Medical Physics and Biomedical Engineering


Radiation Physics Research Group

Pixellated diffraction signatures

Radiation Physics Group

The group activity is concentrated in four major themes:

  • Development of novel imaging systems for both photons and particles
  • Development of new sensors and sensor applications
  • The study of scattered radiation fields for tissue and material characterisation
  • Modelling schemes for radiation transport

Our aspiration is to develop novel, quantitative systems for X-ray, gamma-ray and other particle detection so that the maximum amount of information is extracted during processes of imaging and analysis. The holy grail of imaging systems is not only to detect and display structures and features within the imaged object but to be able to characterise them at the molecular or atomic level. Our research effort is focussed towards achieving that goal. Studying the diffracted and multi-scale scattered fields generated by our novel imaging geometries allows us to study tissue and other materials at an unprecedented structural detail for objects of real-world dimensions. We use and are involved in the development of state-of-the-art sensors to ensure we have maximum sensitivity to the different radiation probes used in our studies. X-ray imaging sensors with an exceptionally high dynamic range have enabled studies such as image-guided diffraction, in which areas of interest seen under standard X-ray imaging can be further probed at the molecular level using X-ray diffraction — all with the same detector. The use of sensors with energy resolving pixels have allowed us to develop a diffraction system with a step change in capability in terms of acquisition times and characterisation of the material. We also research new imaging systems using novel geometries - high energy time-of-flight imaging where limited access restricts the use of a conventional approach, and new tomographic techniques using a combination of optical and X-ray images to overcome challenging geometries. We have built detector systems for pinpointing the location of radioactive isotopes using the shape and motion of the active detector components and the use of photon/particle kinematics to solve directionality through scattering events. We also develop dual energy approaches for material characterisation in microCT; this technique has been used for the identification of osteoporosis by the 3D mapping of bone composition.

Application areas of current interest include breast cancer diagnosis and patient management, counterfeit and illicit drug identification, border security, new sensors based on graphene or compound semi-conductors, mapping mixed photon/neutron fields in proton therapy and SNM detection, damage in composite materials and bone structure.