Stuttgart 2012 – scientific programme

Parts | Days | Selection | Search | Updates | Downloads | Help

P: Fachverband Plasmaphysik

P 26: Plasma-Wand-Wechselwirkung

P 26.3: Talk

Friday, March 16, 2012, 15:00–15:15, V57.02

Analysis of erosion and material migration in a 3D plasma boundary at TEXTOR — •R. Laengner, O. Schmitz, A. Kirschner, A. Kreter, S. Brezinsek, M. Laengner, J.W. Coenen, S. Möller, P. Wienhold, and U. Samm — Institute of Energy and Climate Research - Plasma Physics, Forschungszentrum Jülich GmbH, Association EURATOM-FZJ, Partner in the Trilateral Euregio Cluster, Jülich, Germany

For the mitigation of Edge Localized Modes, magnetic perturbation (RMP) coils are planned for ITER. Modeling shows that ITER strike lines break up into three dimensional structures during RMP application. This has been observed and analyzed at the TEXTOR Dynamic Ergodic Divertor (DED) and other tokamaks as well. Experiments at TEXTOR were performed to quantify erosion and material migration processes in the 3D plasma boundary. Carbon test limiters were exposed to both a non perturbed plasma and one with RMP. During the plasma discharges, methane ¹³CH₄was puffed through a hole in the limiter, for enlarging the erosion source, where ¹³C acted as a tracer material. The direction of the light emission formed by the injected particles, observed in CII, CIII and CH light, was tilted clearly against the typical flag in the ExB drift direction of the non-RMP case. This was quantified by Nuclear Reaction Analysis (NRA), via measurements of ¹³C deposition patterns. NRA also showed an increase of fuel retention during RMP. This effect is probably caused by a decrease of the surface temperature by 40%. This shows that the 3D topology impacts the plasma parameters and hence the erosion and migration processes.