Variational principle for low-frequency stability of collisionless plasmas

Journal Article · Sat Aug 01 04:00:00 EDT 1981 · Phys. Fluids; (United States)

DOI:https://doi.org/10.1063/1.863550· OSTI ID:6448663

Antonsen, Jr, T M; Lane, B; Ramos, J J

An analysis of the stability of an arbitrary ..beta.. collisionless plasma to modes with wavelengths greater than the ion gyroradius is presented. The stability of such a plasma to perturbations that grow on the hydrodynamic time scale is determined by the Kruskal--Oberman energy principle. However, a configuration which is predicted to be stable on the basis of this kinetic energy principle may still be unstable to modes that grow with a frequency comparable to the diamagnetic or curvature drift frequency. A new variational principle that gives sufficient conditions for instability of these low- frequency modes is derived. The new principle indicates that two types of instabilities are possible; the first corresponds to the low-frequency electrostatic, trapped particles mode, and the second is the low-frequency limit of magnetohydrodynamic (interchange and ballooning) modes. The kinetic modifications to the interchange (Mercier) criterion are evaluated and the effect of the kinetic terms on ballooning modes is estimated.

• Research Organization: Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
• OSTI ID: 6448663
• Journal Information: Phys. Fluids; (United States), Journal Name: Phys. Fluids; (United States) Vol. 24:8; ISSN PFLDA
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700105 -- Fusion Energy-- Plasma Research-- Plasma Kinetics-Theoretical-- (-1987)
700107* -- Fusion Energy-- Plasma Research-- Instabilities
BALLOONING INSTABILITY
COLLISIONLESS PLASMA
DISTURBANCES
FLUID MECHANICS
HYDRODYNAMICS
INSTABILITY
MAGNETOHYDRODYNAMICS
MECHANICS
PLASMA
PLASMA INSTABILITY
PLASMA MACROINSTABILITIES
STABILITY
TRAPPED-PARTICLE INSTABILITY
VARIATIONAL METHODS