Fusion energy promises millions of years of clean energy. It has been identified that a deeper understanding of the science and technology of materials under extreme conditions is critical to the success of steady-state plasma fusion reactors. Plasma-facing materials in fusion reactors must be capable of withstanding large heat loads (up to 10 MW/m²) due to energetic charged and neutral particle bombardment (eV to keV), as well as the high-energy neutron flux (14.1 MeV) created by the fusion reactions. Some materials might erode or degrade quickly, requiring frequent replacement; others might eject excessive material into the plasma, contaminating it and leading to cooling of the burning plasma. Concerns over fuel inventory in plasma-facing materials, and consequently radiation safety, as well as material erosion affecting machine integrity, necessitate a better understanding of the complex plasma-material interactions and their interdependencies. Plasma-surface science is therefore crucial to the success of generating fusion power under steady state conditions.

This talk aims to give an introduction to the challenges of plasma-surface interactions in a fusion reactor. In our work we are integrating plasma exposure and ion beam techniques with advanced material and plasma characterisation diagnostics to understand material performance under high-flux fusion relevant conditions. Recent results will be presented, which includes deuterium retention and erosion studies of tungsten, graphite and diamond samples. The influence of high-energy ion beam interactions on these materials, which serve as a proxy for neutron irradiation, is also investigated. Materials are characterised using a range of techniques including positron annihilation spectroscopy, SEM, elastic recoil detection analysis and also techniques available at the Australian Synchrotron. Plasma characterisation includes both spectroscopic and laser-based diagnostics.

Cormac Corr is an ARC Future Fellow and leader of the Plasma-Surface Interaction group within the Plasma-Research Laboratory at the ANU. Cormac obtained a first class honours degree in Applied Physics (1999) and a PhD (2003) titled "A study of instabilities in electronegative rf-driven discharges" from Queens University Belfast  (Belfast, Northern Ireland). After his PhD, Cormac spent three years working at Ecole Polytechnique in Paris. He commenced work at the ANU in 2006. Cormac has undertaken a wide variety of laboratory plasma research with particular emphasis on combined experimental/modelling studies. Current and previous research activities are radio-frequency plasma discharges, plasma-surface interactions, negative ion plasmas, plasma stability, plasma waves, plasma processing, and plasma diagnostics.

Refreshments will be held in the Tea Room after the Seminar