ELM-free stationary H-mode plasmas in the ASDEX Upgrade tokamak
ELM-free H-mode plasmas with stationary plasma density and radiation level are obtained in the ASDEX Upgrade tokamak with large clearance between the last closed flux surface and the wall, and neutral beam injection in a toroidal direction opposite to that of the plasma current. This behaviour is accompanied by a characteristic narrow-band magnetohydrodynamic (MHD) oscillation with clear harmonics up to n = 11 visible. This mode is localized in the plasma edge region. Conditions and properties of the stationary ELM-free phases and the edge MHD oscillation closely resemble that of the `quiescent H-mode' and the `edge harmonic oscillation' found in the DIII-D tokamak (Burrell K H et al 2002 Plasma Phys. Control. Fusion 44 A253). In addition, high-frequency MHD oscillations are found with amplitude correlated with fluctuations of the diverter D alpha intensity, suggesting a possible relevance of these modes for particle transport.
Bibliographic Reference: An article published in: Plasma Physics and Controlled Fusion 45 (August 2003) 1399-1416
Availability: This article can be accessed online by subscribers, and can be ordered online by non-subscribers, at: http://stacks.iop.org/0741-3335/45/1399
Record Number: 200316742 / Last updated on: 2003-09-15
Original language: en
Available languages: en