Paleoclassical transport in low-collisionality toroidal plasmas

Journal Article · Thu Sep 15 04:00:00 EDT 2005 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.2047227· OSTI ID:20764541

Callen, J D ^[1]

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1. University of Wisconsin, Madison, Wisconsin 53706-1609 (United States)

Radial electron heat transport in a low-collisionality, current-carrying resistive plasma confined in an axisymmetric toroidal magnetic field is hypothesized to be caused by the paleoclassical collisional processes of parallel electron heat conduction and radial magnetic-field diffusion. The electron distribution is Maxwellianized and the electron temperature equilibrated over a long length L (>> the poloidal periodicity half-length {pi}R{sub 0}q) along helical magnetic-field lines that are diffusing radially with the resistivity-induced magnetic-field diffusivity D{sub {eta}}{identical_to}{eta}{sub parallel}{sup nc}/{mu}{sub 0}{approx_equal}{nu}{sub e}(c/{omega}{sub p}){sup 2}. This produces a paleoclassical radial electron heat diffusivity {chi}{sub e}{sup pc} that is a multiple M{approx_equal}L/({pi}R{sub 0}q){approx}10>>1 of the magnetic-field diffusivity: {chi}{sub e}{sup pc}{approx_equal}(3/2)MD{sub {eta}} . New paleoclassical model developments in this paper include full axisymmetric toroidal magnetic-field geometry, evolution of toroidal, poloidal, and helical magnetic fluxes, effects of temporally varying magnetic fluxes, introduction of electron guiding center radial diffusion effects induced by poloidal magnetic-flux diffusion into electron drift kinetics via a Fokker-Planck procedure, and determination of both axisymmetric and the usually dominant helically resonant paleoclassical radial electron heat transport.

• OSTI ID: 20764541
• Journal Information: Physics of Plasmas, Journal Name: Physics of Plasmas Journal Issue: 9 Vol. 12; ISSN PHPAEN; ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
AXIAL SYMMETRY
CHARGED-PARTICLE TRANSPORT
DIFFUSION
DISTRIBUTION
ELECTRON COLLISIONS
ELECTRON DRIFT
ELECTRON TEMPERATURE
ELECTRONS
FOKKER-PLANCK EQUATION
ION COLLISIONS
ION TEMPERATURE
LENGTH
MAGNETIC CONFINEMENT
MAGNETIC FIELDS
MAGNETIC FLUX
PERIODICITY
PLASMA
THERMAL CONDUCTION