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

Phys Rev Lett. 2004 Jun 11;92(23):235003. doi: 10.1103/PhysRevLett.92.235003. Epub 2004 Jun 10.

Abstract

A stochastic magnetic boundary, produced by an applied edge resonant magnetic perturbation, is used to suppress most large edge-localized modes (ELMs) in high confinement (H-mode) plasmas. The resulting H mode displays rapid, small oscillations with a bursty character modulated by a coherent 130 Hz envelope. The H mode transport barrier and core confinement are unaffected by the stochastic boundary, despite a threefold drop in the toroidal rotation. These results demonstrate that stochastic boundaries are compatible with H modes and may be attractive for ELM control in next-step fusion tokamaks.