Page 12 - Electrostatic quasi-neutral formulation of global cross-separatrix particle simulation in field-reversed configuration geometry

Physics of Plasmas ARTICLE
FIG. 11. Comparisons of electron dynamics are shown: (a) R-Z trajectory in the poloidal plane with corresponding simulation meshes shown in matching colors, (b) parallel vs perpendicular velocity, (c) toroidal phase space, and (d) weight evolution over time. Four different tracked electrons (ip is the tracking label of the particle) are shown for the one direct calculation case and the three mesh-to-particle interpolation cases.
In general, the ANC field-aligned mesh operations also impose zero on the machine axis. This causes a slight discrepancy in the com- parison of the partial derivative with respect to the axial position.
B. Mesh to particle interpolation
Using a test function for the electric field, comparisons are made for electron dynamics. The “grid interp.” results are updated using
electric field components interpolated onto particles using field-aligned mesh operations while “direct calc.” results are updated using electric field components directly calculated from the analytic test function. Three different grid resolutions are used in the case of “grid interp.,” with the cell shapes being shown in corresponding colors in (a) of Fig. 11. Electrons are tracked near the turning points of the core where the most concern may be for stretched meshes; these electrons cross multiple simulation cells in this benchmark.
scitation.org/journal/php
Phys. Plasmas 27, 082504 (2020); doi: 10.1063/5.0012439 Published under license by AIP Publishing
27, 082504-12