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Neoclassical transport in the presence of radiofrequency fields
Nuclear Fusion, 1989The neoclassical fluxes induced by a radiofrequency field are calculated using the gyrokinetic equations. In general, the fluxes consist of a convective part and a diffusive part. The convective part is non-vanishing when the heating is asymmetric with respect to the magnetic field.
S.C. Chiu, V.S. Chan
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Neoclassical Transportation in the ELMO Bumpy Torus
Physical Review Letters, 1978In the ELMO bumpy torus, neoclassical transport coefficients depend critically on the ambipolar electric field. These coefficients, calculated for arbitrary radial electric fields, are applied in a one-dimensional radial-transport calculation which, for the first time, treats the electric field self-consistently.
E. F. Jaeger, D. A. Spong, C. L. Hedrick
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Neoclassical transport in the presence of fluctuations
Nuclear Fusion, 1992The usual argument for automatic ambipolarity of neoclassical particle fluxes in a tokamak is based on the averaged toroidal momentum equation. It does not apply when fluctuations are present, because they also contribute to the momentum. The finite Larmor radius pressure tensor produced by electrostatic fluctuations makes a small contribution to the ...
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Non-ambipolar neoclassical transport
Nuclear Fusion, 1995The usual demonstration that neoclassical transport is automatically ambipolar, and independent of the radial electric field (Er), is shown to be valid only in an equilibrium axisymmetric plasma in which there is no other source or damping of toroidal momentum.
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Neoclassical Transport In The Stellarator And Heliotron
1998Abstract In neoclassical diffusion theory, the essential mechanism is the existence of a trapped particle with a velocity component perpendicular to the magnetic surfaces due to VB drift motion. From this point of view, neoclassical diffusion exists even in straight stellarators with perfect helical symmetry.
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Drift-Kinetic Simulations of Neoclassical Transport
AIP Conference Proceedings, 2008We present results from numerical studies of neoclassical transport for multi‐species plasmas. The code, NEO, provides 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 fundamental drift‐kinetic equation in ...
E. A. Belli +4 more
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On the relation between neoclassical transport and turbulent transport
Physics of Plasmas, 2005It is demonstrated through the flux-force relationship in the neoclassical theory that when neoclassical transport fluxes are improved, the damping rate of the radial electric field of the zonal flow is reduced. This, in turn, leads to improved turbulent transport fluxes.
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Neoclassical transport in a rotating impure plasma
Physics of Plasmas, 1998In a toroidally rotating tokamak plasma, heavy impurity ions accumulate on the outside of each flux surface under the action of the centrifugal force. The collision frequency therefore varies over the flux surface. This circumstance is shown to enhance the neoclassical transport processes, including the bootstrap current, by making collisions occur ...
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Neoclassical Bootstrap Current and Transport in Optimized Stellarator Configurations
Physics of Fluids B, 1993J Nührenberg, W Lotz, H Maassberg
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