Positrons have been predicted to form a true bound state with various atoms, mostly metallic. The experimental investigation of this process has long been hampered by the lack of a positron beam of sufficient intensity and energy resolution to perform the experiments required to verify this phenomenon. This project will use the low energy, high resolution beamline at the Australian Positron Beamline Facility, part of the Centre for Antimatter-Matter Studies (CAMS), to perform the first experiments attempting to investigate this phenomenon.

Negative ions, where an electron binds to a neutral atom (or molecule), are common throughout atomic and molecular physics and play a crucial role in tmospheric physics, plasma physics, lighting, and biological processes. In the case of a poaitron, the antiparticle of the electron, the situation is quite different due to the different interaction between positrons and atoms. Theoretical calculations have predicted the binding of positrons to various metal atoms, however, and this project will work towards experimentally verifying the existence of such bound states.

The project will use a low energy, high resolution positron beam to study the interactions of positrons with metal vapour atoms. One way in which positron binding can be determined is by investigating low energy scattering cross sections with the desired target, and work will focus initally on this type of scheme. Interaction with top theorists in the field will also be a critical component to the success of this project. The student involved in this project will be expected to be self motivated and able to operate both independently and as a part of a team. General scientific and experimental skills will be developed, such as computer programming, experiment planning, equipment design, scientific writing and data analysis working with vacuum equipment and design and operation of metal vapour beams. The student will also gain a knowledge of atomic and molecular physics in general, and charged particle scattering and positron interactions in particular.