Nuclear Physics – Environmental Radioactivity Studies
The Physics Group operates the Environmental Radioactivity Laboratory (ERL). The ERL staff conduct research into the levels of radioactivity (natural and anthropogenic) in the environment. The main experimental techniques used are in-situ and laboratory-based gamma-ray spectroscopy. The in-situ measurements are made using a MEDUSA (Multi-element Detector for Underwater Sediment Activity) detector system which makes use of a CsI scintillator to detect gamma-rays and a GPS receiver to provide spatial information. The in-situ measurements are conducted on land and in underwater environments. The laboratory-based (high-resolution) measurements are conducted using a hyper-pure germanium detector (HPGe) which is encased in a 10 cm thick lead castle in order to reduce the room background.
The current focus is on the measurement of activity concentration of (primordial and anthropogenic) radionuclides in soils, sediment and water. Current research topics include: the exhalation of radon (an inert radioactive gas) from mine tailings dams, the correlation between radon levels in domestic dwellings and source terms (soil, building material), studies into the potential use of radiometry to partially characterize the terroir associated with vineyards, the systematic effects that impact on the measurement of activity concentrations, Monte Carlo simulation of the interaction of gamma-rays with detectors (for our geometries), the use of naturally occurring radioactivity to optimize minerals processing, studies of the impact of environmental radioactivity on ecosystems.