7 device. Registration revealed an uneven distribution of traces of alpha particles on the surface of the detector, the density of traces near the camera walls was 30% lower than in the center. These results were the opposite of analytical predictions based on the same camera dimensions. The critical angle of detection relative to the particle incidence energy was determined using the Track_vision software, which showed a significant effect of camera size and critical angle on the distribution of track density. In addition, the study examined the sources of changes in track density by analyzing partial contributions of volumetric and sedimentary fractions of radon and its descendants. There was an increase in the sidewall share, and with an increase in the radial distance from the detector Center, the volume and platform share decreased. Changing the dimensions of the camera affected the relative effects of these partial contributions, resulting in different distributions of visible traces on the detector's surface. The experimental results were compared with the values obtained using previously developed software based on the Monte Carlo method. Five different expressions of the detector response function were used, two of which greatly underestimated the results of the experiment. This comprehensive study sheds light on the complex dynamics of alpha particle propagation paths in radon diffusion chambers and highlights the importance of accurate modeling for reliable estimation of radon concentrations.