Negative-energy modes in a magnetically confined plasma in the framework of Maxwell-drift kinetic theory

Journal Article · Fri Apr 01 04:00:00 EST 1994 · Physical Review. E, Statistical Physics, Plasmas, Fluids, and Related Interdisciplinary Topics; (United States)

DOI:https://doi.org/10.1103/PhysRevE.49.3290· OSTI ID:5145661

Throumoulopoulos, G N; Pfirsch, D ^[1]

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1. Max-Planck-Institut fuer Plasmaphysik, EURATOM Association, D-85740 Garching (Germany)

For the cases of tokamaklike and shearless stellaratorlike equilibria, which are described on the basis of, respectively, a slightly modified Maxwellian and a Maxwellian distribution function, the existence of perpendicular negative-energy modes is related to the threshold value 2/3 of the quantity [eta][sub [nu]]=[partial derivative] ln[ital T][sub [nu]]/[partial derivative] ln[ital N][sub [nu]], where [ital T][sub [nu]] is the temperature and [ital N][sub [nu]] the density of some particle species. This is lower than the critical [eta][sub [nu]] value for the onset of [ital linear] temperature-gradient-driven modes. For various tokamaklike and stellaratorlike, analytic cold-ion equilibria with non-negative and negative values of [eta][sub [ital e]], for which the criterion above is not necessary, a substantial fraction of thermal electrons is associated with negative-energy modes (active particles). In particular, for linearly (marginally) stable equilibria with [eta][sub [ital e]]=1, nearly one-third of the electrons are active. For all equilibria considered, the phase space occupied by active electrons increases as one proceeds from the center to the plasma edge region. Consequently, negative-energy modes, relating to nonlinear instabilities that could cause anomalous transport, exist equally well in both confinement systems.

• OSTI ID: 5145661
• Journal Information: Physical Review. E, Statistical Physics, Plasmas, Fluids, and Related Interdisciplinary Topics; (United States), Journal Name: Physical Review. E, Statistical Physics, Plasmas, Fluids, and Related Interdisciplinary Topics; (United States) Vol. 49:4; ISSN 1063-651X; ISSN PLEEE8
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700310* -- Plasma Confinement-- (1992-)
CLOSED PLASMA DEVICES
COLLISIONLESS PLASMA
CONFINEMENT
DIFFERENTIAL EQUATIONS
ENERGY LEVELS
EQUATIONS
EQUILIBRIUM
INSTABILITY
KINETICS
MAGNETIC CONFINEMENT
MAXWELL EQUATIONS
NEGATIVE ENERGY STATES
PARTIAL DIFFERENTIAL EQUATIONS
PLASMA
PLASMA CONFINEMENT
STELLARATORS
THERMONUCLEAR DEVICES
TOKAMAK DEVICES