Feedback stabilization of magnetic islands by rf heating and current drive

Conference · Fri Nov 01 04:00:00 EST 1985

OSTI ID:6192556

Ignat, D W; Rutherford, P H; Hsuan, H

Feedback stabilization of the m = 2 mode in tokamaks would be advantageous for disruption-free operation at low q-values. Stabilization of the m = 1 mode and resulting ''sawteeth'' could lead to substantial increases in the stable ..beta..-value, as well as indirect stabilization of the m = 2 mode, by permitting q(0)-values below unity. Stabilization of these modes at acceptable amplitudes appears possible by feedback-modulated heating or current drive applied to the region within the mode-induced magnetic islands. Current drive offers by far the more efficient mechanism, and it can be accomplished using lower-hybrid or electron-cyclotron radio-frequency (rf) techniques. For the lower-hybrid case, ray-tracing calculations demonstrate the needed localization of the rf power, despite long ray paths in the toroidal direction. Top-launched lower-hybrid waves are favored for localized absorption.

• Research Organization: Princeton Univ., NJ (USA). Plasma Physics Lab.
• DOE Contract Number: AC02-76CH03073
• OSTI ID: 6192556
• Report Number(s): PPPL-2278; CONF-8509192-1; ON: DE86002528
• 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
BETA RATIO
CLOSED PLASMA DEVICES
CURRENT-DRIVE HEATING
ELECTRIC HEATING
ENERGY
FEEDBACK
HEATING
HIGH-FREQUENCY HEATING
JOULE HEATING
LOWER HYBRID HEATING
MAGNETIC FIELD CONFIGURATIONS
MAGNETIC ISLANDS
PLASMA HEATING
Q-VALUE
RESISTANCE HEATING
STABILIZATION
THERMONUCLEAR DEVICES
TOKAMAK DEVICES