Tungsten behaviour in radiatively cooled plasma discharges in ASDEX Upgrade

TitleTungsten behaviour in radiatively cooled plasma discharges in ASDEX Upgrade
Publication TypeJournal Article
Year of Publication2011
AuthorsR. Neu, A. Kallenbach, M. Sertoli, R. Dux, R. Fischer, J.C Fuchs, A. Janzer, H.W Muller, S. Potzel, T. Putterich, G.J van Rooij
JournalJournal of Nuclear Materials
Volume415
Issue1, Suppl.
Number1
PaginationS322-S326
Date PublishedAug
Type of ArticleArticle; Proceedings Paper
ISBN Number0022-3115
KeywordsDIVERTOR TOKAMAK
Abstract

In the all W ASDEX Upgrade impurities are injected routinely for radiative cooling. Amongst the different species used, nitrogen has been shown to provide the best cooling effect, while maintaining or even improving the energy confinement. Depending on the divertor plasma parameters a reduction or increase of the W sputtering yield compared to the unseeded phases is observed. Although usually the energy confinement is improved during N-2 seeding, no increased W concentrations are observed. Obviously the particle confinement is not improved and there are no signs of central density peaking. Moreover the sustained regular ELM activity prevents a strong inward transport of W across the pedestal region. In contrast, when using Ar as seeding impurity the ELM frequency is strongly reduced and also a change of central particle transport is observed provoking peaking of the W density profile. (C) 2010 Elsevier B.V. All rights reserved.

DOI10.1016/j.jnucmat.2010.09.036
Division

PSI

Department

PSI-E

PID

fe323de9fe351f646db15a93fdbb1314

Alternate TitleJ. Nucl. Mater.

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