Measurement of peeling mode edge current profile dynamics

Peeling modes, an instability mechanism underlying deleterious edge localized mode (ELM) activity in fusion-grade plasmas, are observed at the edge of limited plasmas in a low aspect ratio tokamak under conditions of high edge current density (J(edge) ∼ 0.1  MA/m2) and low magnetic field (B ∼ 0.1  T...

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Published inPhysical review letters Vol. 107; no. 3; p. 035003
Main Authors Bongard, M W, Fonck, R J, Hegna, C C, Redd, A J, Schlossberg, D J
Format Journal Article
LanguageEnglish
Published United States 12.07.2011
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Summary:Peeling modes, an instability mechanism underlying deleterious edge localized mode (ELM) activity in fusion-grade plasmas, are observed at the edge of limited plasmas in a low aspect ratio tokamak under conditions of high edge current density (J(edge) ∼ 0.1  MA/m2) and low magnetic field (B ∼ 0.1  T). They generate edge-localized, electromagnetic activity with low toroidal mode numbers n≤3 and amplitudes that scale strongly with measured J(edge)/B instability drive, consistent with theory. ELM-like field-aligned, current-carrying filaments form from an initial current-hole J(edge) perturbation that detach and propagate outward.
ISSN:1079-7114
DOI:10.1103/PhysRevLett.107.035003