Supersaturation and nonlinear crash of tokamak sawtooth oscillations

Journal Article · Mon Jul 31 04:00:00 EDT 1989 · Phys. Rev. Lett.; (United States)

DOI:https://doi.org/10.1103/PhysRevLett.63.528· OSTI ID:6026021

Sato, T; Nakayama, Y; Hayashi, T; Watanabe, K; Horiuchi, R

A full-torus, compressible, resistive MHD simulation reveals that in the slow ramp phase of tokamak sawtooth oscillations an ideal kink mode slowly emerges at the magnetic axis as a result of current peaking and gradually expands radially outwards, forming a crescent-shaped poloidal magnetic structure that allows the central /ital q/ value to go substantially below 1. Its converging return flows drive nonlinear reconnection to make two magnetic islands. The kink mode turns into a resistive convection type with a slow but larger growth rate. As the flow grows substantially, a large-scale rigid flow arises and suddenly crashes the plasma structure, forming a crescent-shaped pressure distribution.

• Research Organization: Institute for Fusion Theory, Hiroshima University, Hiroshima 730, Japan (JP); Science Project Corporation, Hiroshima 739-17, Japan
• OSTI ID: 6026021
• Journal Information: Phys. Rev. Lett.; (United States), Journal Name: Phys. Rev. Lett.; (United States) Vol. 63:5; ISSN PRLTA
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700101* -- Fusion Energy-- Plasma Research-- Confinement
Heating
& Production
700107 -- Fusion Energy-- Plasma Research-- Instabilities
CLOSED PLASMA DEVICES
COMPRESSIBILITY
CONVECTION
ENERGY TRANSFER
FLUID MECHANICS
HEAT TRANSFER
HYDRODYNAMICS
INSTABILITY
KINK INSTABILITY
MAGNETIC FIELD CONFIGURATIONS
MAGNETIC FLUX
MAGNETIC ISLANDS
MAGNETOHYDRODYNAMICS
MASS TRANSFER
MECHANICAL PROPERTIES
MECHANICS
NONLINEAR PROBLEMS
PLASMA
PLASMA INSTABILITY
PLASMA MACROINSTABILITIES
PLASMA PRESSURE
PLASMA SIMULATION
RELAXATION
SATURATION
SIMULATION
SUPERSATURATION
THERMONUCLEAR DEVICES
TOKAMAK DEVICES
TORI