Benchmark Positron and Electron Impact Ionization Studies on Model Collision Systems.
- Chief Supervisor
- Professor B. Lohmann
- Supervisors
- Dr. James Sullivan
- Professor S. Buckman
- Centre Research Nodes
- Adelaide and ANU
Ionization is a fundamental collision process that plays an extremely important role in astrophysics, atmospheric physics, plasma physics and radiobiology. This project will use both positrons and electrons to explore the impact ionization process on benchmark atomic and molecular targets like helium and argon, molecular hydrogen and molecular nitrogen. These fundamental experimental studies will provide new data to test the most modern theoretical approaches which have been developed to explain the ionization process.
Both positron and electron experiments will be carried out on the positron beamline facility at the ANU and will concentrate on high precision studies of the near-threshold region single and double ionization of the target atoms and molecules. Helium will be a particular target of interest in order to test the various, semi-classical theories of near-threshold ionization, including the Wannier threshold law, for both electrons and positrons. Other detailed electron experiments will be carried out at the University of Adelaide and will be directed at exploring electron impact ionization of rare gas targets and molecules of technological relevance such as C60, with fully determined kinematics. These experiments will utilise a coincidence spectrometer equipped with a magnetic angle changer to enable observations of kinematic regions which were previously inaccessible.
