Plasma-material interactions (PMI) will decisively determine the availability and thus the economy of a fusion reactor because of their impact on the lifetime of the first wall (erosion and deposition) and on safety (tritium retention and dust production).
In view of plasma-material interactions in future fusion devices such as ITER and a demonstration reactor DEMO, new challenges have to be met: extended operational regimes with respect to particle and heat flux densities onto plasma facing components, both steady-state and transient, the use of toxic first wall materials (Be in ITER), the presence of Tritium, the impact of neutron irradiation onto first wall materials and synergistic effects of the above mentioned operational conditions in fusion reactors.
At Forschungszentrum Jülich, linear plasma devices and heat flux test facilities are used to tackle these challenges. We describe both experimental and modelling capabilities and report on recent findings on material erosion and fuel retention in first wall materials such as tungsten, reduced activation steels and beryllium.
Advanced material concepts for tungsten such as tungsten – tungsten fibre composites and self-passivating smart alloys are investigated to overcome critical issues related to brittleness and surface oxidation of tungsten. We will discuss initial PMI experiments using advanced materials and future plans.