Characterisation of W-Coatings for Fusion Applications (FUSION programa)

Main problem – is to understand physical phenomena of mechanical properties of W and to reduce the impurities in the main chamber:

• Mechanism of restructuring and surface relocations under high-flux irradiation at elevated temperatures.
• Material erosion by continuous or transient plasma ion and neutral impact, the subsequent transport of the released impurities through by the plasma and their deposition and/or eventual re-erosion constitute the process of migration.
• Due to erosion mechanism and re-deposition materials will interact on plasma facing surfaces.

The goal of the research is the fabrication of W films to be used in plasma-facing components in fusion devices, and the understanding of the mechanism of physical phenomena initiating modifications of mechanical properties of W-based thin films on carbon based substrates under high-flux, low-energy H+ ions irradiation in the range of temperatures up to 1000°C.

Descriptions of work:

• Fabrication of W coatings by magnetron sputter deposition;
• Structural and compositional investigation of W coatings;
• Plasma/ion beam H exposure of W coatings;
• Studies of W coatings properties after hydrogen ion irradiation;
• Modeling of the surface restructuring and re-deposition effects in W film under high-flux, high-fluence, low-energy hydrogen ion irradiation.

Expected results:

• To form dense nanocrystallline thin W films (optimization of film deposition parameters for thickness and homogenity of W films);
• To investigate structure and composition of W coatings;
• To commit irradiation experiments;
• To model surface redoposition and reconstruction effects on composition and structure of W films initiated H irradiation.

Coordinator: Lithuanian Energy Institute (LEI)

Partners:

• Lithuanian Energy Institute (LEI)
• Vytautas Magnus University (VMU)