School Seminar Program
The Many Uses of Positrons
Dr James Sullivan
Atomic and Molecular Physics Laboratories
Positrons, predicted by Dirac in 1928 and discovered by Anderson in 1932, were our first glimpse into the world of antimatter. Since then, the study of positrons has evolved and now covers areas of fundamental and applied research, as well as being the key element of the medical imaging technique, Positron Emission Tomography (PET). Experimentally, positrons can be difficult to work with, being far less abundant than their matter counterpart, the electron, as well as due to their tendency to annihilate on contact with those same electrons. This has somewhat limited the growth and application of the field. Here at the ANU, we have built two positron beamlines to perform fundamental quantum scattering experiments and to undertake analysis of material structure. This talk will cover a little of the early history of positrons, and their uses in science and technology. The construction and operation of the two beamlines will be explained, as well as the experimental techniques used. Some recent results will also be presented, from the main areas of research undertaken in our laboratory.
Dr James Sullivan studied undergraduate physics at the ANU, and after a brief hiatus returned to undertake his PhD studies at RSPhysSE. After graduating in 1999, he took up a postdoctoral fellowship at the University of California, San Diego, where he worked on positron experiments in the laboratory of Prof. Cliff Surko. At the end of 2001, he took up a JSPS postdoctoral fellowship at the Photon Factory, in Tsukuba, Japan, and then was awarded an Australian Research Fellowship to establish the positron physics program at ANU, commencing in 2004. Since that time, he has been working within RSPE, and has now established an active positron-based research program, covering atomic and molecular physics, materials science and medical physics.
Refreshments will be held in the Tea Room after the Seminar (around 5pm)