title: Measurement of peeling mode edge current profile dynamics.
abstract: 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.
authors.affiliation: Department of Engineering Physics, University of Wisconsin-Madison, 1500 Engineering Drive, Madison, Wisconsin 53706, USA.
authors.forename: M W
authors.initials: MW
authors.lastname: Bongard
authors.forename: R J
authors.initials: RJ
authors.lastname: Fonck
authors.forename: C C
authors.initials: CC
authors.lastname: Hegna
authors.forename: A J
authors.initials: AJ
authors.lastname: Redd
authors.forename: D J
authors.initials: DJ
authors.lastname: Schlossberg