Suppression of large edge-localized modes in high-confinement DIII-D plasmas with a stochastic magnetic boundary

Evans, T; Moyer, R; Thomas, P. R; Watkins, J. G; Osborne, T. H; Boedo, J; Doyle, Edward Dermot; Fenstermacher, M. E; Flux, I. A; Groebner, R. J; Groth, M; Harris, Jeffrey; La Haye, R. J; Lasnier, C. J; Masuzaki, S; Ohyabu, N; Pretty, David; Rhodes, T. L; Reimerdes, H; Rudakov, D; Schaffer, M. J; Wang, G; Zeng, Z

Suppression of large edge-localized modes in high-confinement DIII-D plasmas with a stochastic magnetic boundary

Date

2004

Authors

Evans, T

Moyer, R

Thomas, P. R

Watkins, J. G

Osborne, T. H

Boedo, J

Doyle, Edward Dermot

Fenstermacher, M. E

Flux, I. A

Groebner, R. J

Publisher

American Physical Society

Abstract

The large edge-localized modes (ELM) in high confinement (H-mode) plasmas were suppressed using a magnetic boundary, produced by an applied edge resonant magnetic perturbation. The magnetic perturbations were produced by a set of control coils, referred to as I coil, located inside the vacuum vessel. The plasmas used in the experiment were double null diverted discharges with a 2 cm downward shift. The results demonstrate that stochastic boundary layers are compatible with H-mode plasmas and that a stochastic layer can suppress ELMs without degrading the global particle and energy confinement.