1. Code Name: GSSMG

2. Category: MHD equilibrium

3. Responsible Scientist: Bas Braams

4. Others involved in code development: None

5. One line description: Solve the axisymmetric MHD equilibrium equation by a multigrid method.

6. Computer systems which code runs on: Any.

7. Typical running time (if applicable): A few seconds per calculation.

8. Approximate number of code lines: 3000

9. Does this code read data files from another code? No.

10. Does this code produce data files that can be read by another code? Yes, it produces a flux functio on a mesh.

11. 1-2 paragraph description of code: The code solves the Grad-(Schlueter-)Shafranov equation on a rectangular mesh subject to Dirichlet boundary conditions by use of a multigrid method. The discretization employs a fourth-order accurate compact nine-point stencil. The multigrid algorithm is of the full approximation storage, full multigrid variety and employs adaptive switching criteria.

12. Similar codes to this code, and distinguishing differences:

13. Journal References describing code (up to 3): B. J. Braams: "Magnetohydrodynamic equilibrium calculations using multigrid", in ``Multigrid Methods II'', proceedings of the 2nd European Conference on Multigrid Methods, Cologne, 1985; Springer Verlag, Berlin, 1986.

14. New code capabilities planned for next 1-2 years: None

15. Code users: None

16. Present and recent applications of code: None

17. Status of code input/output documentation. Does not exist, but is simple. Contact the author.

18 Year Code was first used and present frequency of use: 1984/1985. Not in use.

19. Estimate of Man-Years invested in developing code: 0.75

20. Catagories of usage of Code (Check all that apply): (x) application code to do analysis and prediction of experiments ( ) numerical testbed of theoretical ideas (x) physics module to be used in integrated modelling (x) code for machine design

21. Language code is writen in: Fortran-77

22. Results of intercomparisons with other codes and results of validation against experiments. None