Investigation of ballooning modes in high poloidal beta plasmas in the Tokamak Fusion Test Reactor
- Plasma Physics Laboratory, Princeton University, P.O. Box 451, Princeton, New Jersey 08543 (United States)
Medium-[ital n] (toroidal mode number) instabilities with ballooning characteristics were investigated using x-ray and electron-cyclotron emission (ECE) imaging techniques in the Tokamak Fusion Test Reactor (TFTR) [R. J. Hawryluk [ital et] [ital al]., Plasma Phys. Controlled Fusion [bold 33], 1509 (1991)]. The poloidal mode numbers were determined by fitting the data to soft x-ray signals simulated with a wave-packet model, and the toroidal mode numbers were determined from the phase difference between the soft x-ray and ECE signals. The modes are identified as ideal ballooning modes from the observation that the identified mode numbers are much higher than that of the usual kink or tearing modes, the mode has a strong ballooning characteristic, the growth rate is consistent with the theoretical prediction, and the equilibrium is theoretically predicted to be marginal to the infinite [ital n] ballooning mode. The ballooning mode accompanies a [beta] collapse which happens near the Troyon limit in TFTR. The ballooning mode has also been observed just before a major disruption in TFTR.
- DOE Contract Number:
- AC02-76CH03073; FG02-89ER53297
- OSTI ID:
- 6365081
- Journal Information:
- Physics of Fluids B; (United States), Vol. 5:7; ISSN 0899-8221
- Country of Publication:
- United States
- Language:
- English
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Observation of ballooning instabilities with medium toroidal mode number in high temperature tokamak plasmas
Observation of ballooning instabilities with medium toroidal mode number in high temperature tokamak plasmas
Related Subjects
TOKAMAK DEVICES
BALLOONING INSTABILITY
ELECTRON CYCLOTRON-RESONANCE
INSTABILITY GROWTH RATES
WAVE PACKETS
X-RAY EMISSION ANALYSIS
CHEMICAL ANALYSIS
CLOSED PLASMA DEVICES
CYCLOTRON RESONANCE
INSTABILITY
NONDESTRUCTIVE ANALYSIS
PLASMA INSTABILITY
PLASMA MACROINSTABILITIES
RESONANCE
THERMONUCLEAR DEVICES
700340* - Plasma Waves
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