Measurements of the Distribution And
QUEENSLAND UNIVERSITY OF TECHNOLOGY SCHOOL OF PHYSICAL AND CHEMICAL SCIENCES MEASUREMENTS OF THE DISTRIBUTION AND BEHAVIOUR OF BERYLLIUM-7 IN THE NATURAL ENVIRONMENT Che Doering B. App. Sc., M. App. Sc. A thesis submitted in partial fulfilment of the requirements of the degree of Doctor of Philosophy 2007 i KEYWORDS Beryllium-7, environment, environmental radioactivity, radionuclide, cosmogenic, cosmic- rays, atmosphere, deposition, soil, surface air, atmospheric transport, erosion, depositional flux, areal activity density, Brisbane, Southeast Queensland, Australia ii ABSTRACT Beryllium-7 is a cosmogenic radionuclide produced in the atmosphere through the spallation of nitrogen and oxygen nuclei by cosmic-ray-produced neutrons and protons. It is carried in the atmosphere attached to aerosols and is deposited on land and ocean surfaces by wet and dry deposition processes. Beryllium-7 decays by electron capture to lithium-7 and has a half-life of approximately 53 days. It is a potentially useful radionuclide for studying different natural processes. This thesis presents a collection of scientific papers on the occurrence of beryllium-7 in the natural environment, particularly in the Southeast Queensland region of Australia. It shows the results of experimental measurements and discusses their implications. Overall, this thesis contributes to advancing our understanding of the distribution and behaviour of beryllium-7 in the natural environment and provides a foundation for the development of nuclear techniques for the evaluation of environmental problems. iii LIST OF PUBLICATIONS Doering, C., Akber, R., Heijnis, H., 2006. Vertical distributions of 210Pb excess, 7Be and 137Cs in selected grass covered soils in Southeast Queensland, Australia. Journal of Environmental Radioactivity 87, 135–147.
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