Characteristics of type I and type III ELM precursors in ASDEX upgrade
- 1 January 1998
- journal article
- Published by IOP Publishing in Nuclear Fusion
- Vol. 38 (1) , 111-116
- https://doi.org/10.1088/0029-5515/38/1/310
Abstract
The temporal evolution of the edge electron pressure gradient during the development of a type I ELM shows that proximity of ∇pedge to the ideal ballooning limit is not sufficient to trigger a type I ELM. Thus, the MHD structure of ELMs is investigated further. The present discussion focuses on the phenomenology of type I and type III ELM precursors. The ELM precursor types are well distinguished by their frequency behaviour and mode structure. The type I ELM precursor oscillation originates from a thin layer close to the plasma edge. For type III ELMs, on the contrary, ∇pedge has a much stronger influence as indicated by their occurrence during L mode.Keywords
This publication has 6 references indexed in Scilit:
- Characteristics of edge localized modes in ASDEX UpgradePlasma Physics and Controlled Fusion, 1996
- ELM studies on the COMPASS-D tokamakPlasma Physics and Controlled Fusion, 1996
- Edge localized modes (ELMs)Plasma Physics and Controlled Fusion, 1996
- Stabilization of external modes in tokamaks by resistive walls and plasma rotationPhysical Review Letters, 1994
- Modifications in turbulence and edge electric fields at the L–H transition in the DIII-D tokamakPhysics of Fluids B: Plasma Physics, 1991
- MHD mode structure and propagation in the ASDEX tokamakNuclear Fusion, 1991