GTS

1. Code Name: Gyrokinetic Tokamak Simulation code (GTS)
2. Code Category: GK-PIC
3. Primary Developer: Weixing Wang
4. Other Developers and Users: Stephane Ethier, Robert Preissl (NERSC/LBL), Jugal Chowdhury
5. Short description (one line if possible): Global, gyrokinetic PIC code in full general geometry used for studying core microturbulent transport in experimental tokamaks
6. Computer Language (Fortran77, Fortran90, C, C++, etc) and approx # of lines.: Fortran 90 and C, 18,000 lines
7. Type of input required (including files and/or output from other codes). Is there any special input preparation system (eg, GUI)
  • TRANSP profiles from experimental shot
  • Reconstructed magnetic equilibrium (from JSOLVER or ESC)
  • Run parameter file > Equilibrium electric field from GTC-NEO simulation (optional)
  • PETSc parameter file
8. Type of output produced (including files that are read by other codes and sizes of large files and synthetic diagnostics):
  • Volume averaged time-dependent quantities
  • Flux surface averaged quantities
  • Whole grid potential and density fluctuations written out at regular intervals, which can be fed into
  • Various distribution functions in chosen locations (input parameters)
9. Describe any postprocessors which read the output files:
  • Many hand-coded MATLAB scripts:
  • Old in-house IDL post-processor for time-dependent data and snapshots
  • Synthetic diagnostic of tangential scattering measurement (developed by F. Poli) reads in the density fluctuation files
10. Status and location of code input/output documentation: No formal documentation
11. Code web site? Under construction
12. Is code under version control? What system? Is automated regression testing performed? Code under subversion (SVN) version control, No automated regression testing
13. One to two paragraph description of equations solved and functionality including what discretizations are used in space and time:
14. What modes of operation of code are there (eg: linear, nonlinear, reduced models, etc ):
  • Nonlinear with adiabatic electrons
  • Nonlinear with kinetic electrons
  • With experimental profiles and reconstructed equilibrium
  • With model equilibrium and profiles
15. Journal references describing code: W.X. Wang et al., Phys. Plasmas 13, 092505 (2006); W.X. Wang et al., Phys. Plasmas 17, 072511 (2010)
16. Codes it is similar to and differences (public version):
17. Results of code verification and convergence studies (with references):
18. Present and recent applications and validation exercises (with references as available):
19. Limitations of code parameter regime (dimensionless parameters accessible): Limited to core plasma, Microturbulence time scale
20. What third party software is used? (eg. Meshing software, PETSc, ...): PETSc, PSPLINE, SPRNG 2.0
21. Description of scalability: Excellent particle scaling to largest number of cores on Cray XT5
22. Major serial and parallel bottlenecks: Memory gather-scatter intrinsic to PIC method
23. Are there smaller codes contained in the larger code? No.
24. Supported platforms and portability: Highly portable (Cray XT systems, Linux clusters)
25. Illustrations of time-to-solution on different platforms and for different complexity of physics, if applicable.