Diffusion of charged particles in tokamak-like stochastic magnetic and electric fields

Journal Article · Tue Dec 01 04:00:00 EST 1992 · Physics of Fluids B; (United States)

DOI:https://doi.org/10.1063/1.860349· OSTI ID:6946618

Coronado, M; Vitela E, J ^[1]; Akcasu, A Z ^[2]

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1. Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, A. Postal 70-543, 04510 (Mexico)
2. Department of Nuclear Engineering, The University of Michigan, Ann Arbor, Michigan 48109 (United States)

In this paper the diffusion of guiding centers induced by stochastic magnetic and electric field fluctuations, with both time and space dependence, is analyzed for the case of tokamak plasmas. General experimental results on tokamak fluctuations are used to derive guiding-center equations that properly describe the particle motion. These equations assume uniform average magnetic and electric fields with random stationary Gaussian fluctuations that constitute a homogeneous and cylindrically symmetric turbulence. By applying Novikov's theorem, a Fokker--Planck equation for the probability distribution function is derived and an expression for the guiding-center diffusion coefficient is obtained. This coefficient not only contains the standard terms due to the stochastic wandering of the magnetic lines and the stochastic electric drift, but also new terms due to the stochastic curvature and {del}{ital B} drifts. The form of these terms is shown explicitly in terms of the correlation functions of the fields.

• OSTI ID: 6946618
• Journal Information: Physics of Fluids B; (United States), Journal Name: Physics of Fluids B; (United States) Vol. 4:12; ISSN 0899-8221; ISSN PFBPE
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700330* -- Plasma Kinetics
Transport
& Impurities-- (1992-)
700340 -- Plasma Waves
Oscillations
& Instabilities-- (1992-)
CHARGED PARTICLES
CLOSED PLASMA DEVICES
CORRELATION FUNCTIONS
DIFFERENTIAL EQUATIONS
DIFFUSION
ELECTRIC FIELDS
EQUATIONS
FOKKER-PLANCK EQUATION
FUNCTIONS
GUIDING-CENTER APPROXIMATION
MAGNETIC FIELDS
PARTIAL DIFFERENTIAL EQUATIONS
STOCHASTIC PROCESSES
THERMONUCLEAR DEVICES
TOKAMAK DEVICES
TRANSPORT THEORY
TURBULENCE