Effects of a poloidal divertor separatrix on resistive magnetohydrodynamic instabilities in a tokamak

Journal Article · Tue Mar 01 04:00:00 EST 1994 · Physics of Plasmas; (United States)

DOI:https://doi.org/10.1063/1.870810· OSTI ID:6922315

Uchimoto, E; Callen, J D; Chang, Z; Prager, S C ^[1]

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1. Department of Physics, University of Wisconsin, Madison, Wisconsin 53706 (United States)

A computer code package has been developed to simulate the linear and nonlinear evolution of long-wavelength resistive magnetohydrodynamic (MHD) instabilities in a four-node poloidal divertor tokamak (e.g., Wisconsin Tokapole II [Nucl. Fusion [bold 19], 1509 (1979)]). Distinguishing features of this package include the use of a full set of three-dimensional (3-D) nonlinear resistive MHD equations and the inclusion of the divertor separatrix and the plasma outside the divertor separatrix in the computational domain. The present numerical results suggest that the plasma current outside the divertor separatrix tends to linearly stabilize the resistive MHD instability dominated by the [ital m]=2, [ital n]=1 mode, and, to a lesser extent, that dominated by the [ital m]=1, [ital n]=1 mode. (Here, [ital m] and [ital n] are poloidal and toroidal mode numbers, respectively.) However, the nonlinear evolution of the [ital m]=1, [ital n]=1 dominant instability is not significantly affected by the divertor configuration; the [ital m]=1, [ital n]=1 island is shown to reconnect totally by developing a large region of magnetic stochasticity. Hence, the cause of the partial reconnection observed in Tokapole II seems to lie beyond the scope of the classical resistive MHD model.

• OSTI ID: 6922315
• Journal Information: Physics of Plasmas; (United States), Journal Name: Physics of Plasmas; (United States) Vol. 1:3; ISSN PHPAEN; ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700370* -- Plasma Fluid & MHD Properties-- (1992-)
CLOSED PLASMA DEVICES
COMPUTER CODES
CONFIGURATION
DIVERTORS
EQUILIBRIUM
FLUID MECHANICS
HELICAL CONFIGURATION
HYDRODYNAMICS
INSTABILITY
MAGNETIC FIELD CONFIGURATIONS
MAGNETIC ISLANDS
MAGNETOHYDRODYNAMICS
MECHANICS
MHD EQUILIBRIUM
NUMERICAL SOLUTION
PLASMA SIMULATION
SIMULATION
THERMONUCLEAR DEVICES
TOKAMAK DEVICES