Results 171 to 180 of about 5,372,216 (210)

Revisiting the validity of quasilinear theory

Physics of Fluids B: Plasma Physics, 1993
The weak turbulence theory of Langmuir waves in a one-dimensional, one-species plasma is discussed. Analytic calculations using the theory of two-point correlations show that in the weak turbulence regime, τac≪min(τtr,γ−1k) (where τac is the field autocorrelation time and τtr is the particle decorrelation time), the nonlinear enhancement of the mode ...
Y.-M. Liang, P. H. Diamond
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An experimental test of quasilinear theory

Physica Scripta, 1989
We give a brief summary of an experimental test of the quasilinear theory of the bump on tail instability. Recent theoretical work has suggested that the quasilinear description of the weak warm beam plasma instability is incomplete. It has been suggested that beam mediated mode coupling effects neglected in standard quasilinear theory play an ...
S I Tsunoda, F Doveil, J H Malmberg
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Revision and Test of the Quasilinear Theory

The Physics of Fluids, 1972
The quasilinear theory is revised analytically and its consequences are tested by a numerical simulation for a one-dimensional periodic electron plasma with discrete electrostatic modes. The theory is formulated for unstable and damped modes and a series of constants of motion derived.
Thomas Burns, Georg Knorr
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Quasilinear Theory for a Tokamak Plasma

Communications in Theoretical Physics, 1986
The gyrokinetic quasilinear equations for an axisymetric geometry are derived including parallel current. A possible application to the generation of currents in a tokamak by lower hybrid waves is discussed.
Wang Zhong-tian, Chen xiao-ping, Qiu Xiao-ming   +2 more
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A new derivation of quasilinear theory

Journal of Plasma Physics, 1970
A new derivation of quasilinear theory for plasma oscillations is given, subject to the neglect of wave-wave interactions. The theory, which applies equally to damping and growing waves, requires that the individual wave resonances be narrow and the electric field spectrum sufficiently broad.
J. P. Klozenberg, Ira B. Bernstein
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Experimental test of quasilinear theory

Physics of Fluids B: Plasma Physics, 1991
The use of the random phase approximation in quasilinear theory has been controversial for some time. For the bump-on-tail instability this approximation leads to the neglect of mode coupling effects mediated by the resonant particles. Recently, it has been argued theoretically and numerically that resonant particle mediated mode coupling effects ...
S. I. Tsunoda, F. Doveil, J. H. Malmberg
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Breakdown of Quasilinear Theory in the Tokamak Edge

Physical Review Letters
In the edge of an L-mode tokamak plasma, particle transport and ion energy transport are shown to follow a strong microturbulence (SMT) scaling, whereas in the plasma core the transport is shown to follow quasilinear turbulence scaling. The dependence of diffusivity on potential fluctuation amplitude is linear in the SMT regime, and quadratic in the ...
Arash Ashourvan, J. Candy
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Oscillation center quasilinear theory

The Physics of Fluids, 1973
A new formulation of the quasilinear theory of weakly turbulent plasmas is presented, which explicitly separates resonant and nonresonant wave-particle interactions from the outset. This is achieved by making a canonical transformation to “oscillation center variables” before attempting to solve the Vlasov equation.
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Limitations of quasilinear transport theory

Physics of Fluids B: Plasma Physics, 1992
The anomalous fluxes are evaluated in the simplest possible geometric situation: drift waves in a shearless slab geometry, in the presence of density and temperature gradients. It is shown that, within the strict quasilinear framework, the linear transport equations relating the fluxes to the thermodynamic forces have serious limitations. Such a linear
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Quasilinear Theory of Hydromagnetic Waves in Collisionless Plasma

The Physics of Fluids, 1968
A quasilinear theory of hydromagnetic waves in nonrelativistic collisionless plasma (with no superthermal “tail”) is derived. It is shown that the time evolution of the space-averaged velocity distribution function of each species is described by a diffusion equation in velocity space, and that this “diffusion” can be split into resonant and ...
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