Plasma-wall interaction studies related to fusion reactor materials

• Unité de recherche: OFEN
• Numéro de projet: 101836

Mots-clé (Allemand)

TP0084;F-Kernenergie

Description succincte (Allemand)

Amongst the various problems still to be solved before being able to use fusion reaction as a reliable energy source, the plasma-wall interactions and their consequences for the lifetime of the plasma facing components is of highest importance. One of these particular components, named first mirror, is one of most critical elements of ITER¿s diagnostic systems. Indeed it should maintain the required optical performance despite the very harsh conditions in a fusion reactor.It is the aim of the present project to solve various problems related to the use of metallic mirrors as plasma viewing component in ITER through extensive collaborations with groups from different Tokamaks. Special interest will be drawn to the assessment of the lifetime of potential mirror materials by dedicated experiments in today¿s Tokamaks and to study the feasibility of in-situ cleaning techniques for mirrors. Investigation of the possible realization of high quality rhodium-coated mirrors will also be provided. Apart from experimen ts carried-out in various Tokamaks research will be performed in addition in laboratory experiments at the Institute of Physics in Basel in the form of general surface analysis, optical characterization and experimental simulation of erosion and deposition processes.

Rapport final (Anglais)

In the course of the ongoing project, our research was focused on the realisation of rhodium and molybdenum coated mirrors. The growing interest about the use of rhodium (Rh) as a material for the first mirrors in ITER (International Thermonuclear Experimental Reactor) and the necessity of using it as a thin film deposited on a polished substrate has raised the necessity of the development of a robust deposition technique for the preparation of highreflectivity mirrors. A robust method, magnetron sputtering for depositing high quality films was successfully tested at the University of Basel. Amongst all investigated parameters (deposition rate, substrate temperature, metal substrate…), only the gas pressure during deposition was observed to have an influence on the optical properties of the film. Otherwise, the measured reflectivity is close to the reflectivity calculated from optical constants of pure rhodium. Storage of samples in air did not affect the reflectivity in contrast to molybdenum deposited mirrors.

Auftragnehmer/Contractant/Contraente/Contractor:
Departement Physik der Universität Basel

Autorschaft/Auteurs/Autori/Authors:
Oelhafen,P.

Documents annexés

• Studies related to plasma-wall interactions in ITER - Final Scientific Report 2009 [PDF] 4'399 kB