Sensitivity of the kink instability to the pressure profile

Journal Article · Wed Jul 01 04:00:00 EDT 1992 · Physics of Fluids B; (United States)

DOI:https://doi.org/10.1063/1.860029· OSTI ID:7182348

Howl, W; Turnbull, A D; Taylor, T S; Lao, L L; Helton, F J; Ferron, J R; Strait, E J ^[1]

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1. General Atomics, San Diego, California 92186-9784 (United States)

The stability of the {ital n}=1 ideal kink in DIII-D-like (Fusion Technol. {bold 8}, 441 (1985)) configurations is found to depend critically on the details of the current density and pressure profiles. The maximum stable normalized {beta}, {beta}{sub {ital N}}={beta}/({ital I}/{ital aB}) ({ital I} in MA, {ital a} in meters, and {ital B}{sub 0} in tesla), is found to increase dramatically as the peak in the pressure gradient is shifted from the central region toward the plasma boundary. Further, for peaked pressure profiles, the {beta} limit is insensitive to the internal inductance, {ital l}{sub {ital i}}, whereas for broad pressure profiles, the {beta} limit depends more strongly on {ital l}{sub {ital i}} and can increase with {ital l}{sub {ital i}} almost up to the point where the {ital q} profile becomes hollow. With broad pressure profiles and a conducting wall at 1.5 minor plasma radii, kink-stable {beta}{sub {ital N}} values of 5.8{minus}significantly above both the Troyon limit and the ballooning limit{minus}have been found.

• DOE Contract Number: AC03-89ER51114
• OSTI ID: 7182348
• Journal Information: Physics of Fluids B; (United States), Journal Name: Physics of Fluids B; (United States) Vol. 4:7; ISSN PFBPE; ISSN 0899-8221
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700340* -- Plasma Waves
Oscillations
& Instabilities-- (1992-)
700370 -- Plasma Fluid & MHD Properties-- (1992-)
CLOSED PLASMA DEVICES
CURRENT DENSITY
DOUBLET-3 DEVICE
FLUID MECHANICS
HYDRODYNAMICS
INSTABILITY
KINK INSTABILITY
MAGNETOHYDRODYNAMICS
MECHANICS
PLASMA INSTABILITY
PLASMA MACROINSTABILITIES
PRESSURE DEPENDENCE
PRESSURE GRADIENTS
SENSITIVITY
THERMONUCLEAR DEVICES
TOKAMAK DEVICES