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arXiv · 0910.5873

Observation of confined current ribbon in JET plasmas

E. R. Solano·P. J. Lomas·B. Alper·G. S. Xu·Y. Andrew·G. Arnoux·A. Boboc·L. Barrera·P. Belo·M. N. A. Beurskens·M. Brix·K. Crombe·E. de la Luna·S. Devaux·T. Eich·S. Gerasimov·C. Giroud·D. Harting·D. Howell·A. Huber·G. Kocsis·A. Korotkov·A. Lopez-Fraguas·M. F. F. Nave·E. Rachlew·F. Rimini·S. Saarelma·A. Sirinelli·H. Thomsen·L. Zabeo·D. Zarzoso·JET EFDA contributors
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Abstract

we report the identification of a localised current structure inside the JET plasma. It is a field aligned closed helical ribbon, carrying current in the same direction as the background current profile (co-current), rotating toroidally with the ion velocity (co-rotating). It appears to be located at a flat spot in the plasma pressure profile, at the top of the pedestal. The structure appears spontaneously in low density, high rotation plasmas, and can last up to 1.4 s, a time comparable to a local resistive time. It considerably delays the appearance of the first ELM.

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E. R. Solano, P. J. Lomas, B. Alper, G. S. Xu, Y. Andrew, G. Arnoux, A. Boboc, L. Barrera, P. Belo, M. N. A. Beurskens, M. Brix, K. Crombe, E. de la Luna, S. Devaux, T. Eich, S. Gerasimov, C. Giroud, D. Harting, D. Howell, A. Huber, G. Kocsis, A. Korotkov, A. Lopez-Fraguas, M. F. F. Nave, E. Rachlew, F. Rimini, S. Saarelma, A. Sirinelli, H. Thomsen, L. Zabeo, D. Zarzoso, JET EFDA contributors. 2009-10-30. Observation of confined current ribbon in JET plasmas. https://doi.org/10.1103/physrevlett.104.185003

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