Nonlinear theory of trapped-electron temperature-gradient-driven turbulence in flat density H-mode plasmas

Journal Article · Sat Jun 01 04:00:00 EDT 1991 · Physics of Fluids B; (USA)

DOI:https://doi.org/10.1063/1.859710· OSTI ID:5534989

Hahm, T S ^[1]

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1. Plasma Physics Laboratory, Princeton University, Princeton, New Jersey 08543 (USA)

Ion-temperature-gradient turbulence-based transport models have difficulties reconciling the recent DIII-D H-mode results ({ital Proceedings} {ital of} 17{ital th} {ital European} {ital Conference} {ital on} {ital Controlled} {ital Fusion} {ital and} {ital Plasma} {ital Heating} (EPS, Geneva, 1990), Vol. 1, p. 271), where the density profile is flat, but {chi}{sub {ital e}}{gt}{chi}{sub {ital i}} in the core region. In this work, a nonlinear theory is developed for recently discovered ion-temperature-gradient trapped-electron modes propagating in the electron diamagnetic direction. This instability is predicted to be linearly unstable for {ital L}{sub {ital T}{sub {ital i}}}/{ital R}{approx lt}{ital k}{sub {theta}}{rho}{sub {ital s}}{approx lt} ({ital L}{sub {ital T}{sub {ital i}}}/{ital R}){sup 1/4}. They are also found to be strongly dispersive even at these long wavelengths, thereby suggesting the importance of the wave--particle--wave interactions in the nonlinear saturation phase. The fluctuation spectrum and anomalous fluxes are calculated. In accordance with the trends observed in DIII-D, the predicted electron thermal diffusivity can be larger than the ion thermal diffusivity.

• DOE Contract Number: AC02-76CH03073
• OSTI ID: 5534989
• Journal Information: Physics of Fluids B; (USA), Journal Name: Physics of Fluids B; (USA) Vol. 3:6; ISSN 0899-8221; ISSN PFBPE
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700107* -- Fusion Energy-- Plasma Research-- Instabilities
ANNULAR SPACE
CLOSED CONFIGURATIONS
CLOSED PLASMA DEVICES
COLLISIONLESS PLASMA
CONFIGURATION
DISPERSION RELATIONS
ELECTRON TEMPERATURE
ELECTRONS
ELEMENTARY PARTICLES
ENERGY SPECTRA
FERMIONS
FLUCTUATIONS
INSTABILITY
ION TEMPERATURE
LEPTONS
MAGNETIC FIELD CONFIGURATIONS
NONLINEAR PROBLEMS
PHYSICAL PROPERTIES
PLASMA
PLASMA DENSITY
PLASMA INSTABILITY
PLASMA MACROINSTABILITIES
PLASMA MICROINSTABILITIES
SPACE
SPECTRA
TEMPERATURE GRADIENTS
THERMAL DIFFUSIVITY
THERMODYNAMIC PROPERTIES
THERMONUCLEAR DEVICES
TOKAMAK DEVICES
TOROIDAL CONFIGURATION
TRAPPED-PARTICLE INSTABILITY
TRAPPING
TURBULENCE
VARIATIONS