Toroidally asymmetric ELM precursors in TCV
Various types of edge localized modes (ELMs) have been obtained in TCV ohmic H-modes. Clearly identified type III ELMs and large ELMs show coherent magnetic precursor oscillations. The strong localization of these precursors on the bad curvature side of the plasma and their medium toroidal mode numbers indicate their ballooning character. These modes start toroidally localized and grow in amplitude and toroidal extent. When the precursor encompasses the whole toroidal circumference, the increased transport phase, as indicated by the characteristic D(alpha) spike, begins. It is found that the asymmetry causing a localized onset must be intrinsic to the plasma.
Bibliographic Reference: Article: Nuclear Fusion (1997)
Record Number: 199711464 / Last updated on: 1997-11-18
Original language: en
Available languages: en