Title: Plasmoid-mediated reconnection during nonlinear peeling–ballooning edge-localized modes

Journal Article · · Nuclear Fusion

Abstract Plasmoid-mediated reconnection is investigated for nonlinear peeling–ballooning edge-localized modes (P-B ELMs). The formation of current sheets and the transition to 3D current sheet instability is demonstrated through fully nonlinear resistive MHD simulations of P-B ELMs in DIII-D discharges. Large-scale axisymmetric current sheets, as well as small-scale poloidally extended current sheets, are formed as the coherent P-B ELM filaments nonlinearly evolve. It is observed that, at high Lundquist numbers, these current sheets break during a reconnection burst, i.e. a secondary exponential growth of intermediate modes followed by relaxation due to the suppression of P-B drive.

Research Organization:
Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States). National Energy Research Scientific Computing Center (NERSC); Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ (United States)
Sponsoring Organization:
USDOE; USDOE Office of Science (SC), Fusion Energy Sciences (FES)
Grant/Contract Number:
AC02-09CH11466; SC0010565; SC0012467
OSTI ID:
2203575
Journal Information:
Nuclear Fusion, Journal Name: Nuclear Fusion Journal Issue: 12 Vol. 63; ISSN 0029-5515
Publisher:
IOP PublishingCopyright Statement
Country of Publication:
IAEA
Language:
English

References (54)

Nonlinear magnetohydrodynamics simulation using high-order finite elements journal March 2004
Edge stability and transport control with resonant magnetic perturbations in collisionless tokamak plasmas journal May 2006
Edge localized modes and the pedestal: A model based on coupled peeling–ballooning modes journal May 2002
Numerical studies of edge localized instabilities in tokamaks journal April 2002
Instability of current sheets and formation of plasmoid chains journal October 2007
Fast reconnection in high-Lundquist-number plasmas due to the plasmoid Instability journal November 2009
Edge localized linear ideal magnetohydrodynamic instability studies in an extended-magnetohydrodynamic code journal March 2010
Scaling laws of resistive magnetohydrodynamic reconnection in the high-Lundquist-number, plasmoid-unstable regime journal June 2010
Ideal and resistive edge stability calculations with M3D-C1 journal October 2010
Stabilizing effects of edge current density on pedestal instabilities journal March 2012
Magnetic reconnection and stochastic plasmoid chains in high-Lundquist-number plasmas journal April 2012
Plasmoid instability in high-Lundquist-number magnetic reconnection journal May 2013
Nonlinear excitation of low-n harmonics in reduced magnetohydrodynamic simulations of edge-localized modes journal August 2013
Edge-localized-modes in tokamaks journal September 2014
Correlations between quasi-coherent fluctuations and the pedestal evolution during the inter-edge localized modes phase on DIII-Da) journal May 2015
Visco-resistive plasmoid instability journal March 2016
Microturbulence in DIII-D tokamak pedestal. III. Effects of collisions journal December 2016
Dynamo-driven plasmoid formation from a current-sheet instability journal December 2016
Nonlinear reconnecting edge localized modes in current-carrying plasmas journal May 2017
Magnetic flux pumping in 3D nonlinear magnetohydrodynamic simulations journal October 2017
Nonlinear saturation of kinetic ballooning modes by zonal fields in toroidal plasmas journal January 2019
Magnetic reconnection via current sheets journal January 1986
Neoclassical conductivity and bootstrap current formulas for general axisymmetric equilibria and arbitrary collisionality regime journal July 1999
Extended full-MHD simulation of non-linear instabilities in tokamak plasmas journal October 2020
Novel 2D velocity estimation method for large transient events in plasmas journal August 2021
Local measurements of the pedestal magnetic field profile throughout the ELM cycle on DIII-D journal October 2022
Tokamak-like confinement at a high beta and low toroidal field in the MST reversed field pinch journal December 2003
MHD stability in X-point geometry: simulation of ELMs journal June 2007
Pedestal stability comparison and ITER pedestal prediction journal July 2009
ELM destabilization by externally applied non-axisymmetric magnetic perturbations in NSTX journal February 2010
Broadening of divertor heat flux profile with increasing number of ELM filaments in NSTX journal November 2014
Large-volume flux closure during plasmoid-mediated reconnection in coaxial helicity injection journal March 2016
Edge-localized modes - physics and theory journal May 1998
Magneto-hydrodynamic stability of the H-mode transport barrier as a model for edge localized modes: an overview journal April 2006
Modelling of ELM dynamics for DIII-D and ITER journal June 2007
Fast sawtooth reconnection at realistic Lundquist numbers journal November 2014
Nonlinear coupling induced toroidal structure of edge localized modes journal December 2017
Towards validated MHD modeling of edge harmonic oscillation in DIII-D QH-mode discharges journal July 2020
Intense whistler-frequency emissions at the pedestal collapse in KSTAR H-mode plasmas journal October 2020
Non-linear extended MHD simulations of type-I edge localised mode cycles in ASDEX Upgrade and their underlying triggering mechanism journal November 2020
The JOREK non-linear extended MHD code and applications to large-scale instabilities and their control in magnetically confined fusion plasmas journal April 2021
Computing nonlinear magnetohydrodynamic edge localized instabilities in fusion plasmas journal September 2006
Two-fluid studies of edge relaxation events in tokamaks journal July 2007
Absence of Complete Finite-Larmor-Radius Stabilization in Extended MHD journal August 2008
Edge-Localized-Mode Suppression through Density-Profile Modification with Lithium-Wall Coatings in the National Spherical Torus Experiment journal August 2009
Observation of Edge Instability Limiting the Pedestal Growth in Tokamak Plasmas journal March 2014
Helicity-Flux-Driven α Effect in Laboratory and Astrophysical Plasmas journal March 2014
Resistive Reduced MHD Modeling of Multi-Edge-Localized-Mode Cycles in Tokamak X -Point Plasmas journal January 2015
Plasmoids Formation During Simulations of Coaxial Helicity Injection in the National Spherical Torus Experiment journal May 2015
Nonlinear Interaction of Edge-Localized Modes and Turbulent Eddies in Toroidal Plasma under n = 1 Magnetic Perturbation journal August 2016
Cause of Sudden Magnetic Reconnection in a Laboratory Plasma journal April 2006
Evolution of Filament Structures during Edge-Localized Modes in the MAST Tokamak journal May 2006
Momentum Transport from Current-Driven Reconnection in the Reversed Field Pinch journal August 2007
Plasmoid-induced-reconnection and fractal reconnection journal June 2001