ITG instabilities and transport studies in the Columbia Linear Machine

Conference · Sun May 01 04:00:00 EDT 1994 · AIP Conference Proceedings (American Institute of Physics); (United States)

OSTI ID:6930415

Sen, A K; Chen, J; Song, B; Greaves, R G ^[1]

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1. Plasma Research Laboratory, Columbia University, New York, New York (United States)

Both the slab and toroidal branches of the ion temperature gradient (ITG) driven instabilities have been studied in the Columbia Linear Machine (CLM). The ITG instabilities are observed as [ital m]=2 modes when a sufficient parallel ion temperature gradient is reached by using either d.c. ion acceleration heating or rf-transit time heating methods. The slab branch, [ital m]=2 mode, is identified as the ITG mode based on the four basic characteristics predicted by most theoretical work. The toroidal ITG mode is studied by starting with the slab ITG mode and gradually turning on the mirror current in CLM. The curvature effect is shown to further destabilize the mode and reduce the real frequency in the laboratory frame. The experimentally measured features in the presence of the ion temperature gradient and the mirror field also correspond closely to the theoretical predictions of a newly postulated hybrid ITG-dissipative trapped electron drift mode. The anomalous local ion thermal conductivities due to the slab mode has been measured via a temperature relaxation method. Its average value of 0.5 m[sup 2]/sec is about 3 orders of magnitude larger than the classical and 1 order of magnitude lower than the Bohm.

• OSTI ID: 6930415
• Report Number(s): CONF-9301107--
• Conference Information: Journal Name: AIP Conference Proceedings (American Institute of Physics); (United States) Journal Volume: 284:1
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700340* -- Plasma Waves
Oscillations
& Instabilities-- (1992-)
CLOSED PLASMA DEVICES
COLUMBIA HIGH-BETA TOKAMAK
CONFINEMENT
ELECTRON TEMPERATURE
ELEMENTS
HYDROGEN
INSTABILITY
ION DENSITY
ION TEMPERATURE
NONMETALS
PHYSICAL PROPERTIES
PLASMA CONFINEMENT
PLASMA INSTABILITY
TEMPERATURE GRADIENTS
THERMAL CONDUCTIVITY
THERMODYNAMIC PROPERTIES
THERMONUCLEAR DEVICES
TOKAMAK DEVICES