Observation of Spontaneous Neoclassical Tearing Modes

Technical Report · Wed Oct 03 04:00:00 EDT 2001

DOI:https://doi.org/10.2172/788446· OSTI ID:788446

Fredrickson, E D ^[1]

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1. Princeton Plasma Physics Laboratory

We present data in this paper from the Tokamak Fusion Test Reactor (TFTR) which challenges the commonly held belief that extrinsic MHD events such as sawteeth or ELMs [edge localized modes] are required to provide the seed islands that trigger Neoclassical Tearing Modes (NTMs). While sawteeth are reported to provide the trigger for most of the NTMs on DIII-D [at General Atomics in San Diego, California] and ASDEX-U [at Max-Planck-Institut fuer Plasmaphysik in Garching, Germany], the majority of NTMs seen in TFTR occur in plasmas without sawteeth, that is which are above the beta threshold for sawtooth stabilization. Examples of NTMs appearing in the absence of any detectable extrinsic MHD activity will be shown. Conversely, large n=1 modes in plasmas above the NTM beta threshold generally do not trigger NTMs. An alternative mechanism for generating seed islands will be discussed.

• Research Organization: Princeton Plasma Physics Lab., NJ (US)
• Sponsoring Organization: USDOE Office of Science (US)
• DOE Contract Number: AC02-76CH03073
• OSTI ID: 788446
• Report Number(s): PPPL-3616
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
ASDEX TOKAMAK
DOUBLET-3 DEVICE
EDGE LOCALIZED MODES
MAGNETOHYDRODYNAMICS
SAWTOOTH OSCILLATIONS
TEARING INSTABILITY
TFTR TOKAMAK