Controlled fusion - a process seen in stars like our Sun, provides an inexhaustible energy source. At the same time, harnessing fusion energy in a power plant is an ultimate physics and engineering challenge. For instance, materials facing hot plasma in a power plant must withstand extreme power loads often reaching 20 MW/m 2 . Tungsten is presently used in most modern fusion facilities and is foreseen for a power plant. However, the harsh environment of a power plant can limit the lifetime of tungsten components. Therefore, options must be explored to coat the existing plasma-facing materials with tungsten or to "repair" the damaged tungsten elements in a fusion device directly, without removal of a damaged component.
The present work is aimed at investigating tungsten coatings produced using the plasma spray technology at Forschungszentrum Jülich. The work will comprise investigations of coating integrity, microstructure, porosity, and adhesion to the substrate. Optical and electron scanning microscopy, combined with a focused ion beam for 3D analysis, metallography and other techniques will be used in the study.
Further, the exposure of most stable and reliable coatings in realistic plasma environment should be conducted in the frame of the master thesis activity. Samples will be exposed to the stationary plasma in the unique linear plasma device PSI-2 at Forschungszentrum Jülich. The work will be performed in the close collaboration with the specialists of world-leading Jülich Thermal Spray Center.
This master thesis work is a part of a larger project on the development of a robotic system for tungsten coatings inside fusion devices. When successful, the system developed can be applied in the current most modern fusion devices worldwide, including the stellarator Wendelstein 7-X, the world's largest stellarator situated in Greifswald, about 200 km north from Berlin.
Prof. Dr. Andrey Litnovsky
Tel.: +49 (0)2461 61 5142
E-Mail: [email protected]
Institute of Energy and Climate Research
Plasma Physics IEK-4