Coherent nonlinear coupling between a long-wavelength mode and small-scale turbulence in the TEXT tokamak

Journal Article · Mon Apr 26 00:00:00 EDT 1993 · Physical Review Letters; (United States)

DOI:https://doi.org/10.1103/PhysRevLett.70.2565· OSTI ID:6768466

Tsui, H Y.W.; Rypdal, K; Ritz, C P; Wootton, A J ^[1]

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1. Fusion Research Center, The University of Texas at Austin, Austin, Texas 78712 (United States)

Bispectral analysis of Langmuir probe data indicates that coherent nonlinear coupling, in addition to the noncoherent turbulent interactions, exists in the edge plasma of the tokamak TEXT. Not all the modes involved reside within the spectral region of the usual broadband turbulence. At a major resonant surface the small-scale turbulent activity interacts [ital coherently] with a localized long-wavelength mode; a signature of regular or coherent structure. By the observed coupling to the transport related turbulence, the long-wavelength mode can influence plasma confinement indirectly. These observations signify the influence of low-order resonant surfaces on the edge turbulence in tokamaks.

• DOE Contract Number: FG05-88ER53267
• OSTI ID: 6768466
• Journal Information: Physical Review Letters; (United States), Vol. 70:17; ISSN 0031-9007
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
PLASMA
NONLINEAR PROBLEMS
TEXT DEVICES
TURBULENCE
COHERENT RADIATION
COUPLING
END EFFECTS
EXPERIMENTAL DATA
FLUCTUATIONS
LANGMUIR PROBE
OSCILLATION MODES
RESONANCE
CLOSED PLASMA DEVICES
DATA
ELECTRIC PROBES
ELECTROMAGNETIC RADIATION
INFORMATION
NUMERICAL DATA
PROBES
RADIATIONS
THERMONUCLEAR DEVICES
TOKAMAK DEVICES
VARIATIONS
700330* - Plasma Kinetics
Transport
& Impurities- (1992-)
700340 - Plasma Waves
Oscillations
& Instabilities- (1992-)
700320 - Plasma Diagnostic Techniques & Instrumentation- (1992-)