April 4-6

Abstract Details

files Add files


Author: Trevor V Taylor
Requested Type: Poster
Submitted: 2022-03-03 12:53:27

Co-authors: E.D. Held, A. Spencer

Contact Info:
Utah State University
Old Main Hill
Logan, UT   84322

Abstract Text:
Wave-particle resonances can have significant effects on plasma stability even in the case of small, resonant sub-populations. In tokamak plasmas, long-wavelength modes interact with the second-adiabatic moment of EPs produced by neutral beams, external RF sources, or fusion-produced alphas. This leads to uncertainty in plasma stability boundaries and enhanced EP particle transport. EP closures based on the PIC algorithm have long been used in extended MHD codes to capture this important physics. The extended MHD code NIMROD has both continuum and delta-f PIC [1] drift kinetic (DK) capability. Serendipity shape functions, up to sixth order, have been implemented in the delta-f PIC DK approach in an attempt to provide more accurate integration of particle trajectories. Such an approach may be vital for accurate integration near the separatrix of a diverted tokamak and for preserving the second-adiabatic invariant. Results from particle integration near separatrix using the Serendipity shape functions, which are compared to the bilinear reduced set often used in NIMROD PIC simulations, are presented. Improvements in accuracy, efficiency, and memory gain when using the serendipity set are also presented.

[1] C. C. Kim, C. R. Sovinec, et.al., Comp. Physics Communications 164, 448 (2004).
This research was supported by the U.S. DOE under grant no. DE-SC0018146 and was performed in conjunction with the Center for Tokamak Transient Simulations (CTTS).