Kinetic and transport theory near the tokamak edge

Journal Article · Sat Jun 01 04:00:00 EDT 1996 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.871920· OSTI ID:367110

Hazeltine, R D ^[1]; Catto, P J ^[2]

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1. Institute for Fusion Studies, The University of Texas at Austin, Austin, Texas 78712 (United States)
2. Massachusetts Institute of Technology, Plasma Fusion Center NW16-236, 167 Albany Street, Cambridge, Massachusetts 02139 (United States)

Conventional transport orderings employed in the core of a tokamak plasma allow large divergence-free flows in flux surfaces, but only weak radial flows. However, alternate orderings are required in the edge region where radial diffusion must balance the rapid loss due to free streaming to divertor plates or limiters. Kinetic equations commonly used to study the plasma core do not allow such a balance and are, therefore, inapplicable in the plasma edge. Similarly, core transport formulas cannot be extended to the edge region without major, qualitative alteration. Here the necessary changes are addressed. By deriving and solving a novel kinetic equation, distinctive collisional transport laws for the plasma edge are constructed. It is found that the new edge ordering retains the radial diffusion and parallel flow of particles, momentum, and heat to lowest order in the conservation equations. To higher order a surprising form for parallel transport in the scrape-off layer is found, in which the parallel flow of particles and heat are driven by a combination of the conventional gradients, viscosity, and new terms involving radial derivatives. The new terms are not relatively small, and could affect understanding of limiter and divertor operation. {copyright} {ital 1996 American Institute of Physics.}

• Research Organization: Massachusetts Institute of Technology
• DOE Contract Number: FG02-91ER54109; FG03-96ER54346
• OSTI ID: 367110
• Journal Information: Physics of Plasmas, Journal Name: Physics of Plasmas Journal Issue: 6 Vol. 3; ISSN PHPAEN; ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
CONSERVATION LAWS
DIVERTORS
KINETIC EQUATIONS
LIMITERS
PLASMA SCRAPE-OFF LAYER
TOKAMAK DEVICES
TRANSPORT THEORY
WALL EFFECTS