Researchers have uncovered how positrons – key to PET scan technology – interact with molecules, paving the way for further research that may advance materials science and medical imaging technology.

Antimatter is typically regarded as rare and exotic – often found in sci-fi novels and films such as Angels and Demons, Star Trek – but antimatter is abundant in our galaxy. It is readily available in labs around the world with important use in materials science, medical imaging and testing fundamental laws of physics.

Medical imaging technology

Understanding antimatter interactions with molecules is an extremely challenging theoretical problem. It must be solved if scientists are to advance fundamental research and applications in medical imaging technology and material science. 

In a major advance, researchers from Trinity College Dublin and Queen’s University Belfast worked in collaboration to develop a powerful theoretical and computational approach that has successfully explained more than 20 years’ worth of measurements, which can be used to predict how positrons interact with other molecules. Their breakthrough research has been published in the leading journal, Nature.

Dr Charles Patterson from the School of Physics at Trinity developed the Exciton software that he and the Queen’s University group adapted – creating Exciton+ – to perform the calculations in the work. He said: "I developed the Exciton code over many years to enable me to study how materials absorb and emit light for applications such as light emitting diodes and solar cells.

"I am delighted that Dermot Green and his group were able to adapt the code to study how positrons interact with molecules. Many-body physics is a fascinating area of research with many important applications."

'A formidably complex area of research and science'

The research was led by Dr Dermot Green from the School of Mathematics and Physics at Queen’s, who said: "Until now, scientists have struggled to properly explain how antimatter interacts with molecules – it is a formidably complex area of research and science.

"Our breakthrough provides fundamental understanding of these interactions, unprecedented accuracy, and the ability to make predictions, which may help support fundamental physics and develop antimatter-based applications in materials science and medical imaging."

The research was funded by a European Research Council grant ANTI-ATOM. The team of researchers included Jaroslav Horfierka (Queen’s University PhD student and joint-first author), Brian Cunningham (Queen’s University Research Fellow and joint-first author), Charlie Rawlins (Queen’s University Research Fellow) and collaborator Dr Charles Patterson from Trinity College Dublin.