1. Code Name: XGC0
2. Code Category: Kinetic edge Transport, Integrated Simulation with MHD and neutrals
3. Primary Developer: S. Ku and C.S. Chang
4. Other Developers and Users: G.Y. Park (NFRI), A. Pankin (Tech-X), S. Parker (U. Colorado), A. Kritz, G. Bateman (Lehigh), S. Parker (U. Colorado), J. Cummings (Caltech), Y.S. Na (Seoul National U.)
5. Short description (one line if possible): Guiding center particle code without turbulence. 3D perturbed B capable. Built-in or DEGAS2 kinetic neutral transport. Automated integrated simulation with Elite and M3D on Kepler/Adios.
6. Computer Language (Fortran77, Fortran90, C, C++, etc) and approx # of lines: Fortran90, approximately 20,000 lines
7. Type of input required (including files and/or output from other codes). Is there any special input preparation system (eg, GUI): EFIT geqdsk file or equivalent.
8. Type of output produced (including files that are read by other codes and sizes of large files and synthetic diagnostics): 1D plasma, neutral, Er, bootstrap and rotation profiles. Poincare B plot.
9. Describe any postprocessors which read the output files: Gnuplot and other graphics interface on eSiMon dashboard at ORNL
10. Status and location of code input/output documentation: Basic documentation exists at http://w3.physics.lehigh.edu/~xgc/
11. Code web site? http://w3.physics.lehigh.edu/~xgc/
12. Is code under version control? What system? Is automated regression testing performed? Under SVN. Automated regression testing not performed.
13. One to two paragraph description of equations solved and functionality including what discretizations are used in space and time: Particle-in-cell based upon LittleJohn-Boozer Lagrangian Equation of Motion, with electron subcycling. R-K or predictor-corrector time advance.
14. What modes of operation of code are there (eg: linear, nonlinear, reduced models, etc ): Full-f or delta-f. Linear or nonlinear collision operations
15. Journal references describing code: G.Y. Park, C.S. Chang, et al, Physics of Plasmas 17, 102503 (2010)
16. Codes it is similar to and differences (public version): A reduced axisymmetric version of XGC1, but enhanced capabilities in neutral, impurity, and MHD-coupled physics
17. Results of code verification and convergence studies (with references): S. Ku, C.S. Chang, and P.H. Diamond, Nuclear Fusion 49, 115021 (2009)
18. Present and recent applications and validation exercises (with references as available): Applied to divertor heat-load studed in JRT2010. Being applied to pedestal physics in JRT2011. Being currently applied to RMP penetration and pedestal response [G.Y. Park, C.S. Chang, et al, Physics of Plasmas 17, 102503 (2010)]
19. Limitations of code parameter regime (dimensionless parameters accessible) : Neutral recycling coefficient needs to be physically reasonable. If too small, then the linearized Monte-Carlo collision operator may not yield convergence and only the nonlinear collision option should be used. If too large, code runs out of memory from exploding particle number.
20. What third party software is used? (eg. Meshing software, PETSc, ...): No commercial software is used for portability. Pspline is needed. Adio library is used in the Adios version.
21. Description of scalability: Code can run on small clusters or on peta-scale HPC
22. Major serial and parallel bottlenecks: MPI communication time at extreme scale
23. Are there smaller codes contained in the larger code? Describe: DEGAS2 is built-in as subroutine
24. Supported platforms and portability: Excellent portability. Problem not yet found in portability.
25. Illustrations of time-to-solution on different platforms and for different complexity of physics, if applicable: Ranges from one day on 16 processor-core cluster on low resolution physics to 10 minutes on 160,000 HPC processor cores for high resolution physics.