1. Code Name: MAG3D

2. Category: Three-Dimensional Equilibrium

3. Responsible Physicist: C. Z. Cheng

4. Others involved in code development: None

5. One line description: Three-dimensional equilibrium of magnetosphere

6. Computer systems which code runs on: Cray and ALPHA workstation

7. Typical running time (if applicable): 10 - 30 minutes/Cray time.

8. Approximate number of code lines: 10,000 lines

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? It produces magnetic field, plasma current density and pressure data files that can be read by test particle orbit and plasma stability codes.

11. 1-2 paragraph description of code: The MAG3D code computes three-dimensional equilibrium of magnetosphere under different solar wind and interplanetary magnetic field conditions. The code makes use of flux coordinates and solve the force balance equation subject to boundary conditions. The results from this code can be used to understand satellite measurement of magnetic field and particle data.

12. Similar codes to this code, and distinguishing differences: None.

13. Journal References describing code (up to 3): C. Z. Cheng, Geophys. Res. Lett., 22, 2401-2404 (September, 1995).

14. New code capabilities planned for next 1-2 years: To include pressure anisotropy and plasma convection as well as the open field line regions.

15. Code users: C. Z. Cheng, A. T. Y. Lui (APL/JHU)

16. Present and recent applications of code: Space plasma physics.

17. Status of code input/output documentation. Check one: ( ) does not exist ( X ) incomplete ( ) exists

18 Year Code was first used and present frequency of use: Code was first used in 1995. Presently, it is used for studying space plasma physics periodically.

19.Estimate of Man-Years invested in developing code: 1.5 man years.

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

21. Language code is writen in: Fortran

22. Results of intercomparisons with other codes and results of validation against experiments. At present no other codes have same capability to compare with. The results from the code have been compared with analytical theories.