Current understanding of the processes underlying the triggering of and energy loss associated with type I ELMs

Abstract

The type I ELMy H-mode is the baseline operating scenario for ITER. While it is known that the type I ELM ultimately results from the peeling-ballooning instability, there is growing experimental evidence that a mode grows up before the ELM crash that may modify the edge plasma, which then leads to the ELM event due to the peeling-ballooning mode. The triggered mode results in the release of a large number of particles and energy from the core plasma but the precise mechanism by which these losses occur is still not fully understood and hence makes predictions for future devices uncertain. Our current understanding of the processes that trigger type I ELMs and the size of the resultant energy loss are reviewed and compared to experimental data and ideas for further development are discussed.

arXiv comment35 pages, 9 figures

References in corpus (10)

• BOUT++: a framework for parallel plasma fluid simulations
• Kinetic instabilities that limit β in the edge of a tokamak plasma: a picture of an H-mode pedestal
• Observation of lobes near the X-point in resonant magnetic perturbation experiments on MAST
• Understanding ELM mitigation by resonant magnetic perturbations on MAST
• Towards the construction of a model to describe the inter-ELM evolution of the pedestal on MAST
• Microtearing modes at the top of the pedestal
• Nonlinear excitation of low-n harmonics in reduced magnetohydrodynamic simulations of edge-localized modes
• MHD and Gyro-kinetic Stability of JET Pedestals
• Resonant magnetic perturbations and divertor footprints in poloidally diverted tokamaks
• Solitary magnetic perturbations at the ELM onset

Cited by in corpus (4)

• Effect of resonant magnetic perturbations on low collisionality discharges in MAST and a comparison with ASDEX Upgrade
• Non-linear extended MHD simulations of type-I edge localised mode cycles in ASDEX Upgrade and their underlying triggering mechanism
• A mechanism for magnetic field stochastization and energy release during an edge pedestal collapse
• Nuclear Fusion: Bringing a star down to Earth