Nonlinear reconnecting edge localized modes in tokamaks

Abstract

Nonlinear edge localized modes in a tokamak are examined using global three-dimensional resistive magnetohydrodynamics simulations. Coherent current-carrying filament (ribbon-like) structures wrapped around the torus are nonlinearly formed due to nonaxisymmetric reconnecting current sheet instabilities, the so called peeling-like edge localized modes. These fast growing modes saturate by breaking axisymmetric current layers isolated near the plasma edge and go through repetitive relaxation cycles by expelling current radially outward and relaxing it back. The local bi-directional fluctuation-induced electromotive force (emf) from the edge localized modes, the dynamo action, relaxes the axisymmetric current density and forms current holes near the edge.

5 pages, 5 figures

References in corpus (5)

• Ideal kink instability of a magnetic loop equilibrium
• General Theory of the Plasmoid Instability
• Plasmoids formation during simulations of coaxial helicity injection in the National Spherical Torus Experiment
• Surface appearance of dynamo-generated large-scale fields
• Dynamo-driven plasmoid formation from a current-sheet instability

Cited by in corpus (7)

• The JOREK non-linear extended MHD code and applications to large-scale instabilities and their control in magnetically confined fusion plasmas
• The interplay of magnetically-dominated turbulence and magnetic reconnection in producing nonthermal particles
• Experimental investigation of coaxial-gun-formed plasmas injected into a background transverse magnetic field or plasma
• Plasmoid-mediated reconnection during nonlinear peeling-ballooning edge-localized modes
• An Alfvenic reconnecting plasmoid thruster
• Effects of Plasmoid Formation on Sawtooth Process in a Tokamak
• Filamentary plasma eruptions and the heating and acceleration of electrons