The ion temperature gradient instability in a linear machine

Journal Article · Sun Apr 01 04:00:00 EDT 1990 · Physics of Fluids B; (USA)

DOI:https://doi.org/10.1063/1.859309· OSTI ID:6846820

Mathey, O; Sen, A K ^[1]

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1. Plasma Research Laboratory, Columbia University, New York, New York 10027 (USA)

It is shown that anisotropy in the ion temperature gradient has a substantial effect on the ion temperature gradient driven mode. A gradient in the parallel temperature is needed for an instability to occur and a gradient in the perpendicular temperature gradient further enhances the instability indirectly as long as the frequency of the mode is near ion resonance. The physical reason for this important role difference is presented. The Columbia Linear Machine (CLM) (Phys. Rev. Lett. {bold 57}, 1729 (1986)) is being redesigned to produce and identify the ion temperature gradient driven {eta}{sub {ital i}} mode. Using the expected parameters, detailed predictions of the mode characteristics in the CLM have been developed. These include growth rate and real frequency as a function of the azimuthal number {ital m}, the drive parameter {eta}{sub {ital i}} {equivalent to}{ital d}(ln {ital T}{sub {ital i}})/{ital d}(ln {ital n}), and the parallel wavenumber {ital k}{sub {parallel}}. Strong multimode instabilities are expected. Because the ion parallel and perpendicular ion temperature gradients are expected to differ significantly, the roles of {eta}{sub {ital i}{parallel}} and {eta}{sub {ital i}{perpendicular}} are differentiated, and this difference is exploited for a stabilization scheme of the mode. Since all gradients are significantly variable over the expected radial wavelength of the mode, a nonlocal radial differential equation has been derived. With some approximations, this can be reduced to a Weber-type equation, which has been solved.

• DOE Contract Number: FG02-87ER53257
• OSTI ID: 6846820
• Journal Information: Physics of Fluids B; (USA), Journal Name: Physics of Fluids B; (USA) Vol. 2:4; ISSN 0899-8221; ISSN PFBPE
• 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
COLLISIONAL PLASMA
CORRECTIONS
DIFFERENTIAL EQUATIONS
DISPERSION RELATIONS
EQUATIONS
HEATING
HIGH-FREQUENCY HEATING
ICR HEATING
INSTABILITY
INSTABILITY GROWTH RATES
ION TEMPERATURE
ISOTROPY
LINEAR PINCH DEVICES
LOW-BETA PLASMA
MAGNETIC FIELDS
OPEN PLASMA DEVICES
OSCILLATION MODES
PINCH DEVICES
PLASMA
PLASMA DENSITY
PLASMA HEATING
PLASMA INSTABILITY
SLABS
STABILIZATION
TEMPERATURE GRADIENTS
THERMONUCLEAR DEVICES