1. Code Name: ORBIT3D

2. Category: VIa. Kinetic: Particle Orbits

3. Responsible Physicist: R. B. White

4. Others involved in code development: M. Redi, D. McCune, S. Ethier

5. One line description: Hamiltonian guiding center Monte Carlo with numerical or analytic equilibria for Stellarators.

6. Computer systems which code runs on: all Unix platforms

7. Typical running time (if applicable): 30 sec for 1000 particles 100 transits

8. Approximate number of code lines: ~ 3000

9. Does this code read data files from another code? . Reads Stellarator equilibrium output from VMEC and equilibrium data from mapping codes.

10. Does this code produce data files that can be read by another code? Yes, lost particle data files for analysis

11. 1-2 paragraph description of code: Hamiltonian guiding center particle motion including use of numerical equilibrium and field perturbations for analyzing test particle transport, especially energetic ions; uses flux coordinates; includes electric fields, test particle and collision operator.

12. Similar codes to this code, and distinguishing differences: Tani (Japan), Hively (ORNL), Haegi (Italy), guiding center codes but not Hamiltonian. ORBIT for 2D calculations.

13. Journal References describing code (up to 3): R. B. White and M. S. Chance, Phys. Fluids B, 2455 (1984), R. B. White, Canonical Hamiltonian Guiding Center Variables, Phys Fluids B, 845 (1990), M.H.Redi et.al., Energetic Particle Transport in Compact Quasi axisymmetric Stellarators,Phys. Plas. 6, 3509(1999)

14. New code capabilities planned for next 1/2 years:

15. Code users: M. Redi (PPPL), L.-P. Ku, C. Kessel, I. Zatz (PPPL)

16. Present and recent applications of code: NCSX Design.

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

18 Year Code was first used and present frequency of use: 1999, daily

19. Estimate of Man-Years invested in developing code: 10

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 modelling (x ) code for machine design

21. Language code is writen in: fortran

22. Results of intercomparisons with other codes and results of validation against experiments. See ORBIT.