### Direct observation of current in type I ELM filaments on Asdex UpgradeDirect observation of current in type I ELM filaments on Asdex Upgrade

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 Author Vianello, N. ♦ Naulin, V. ♦ Schrittwieser, R. ♦ Muller, H. W. ♦ Zuin, M. ♦ Ionita, C. ♦ Rasmussen, J. J. ♦ Mehlmann, F. ♦ Rohde, V. ♦ Cavazzana, R. ♦ Maraschek, M. Source arXiv.org Content type Text File Format PDF Date of Submission 2009-10-13 Language English
 Subject Domain (in DDC) Computer science, information & general works ♦ Natural sciences & mathematics ♦ Physics Subject Keyword Physics - Plasma Physics ♦ physics:physics Abstract Magnetically confined plasmas are often subject to relaxation oscillations accompanied by large transport events. This is particularly the case for the high confinement regime of tokamaks where these events are termed edge localized modes (ELMs). They result in the temporary breakdown of the high confinement and lead to high power loads on plasma facing components. Present theories of ELM generation rely on a combined effect of edge currents and the edge pressure gradient exceeding critical values which result in intermediate mode number ($n \cong 10-15$) structures (\emph{filaments}) localized in the perpendicular plane and extended along the field line. It is shown here by detailed localized measurements of the three components of the magnetic field perturbation carried by an individual type I ELM filament that these filaments carry a substantial current. The observations provide essential information for the understanding of ELM dynamics. Educational Use Research Learning Resource Type Article