Hannover 2010 – scientific programme
Parts | Days | Selection | Search | Downloads | Help
P: Fachverband Plasmaphysik
P 16: Plasma-Wall Interaction
P 16.3: Talk
Thursday, March 11, 2010, 14:55–15:10, B 302
Influence of erosion on optical properties of diagnostic mirrors for ITER depending on their material and manufacturing technique — •Maria Matveeva1, Andrey Litnovsky1, Laurent Marot2, Baran Eren2, Volker Philipps1, and Ulrich Samm1 — 1Institut für Energieforschung - Plasmaphysik, Forschungszentrum Jülich GmbH, Association EURATOM-FZJ, Trilateral Euregio Cluster, Jülich, Germany — 2Department of Physics, University of Basel, Basel, Switzerland
Metallic mirrors will be used as plasma-viewing elements for all optical diagnostics of ITER. Erosion can drastically increase the roughness of mirrors deteriorating their reflectivity. To investigate the different candidate materials for ITER mirrors under erosion conditions, experiments were carried out in TEXTOR tokamak. Single crystal molybdenum mirrors, rhodium- and molybdenum-coated mirrors on different substrates were exposed in edge plasmas. In previous experiments all mirrors demonstrated acceptable performance under erosion conditions at elevated temperature of 350∘C-570∘C: overall changes in reflectivity did not exceed 4% in the wavelength range 250-2500 nm. However, observed defects of molybdenum and rhodium coatings called for improvement of the coating technique. In the new experiment another concept of rhodium coating on tungsten was tested allowing the exposure at the temperatures about 800∘C. Detailed results of the experiments will be presented in this contribution as well as an assessment of applicability of studied mirror concepts in ITER diagnostics.