Orthogonal grid construction for modeling of transport in tokamaks

A simple method has been developed for numerically constructing orthogonal grids based on the tokamak poloidal flux surfaces. The poloidal flux surfaces form a natural set of coordinate lines for the study of transport in the tokamak scrape-off region, since the energy transport there is mostly along the field lines contained within the flux surfaces. For a study of both the poloidal and perpendicular (radial) transport, a two-dimensional, preferably orthogonal, mesh is required. The need for a new mesh generating code arose from the requirements of the particular topology produced by the zeros in the poloidal field (x-points) and the consequent problems with the numbering of the mesh. copyright 1987 Academic Press, Inc