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[Licence| Download | New Version Template] aatq_v1_0.gz(86 Kbytes)
Manuscript Title: EIV: axisymmetric plasma equilibrium code.
Authors: D.E. Shumaker
Program title: EIV
Catalogue identifier: AATQ_v1_0
Distribution format: gz
Journal reference: Comput. Phys. Commun. 44(1987)177
Programming language: Fortran.
Computer: CRAY-I, CRAY-II.
Operating system: CTSS.
RAM: 42 K words
Word size: 064
Keywords: Plasma physics, Equilibrium, Two-dimensional, Finite elements, Flux surface coordinates, Compact torus, Field-reversed, Configuration, Sspheromak.
Classification: 19.6.

Nature of problem:
This code computes a 2-D axisymmetric equilibrium for a compact torus. The magnetic field structure can consist of both open and closed field line regions which are separated by a separatrix. The scalar plasma pressure and magnetic fields are both determined by the adiabatic quantities, entropy and magnetic fluxes. The outer boundary is assumed to be a flux conserver which can have any reasonable shape.

Solution method:
Since adiabatic quantities are used as inputs, an alternating dimension method is used. The calculation proceeds by alternating between the solution of the 2-D Grad Shafranov equation and the 1-D flux-surface average of this equation. The 1-D calculation determines the volume enclosed by each flux surface. This is needed to determine the pressure on each flux surface from the given entropy function. The 2-D calculation determines the magnetic flux function, Psi, on an approximate flux-surface coordinate system using finite elements and the Galerkin method. With Psi given on this grid, the grid points are then moved so that they form more accurate flux surfaces (surfaces on which Psi is a constant). The 2-D/1-D iteration continues until Psi is a constant on the grid surfaces, thus they are flux surfaces.

Restrictions:
The topology of the magnetic field structure is constrained. The computation region must be bounded by a magnetic flux surface in the radial direction. This surface can be open at the top of the region. The computation region is assumed to be symmetric about the z=0 plane. The magnetic field structure can contain both open and closed field lines or only closed field lines, in which case the separatrix is the outer boundary. The magnetic field structure can contain one o-point and one x-point.

Unusual features:
Plotting subroutines are in a separate file.

Running time:
1 to 4 min.