Physical and geometrical parameters controlling measurements of radon emanation and exhalation from soil

A F Saad; R M Abdallah; N A Hussein

doi:10.1016/j.apradiso.2018.03.022

Physical and geometrical parameters controlling measurements of radon emanation and exhalation from soil

Appl Radiat Isot. 2018 Jul:137:273-279. doi: 10.1016/j.apradiso.2018.03.022. Epub 2018 Mar 29.

Authors

A F Saad¹, R M Abdallah², N A Hussein²

Affiliations

¹ Physics Department, Faculty of Science, University of Benghazi, Benghazi, Libya; Physics Department, Faculty of Science, Zagazig University, 44519 Zagazig, Egypt. Electronic address: afsaad@zu.edu.eg.
² Physics Department, Faculty of Science, University of Benghazi, Benghazi, Libya.

PMID: 29684632
DOI: 10.1016/j.apradiso.2018.03.022

Abstract

The influence of physical and geometrical parameters, such as grain size, volume of the emanation container and mass of the sample, on the emanation coefficient and exhalation rates of radon (with and without consideration of back diffusion effect and effective volume of the emanation container) released from soil have been investigated. Moreover, a method for assessing the flux of radon migrate through soil layers was proposed. This method is based on measurement of the cumulative radon concentration transmitted through five layers of soil. The transmission factor results from the decay of ²²²Rn over a period of 60 day required for it to migrate through these layers was also determined. The soil samples were collected from Al-Marj city located in northeastern Libya. Radon measurements were carried out by using a closed emanation container based on CR-39 nuclear track detectors (NTDs). The results showed that the radon emanation coefficient clearly increases with grain size, container volume and sample mass. The exhalation rates also increase with grain size and sample mass, but the container volume parameter shows an opposite trend. The radon flux and its transmission factor are significantly decreased throughout that uniform soil when the increase in soil depth retarded exhalation. This study shows that various physical and geometrical parameters were demonstrated to be greatly affected on the emanation coefficient and exhalation rates of radon released from soil.

Keywords: Back diffusion; CR-39 NTDs; Emanation coefficient; Emanation container volume; Exhalation rates; Grain size; Radon; Sample mass; Soil; Transmission factor.