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Energy transport modelling including ergodic effects
Author(s) -
McTaggart N.,
Bonnin X.,
Runov A.,
Schneider R.,
Zagorski R.
Publication year - 2004
Publication title -
contributions to plasma physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.531
H-Index - 47
eISSN - 1521-3986
pISSN - 0863-1042
DOI - 10.1002/ctpp.200410004
Subject(s) - discretization , delaunay triangulation , toroid , physics , finite difference , finite difference method , mathematical analysis , mathematics , computational physics , geometry , plasma , quantum mechanics
The effect of ergodization (either by additional coils like in TEXTOR‐DED or by intrinsic plasma effects like in W7‐X) defines the need for transport models being able to describe this properly. A prerequisite for this is the concept of local magnetic coordinates allowing a correct discretization with minimized numerical errors. For these coordinates the full respective metric tensor has to be known. To study the energy transport in complex edge geometries (in particular for W7‐X) we use a finite difference discretization of the transport equations on a custom‐tailored grid in local magnetic coordinates. This grid is generated by field line tracing to guarantee an exact discretization of the dominant parallel transport (this also minimizes the numerical diffusion problem). The perpendicular fluxes are interpolated on cross‐sectional planes (toroidal cuts), where a quasi‐isotropic problem is solved by a constrained Delaunay triangulation (preserving magnetic surfaces where they exist), and discretization. All terms involving toroidal terms are discretized by finite differences. The first tests for W7X and NCSX were successfully performed. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)