Non-linear extended MHD simulations of type-I edge localised mode cycles in ASDEX Upgrade and their underlying triggering mechanism

A. Cathey (Corresponding author), M. Hoelzl, K. Lackner, G. T.A. Huijsmans, M. G. Dunne, E. Wolfrum, S. J.P. Pamela, F. Orain, S. Günter

Research output: Contribution to journalArticleAcademicpeer-review

1 Citation (Scopus)

Abstract

A triggering mechanism responsible for the explosive onset of edge localised modes (ELMs) in fusion plasmas is identified by performing, for the first time, non-linear magnetohydrodynamic simulations of repetitive type-I ELMs. Briefly prior to the ELM crash, destabilising and stabilising terms are affected at different timescales by an increasingly ergodic magnetic field caused by non-linear interactions between the axisymmetric background plasma and growing non-axisymmetric perturbations. The separation of timescales prompts the explosive, i.e. faster than exponential, growth of an ELM crash which lasts ∼ 500μs. The duration and size of the simulated ELM crashes compare qualitatively well with type-I ELMs in ASDEX Upgrade. As expected for type-I ELMs, a direct proportionality between the heating power in the simulations and the ELM repetition frequency is obtained. The simulations presented here are a major step forward towards predictive modelling of ELMs and of the assessment of mitigation techniques in ITER and other future tokamaks.

Original languageEnglish
Article number124007
Number of pages7
JournalNuclear Fusion
Volume60
Issue number12
DOIs
Publication statusPublished - Dec 2020

Keywords

  • ELM simulations
  • extended MHD
  • JOREK
  • magnetic reconnection
  • non-linear MHD

Fingerprint Dive into the research topics of 'Non-linear extended MHD simulations of type-I edge localised mode cycles in ASDEX Upgrade and their underlying triggering mechanism'. Together they form a unique fingerprint.

Cite this