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

Journal Article · Sat Jun 01 00:00:00 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), Vol. 3:6; ISSN 0899-8221
• Country of Publication: United States
• Language: English

Related Subjects

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