Theory of neoclassical resistivity-gradient-driven turbulence

Technical Report · Thu Dec 01 04:00:00 EST 1988

OSTI ID:6636604

Kwon, O J; Diamond, P H; Hahm, T S

It is shown that rippling instabilities can tap the density gradient expansion free energy source through the density dependence of the neoclassical resistivity. Linear analyses show that the region where neoclassical rippling modes are significantly excited extends from the edge of the plasma to the region where ..nu../sub *e/ less than or equal to 1. Since these modes are non-dispersive, diamagnetic effects are negligible in comparison to the nonlinear decorrelation rate at saturation. Thus, the relevant regime is the 'strong turbulence' regime. The turbulent radial diffusivities of the temperature and the density are obtained as eigenvalues of the renormalized eigenmode equations at steady state. The density gradient acts to enhance the level of turbulence, compared to that driven by the temperature gradient alone. The saturated turbulent state is characterized by: current decoupling, the breakdown of Boltzmann relation, a radial mode scale of density fluctuations exceeding that of temperature fluctuations, implying that density diffusivity exceeds temperature diffusivity, and that density fluctuation levels exceed temperature fluctuation levels. Magnetic fluctuation levels are negligible. 29 refs., 1 fig.

• Research Organization: Texas Univ., Austin (USA). Inst. for Fusion Studies; California Univ., San Diego, La Jolla (USA). Dept. of Physics
• DOE Contract Number: FG05-80ET53088; FG03-88ER53275
• OSTI ID: 6636604
• Report Number(s): DOE/ET/53088-356; IFSR-356; ON: DE89005391
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700103 -- Fusion Energy-- Plasma Research-- Kinetics
700107* -- Fusion Energy-- Plasma Research-- Instabilities
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
ELECTRON TEMPERATURE
INSTABILITY
NEOCLASSICAL TRANSPORT THEORY
NONLINEAR PROBLEMS
PHYSICAL PROPERTIES
PLASMA INSTABILITY
TEMPERATURE GRADIENTS
THERMAL DIFFUSIVITY
THERMODYNAMIC PROPERTIES
THERMONUCLEAR REACTORS
TOKAMAK TYPE REACTORS
TRANSPORT THEORY
TURBULENCE