Diffusion of plasma and magnetic field in a tokamak due to anomalous electron viscosity

Journal Article · Mon Sep 01 04:00:00 EDT 1980 · Sov. J. Plasma Phys. (Engl. Transl.); (United States)

OSTI ID:6279788

Pereverzev, G V; Yushmanov, P N

The enhanced transport in tokamaks is explained by a process which reduces to anomalous e-e collisions. In the simple case delT = 0 the only macroscopic characteristics of the anomalous electron collisions is the viscous force, which, as in the case of Coulomb collisions, has only a poloidal component by virtue of the axial symmetry of the system. The appearance of an additional viscous force increases the plasma diffusion velocity and distorts the poloidal projection of Ohm's law. At a high diffusion velocity, corresponding to that observed experimentally, the poloidal field H/sub theta/ is frozen in the plasma, not in the strong toroidal field of the tokamak, H/sub phi/. The plasma entrains the poloidal field and thus the current in its radial motion, which enables one to explain the experimentally, observed rapid current rise and simultaneous gas injection, in which there is no skin effect in the current density, in contradiction of the neoclassical theory. Furthermore, the distuption of the mutual freezing-in of the fields H/sub theta/ and H/sub phi/ may destroy the magnetic configuration over the diffusion time, rather than the skin time. Even if there is no anomalous behavior, this effect is important for tokamaks with conserved fluxes and for tokamak reactors, in which the plasma pressure may be high, ..beta../sub theta/>epsilon/sup -1/2/. The explanation for the elevated plasma diffusion in terms of an anomalous electron viscosity leads to a proportional increase in the particle pinch velocity v/sub p/, in addition to the increase in the diffusion coefficient D. The ranges of D and v/sub p/ can be specified without making any assumptions about the mechanism for the anomalous behavior. These ranges are D/sup n/c< or =D

• Research Organization: I. V. Kurchatov Institute of Atomic Energy, Moscow
• OSTI ID: 6279788
• Journal Information: Sov. J. Plasma Phys. (Engl. Transl.); (United States), Journal Name: Sov. J. Plasma Phys. (Engl. Transl.); (United States) Vol. 6:5; ISSN SJPPD
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700101* -- Fusion Energy-- Plasma Research-- Confinement
Heating
&amp; Production
ANNULAR SPACE
BANANA REGIME
CLOSED PLASMA DEVICES
COLLISIONS
CONFIGURATION
CONFINEMENT TIME
DIFFUSION
ELECTRON COLLISIONS
ELECTRON-ELECTRON COLLISIONS
PHYSICAL PROPERTIES
PINCH EFFECT
SKIN EFFECT
SPACE
THERMAL CONDUCTIVITY
THERMODYNAMIC PROPERTIES
THERMONUCLEAR DEVICES
TOKAMAK DEVICES
TOROIDAL CONFIGURATION
TRANSPORT THEORY
TRAPPING
VISCOSITY