Study of the use of Electret Ion chambers as radom dosimeters in South Africa

Abstract

Radon is a naturally occuring radioactive gas which has been shown to be a major contribution to background dose. The underground mines in South Africa present a major occupational hazard. A need for cheap personal monitoring has been identified. In this thesis, commercially available electret ion chambers (EICs) are studied, with a view to use them as personal monitors. These detectors were developed to measure radon activity concentrations in houses. Their use in the harsh underground mining environments has shown some complications such as water entering the detectors and their response time to a rapid change in radon concentration has been questioned. Several measurements are discussed in this thesis relevant to solve these problems. Firstly, the EIC's are checked for accuracy in the laboratory using a radon source, as well as the radon chamber at the CSIR in Pretoria. Comparisons with alpha track detectors are also carried out.