On description of magnetic stochasticity in poloidal divertor tokamaks

Journal Article · Tue Apr 15 04:00:00 EDT 2008 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.2907163· OSTI ID:21120256

Abdullaev, S S; Jakubowski, M; Lehnen, M; Schmitz, O; Unterberg, B ^[1]

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1. Institut fuer Energieforschung-Plasmaphysik, Forschungszentrum Juelich GmbH, EURATOM Association, Trilateral Euregio Cluster, D-52425 Juelich (Germany)

A generic approach to study the stochastic field lines formed near the magnetic separatrix of poloidal divertor tokamaks due to nonaxisymmetric magnetic perturbations is proposed. The method is based on the determination of the so-called Poincare integral [S. S. Abdullaev, Phys. Rev. E 70, 046202 (2004)] defined as an integral over the vector potential of the perturbation field taken along the closed field lines orbit. This integral allows us to obtain the analytical estimations for the characteristics of chaotic field lines near the magnetic separatrix, like the Chirikov parameter, the widths of the stochastic layer and magnetic footprints, also the statistical characteristics of chaotic field lines, the quasilinear field line diffusion coefficients, and the Kolmogorov lengths. These estimations are in good agreement with the direct numerical calculations of corresponding quantities. A field line convection coefficient is introduced to describe the preferential outward drift of open chaotic field lines near the separatrix.

• OSTI ID: 21120256
• Journal Information: Physics of Plasmas, Journal Name: Physics of Plasmas Journal Issue: 4 Vol. 15; ISSN PHPAEN; ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
CHAOS THEORY
DIFFUSION
DISTURBANCES
DIVERTORS
LAYERS
LENGTH
PERTURBATION THEORY
STOCHASTIC PROCESSES
TOKAMAK DEVICES
VECTORS
WIDTH