In the Positron Imaging Centre, positron-emitting radioactive tracers are used in interdisciplinary research involving a number of University groups and industrial sponsors.
Topics range from studying the fundamental physics of granular media to improving the processing of viscous non-Newtonian fluids in the food industry, from observing the percolation of liquids and gases through rock to optimising pharmaceutical processing.
The medical imaging technique of positron emission tomography (PET) has been adapted for these studies, and a new technique of positron emission particle tracking (PEPT) has been developed, by which a single labelled particle can be accurately tracked at high speed inside operating equipment.
Radioactive tracers are produced using our in-house cyclotron, and a continuous programme of research and development is devoted to extending the range of isotopes and forms available. Currently tracer particles down to 200µm in size are produced by ion exchange techniques. The tracers are detected using a positron camera comprising a pair of position-sensitive gamma ray detectors. A new positron camera has recently been installed, giving a factor of 20-improvement in sensitivity and count rate, which provides opportunities for further extensions to the imaging and tracking techniques. There are also plans to develop a simplified transportable PEPT system.