Interaction between plasma and plasma facing materials is an issue of great importance for the safe operation of the fusion devices. Beryllium (Be) is a candidate material to be used in the main chamber of ITER and the future fusion devices based on magnetically confined plasma. Beryllium due to its low atomic number prevents the dilution of plasma and presents low fuel retention which is crucial for the life time of the wall and the conservation of the fuel. Moreover, beryllium is an oxygen getter which reduces oxygen impurities inside the vessel.

The objective of Pavlos Tsavalas’ PhD is the investigation of plasma facing material from the JET tokamak main chamber after the interaction with the plasma in order to assess material erosion, fuel retention and material deposition from other areas of the tokamak. In order to achieve this investigation, the following methods have been used:

1. Ιon beam analysis with deuteron (2H) and helium (3He) to detect, quantify and assess the depth profile of the light elements (deuterium, beryllium, carbon, nitrogen and oxygen) and the micro-beam to depict the mapping of the same elements on the surface.
2. Differential cross sections measurements of deuteron reaction on beryllium which are necessary for the quantitative results of the ion beam analysis.
3. X-Ray fluorescence to assess the relative concentration of the heavier elements (chromium, iron, nickel, molybdenum and tungsten) in the whole volume of the samples.
4. Scanning electron microscopy with energy dispersive spectroscopy of X-rays to investigate the mapping of the heavier elements and the morphology of the surface.
5. X-Ray diffraction to assess any compound formation in the samples.

The PhD thesis will be defended in at the School of Applied Mathematical and Physical Sciences of National Technical University of Athens.