Study of surfaces and surface layers on high temperature materials after short time thermal loads

Being part of the plasma-wall interaction during TOKAMAK operation, erosion- and redeposition processes of First Wall materials substantially influence plasma parameters as well as the properties of the First Wall. An important redeposition process of eroded material isthe formation of thin films by atomic condensation. Examinations of First Wall components after TOKAMAK operation lead to the assumptionthat these thin metallic films tend to agglomerate to small particles under subsequent heat load. In laboratory experiments it is shown thatthin metallic films on various substrates can agglomerate under short time high heat fluxes and also under longer lasting lower thermal loads, thus verifying the "agglomeration hypothesis"