| Author | Robert Hager, E. S. Yoon, S. Ku, E. F. D'Azevedo, P. H. Worley, C. S. Chang |
|---|---|
| Title | A fully non-linear multi-species Fokker–Planck–Landau collision operator for simulation of fusion plasma |
| Year | 2016 |
| Journal | Journal of Computational Physics |
| Volume | 315 |
| Pages | 644-660 |
| Publisher | Elsevier |
| Abstract | Fusion edge plasmas can be far from thermal equilibrium and require the use of a non-linear collision operator for accurate numerical simulations. In this article, the non-linear single-species Fokker–Planck–Landau collision operator developed by Yoon and Chang (2014) [9] is generalized to include multiple particle species. The finite volume discretization used in this work naturally yields exact conservation of mass, momentum, and energy. The implementation of this new non-linear Fokker–Planck–Landau operator in the gyrokinetic particle-in-cell codes XGC1 and XGCa is described and results of a verification study are discussed. Finally, the numerical techniques that make our non-linear collision operator viable on high-performance computing systems are described, including specialized load balancing algorithms and nested OpenMP parallelization. The collision operator's good weak and strong scaling behavior are shown. |
| DOI Link | doi:10.1016/j.jcp.2016.03.064 |