Particle transport theory with ICRH and ECRH in tokamaks

Thesis/Dissertation · Fri Jan 01 04:00:00 EST 1993

OSTI ID:6855759

Indireshkumar, K

Previous theoretical studies have shown that a poloidal potential variation of order [epsilon] (=r/R), which is likely to be produced during high power electron and ion cyclotron wave heating (ECRH and ICRH), can significantly enhance neoclassical transport in a simple plasma model consisting of one ion species and electrons in the low collisionality regime. The more realistic case of a plasma model with one or more impurity ion species present, in which the effects of a poloidal potential variation are likely to be more significant, has not been investigated previously. In this thesis, the effects of a poloidal electric field of order [epsilon] upon particle transport and current in a tokamak plasma with a significant impurity content are studied theoretically. A kinetic theory approach is used to obtained the neoclassical transport coefficients for a large aspect ratio ([epsilon][much lt]1) tokamak in the low collisionality regime. Calculations indicate that, in an impure plasma, a poloidal electric field can significantly enhance (by a factor of [approximately]3) ion diffusion, while its effect on the electron transport is similar to that obtained in the previous studies for a simple plasma. The magnitude of the ion transport enhancement is found to depend upon the impurity content, impurity species, and the magnitude of the poloidal electric field. Enhancement of the neoclassical conductivity is found to be similar to that obtained in the previous studies; however, in the presence of a large impurity concentration, results of the present work can sometimes differ from those in the previous studies by [approximately]20%. A poloidal electric field causes a significant enhancement (a factor of [approximately]2) of the bootstrap current coefficients. The nature of density and temperature profiles seem to be important in determining the change in the bootstrap current.

• Research Organization: Georgia Inst. of Tech., Atlanta, GA (United States)
• OSTI ID: 6855759
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700330* -- Plasma Kinetics
Transport
& Impurities-- (1992-)
BOOTSTRAP CURRENT
CLOSED PLASMA DEVICES
CURRENTS
ECR HEATING
ELECTRIC CURRENTS
HEATING
HIGH-FREQUENCY HEATING
ICR HEATING
NEOCLASSICAL TRANSPORT THEORY
PLASMA HEATING
THERMONUCLEAR DEVICES
TOKAMAK DEVICES
TRANSPORT THEORY