Journal ArticleDOI
Approximate Fokker–Planck collision operator for transport theory applications
S. P. Hirshman,D. J. Sigmar +1 more
TLDR
In this paper, an analytically tractable approximation for the linearized Fokker-Planck collision operator describing a plasma nearly in thermal equilibrium was developed, which preserves the symmetry properties of the exact collision integral which imply the physical conservation laws, selfadjointness, and the H theorem.Abstract:
An analytically tractable approximation is developed for the linearized Fokker–Planck collision operator describing a plasma nearly in thermal equilibrium. This approximate operator preserves the symmetry properties of the exact collision integral which imply the physical conservation laws, self‐adjointness, and the H theorem. A renormalization procedure is developed to accurately treat collisions between particles of arbitrary masses. For large or small mass ratios, the approximate operator reduces to the standard expansions of the exact operator. In the case of identical particle collisions, the present approximation provides a significant improvement over the ’’model operator’’ previously given in the literature, yet retains the simplicity of former operators necessary for analytic work. The recalculation of the classical transport coefficients with this operator reduces to the solution of a coupled set of algebraic equations and indicates its reliability for use in complex neoclassical transport situations. The neoclassical electrical conductivity calculation demonstrates the new physical features of the approximate operator.read more
Citations
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Journal ArticleDOI
Neoclassical transport of impurities in tokamak plasmas
S.P. Hirshman,D.J. Sigmar +1 more
TL;DR: In this paper, a closed set of moment equations is presented for the time evolution of thermodynamic and magnetic field quantities which results from collisional transport of the plasma and two-dimensional motion of the magnetic flux surface geometry.
Journal ArticleDOI
Neoclassical conductivity and bootstrap current formulas for general axisymmetric equilibria and arbitrary collisionality regime
TL;DR: In this article, a code solving the Fokker-planck equation with the full collision operator and including the variation along the magnetic field line, coupled with the adjoint function formalism, has been used to calculate these coefficients in arbitrary equilibrium and collisionality regimes.
Journal ArticleDOI
Bootstrap current and neoclassical transport in tokamaks of arbitrary collisionality and aspect ratio
TL;DR: In this article, a multi-species fluid model is described for the steady state parallel and radial force balance equations in axisymmetric tokamak plasmas, and the bootstrap current, electrical resistivity and particle and heat fluxes are evaluated in terms of the rotation velocities and friction and viscosity coefficients.
Journal ArticleDOI
Gyrokinetic simulations of turbulent transport
TL;DR: An overview of the gyrokinetic framework and simulations to compute turbulent transport in fusion plasmas can be found in this article, where the main results which have been brought by simulations with regard to transport of fusion devices and fluctuation measurements are discussed.
Journal ArticleDOI
Kinetic calculation of neoclassical transport including self-consistent electron and impurity dynamics
Emily Belli,Jeff Candy +1 more
TL;DR: In this paper, the authors provide a first-principles based calculation of the neoclassical transport coefficients directly from solution of the distribution function by solving a hierarchy of equations derived by expanding the DKE in powers of ρ*i, the ratio of the ion gyroradius to system size.
References
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A Model for Collision Processes in Gases. I. Small Amplitude Processes in Charged and Neutral One-Component Systems
TL;DR: In this paper, a kinetic theory approach to collision processes in ionized and neutral gases is presented, which is adequate for the unified treatment of the dynamic properties of gases over a continuous range of pressures from the Knudsen limit to the high pressure limit where the aerodynamic equations are valid.
Small amplitude processes in charged and neutral one-component systems
TL;DR: In this article, a kinetic theory approach to collision processes in ionized and neutral gases is presented, which is adequate for the unified treatment of the dynamic properties of gases over a continuous range of pressures from the Knudsen limit to the high pressure limit where the aerodynamic equations are valid.
Book
Reviews of Plasma Physics
TL;DR: In this article, Rozhansky et al. studied the relationship between transverse conductivity and the generation of self-consistent electric fields in strongly ionized magnetized plasma.
Journal ArticleDOI
Transport phenomena in a completely ionized gas
Lyman Spitzer,Richard Harm +1 more
TL;DR: In this paper, the effect of mutual electron encounters is considered as a problem of diffusion in velocity space, taking into account a term which previously had been neglected, and the appropriate integro-differential equations are then solved numerically.
Journal ArticleDOI
Fokker-Planck Equation for an Inverse-Square Force
TL;DR: The contribution of the Fokker-Planck equation for the distribution function for gases, due to particle-particle interactions in which the fundamental two-body force obeys an inverse square law, is investigated in this paper.