New tokamak wave mode and its instability

Journal Article · Thu Jul 01 04:00:00 EDT 1982 · Sov. J. Plasma Phys. (Engl. Transl.); (United States)

OSTI ID:5575416

Ivanov, S D; Mazur, V A

A new electrostatic wave mode has been discovered for a tokamak in the parameter region k/sub parallel/..nu../sub T/i<<..omega..<< k/sub parallel/..nu../sub T/e, ..nu../sub i//epsilon-c<<..omega..<<..nu../sub e//epsilon-c; ..omega..<<..omega../sub b/i, k/sub perpendicular/..lambda../sub t/i<<1, where ..omega../sub b/i is the bounce frequency of the trapped ions, and ..lambda../sub t/i is the radial dimension of the drift orbit of these ions. The properties of this new mode are a unique combination of the properties of a drift wave and of a trapped-ion mode. This new mode results in equal measure from trapped ions and slow untrapped ions. Fast untrapped ions do not have an effect because of the particular poloidal structure of the mode: The average value of the perturbed potential along a line of force is zero. This mode is excited by collisions of trapped electrons; magnetic shear, ion collisions, and bounce resonances all have a stabilizing effect on this mode. The mode is stabilized if ..nu../sub e//epsilon-c..omega../sub b/i>2/sup -2/3/ (M/sub i//M/sub e/)/sup 1/6/ if this inequality does not hold, and if the shear is not too great, the mode is unstable.

• Research Organization: Siberian Institute of Terrestrial Magnetism, the Ionosphere, and Radio Wave Propagation, Academy of Sciences of the USSR
• OSTI ID: 5575416
• Journal Information: Sov. J. Plasma Phys. (Engl. Transl.); (United States), Journal Name: Sov. J. Plasma Phys. (Engl. Transl.); (United States) Vol. 8:4; ISSN SJPPD
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700107* -- Fusion Energy-- Plasma Research-- Instabilities
700108 -- Fusion Energy-- Plasma Research-- Wave Phenomena
CLOSED PLASMA DEVICES
INSTABILITY
PLASMA DRIFT
PLASMA INSTABILITY
PLASMA MACROINSTABILITIES
PLASMA WAVES
SHEAR
THERMONUCLEAR DEVICES
TOKAMAK DEVICES
TRAPPED-PARTICLE INSTABILITY