Plasma-Wall Interaction in Fusion Devices

The group investigates the interaction of fusion plasmas with the walls in fusion devices.

The interaction of the hot plasma with the first wall is a key boundary condition for the operation of a fusion device. Energetic particles emitted from the plasma are both retained in the first wall and erode it. In a D/T fusion reactor the loss of T-fuel through retention is a significant  operational challenge, as T is a scarce resource that must be bred on-site from lithium within the reactor blanket. Additionally, eroded wall material can enter the plasma as impurity, leading to radiative cooling and consequently limiting energy confinement.

Erosion and fuel retention are extensively investigated in laboratory experiments under controlled conditions. Such experiments allow a better understanding of the underlying physical processes and the development of models to describe them. However, applying these models to predict the behaviour in future fusion reactors necessitates validating and integrating them through experiments conducted in current fusion devices. These devices operate under less controlled conditions requiring sophisticated integrated modelling to accurately interpret the experimental outcomes.

The Plasma Wall Interaction in Fusion Devices group addresses these challenges through comprehensive experimental and modelling approaches. We conduct targeted experiments in existing fusion devices and simultaneously develop and validate integrated simulation tools designed to predict erosion and fuel retention in future fusion reactors.

Our group operates a dedicated manipulator for exposure of samples and even of entire components to relevant conditions in the ASDEX Upgrade divertor. We are also involved in Experiments in W7X and analyze wall elements or entire components. The so obtained experimental results are subsequently interpreted using advanced integrated models of plasma impurity transport and mixed material formation on the first wall.