Bremen 2017 – wissenschaftliches Programm
P 6.9: Poster
Montag, 13. März 2017, 16:30–18:30, HS Foyer
Combining electromagnetic gyro-kinetic particle-in-cell simulations with collisions — •Christoph Slaby, Ralf Kleiber, and Axel Könies — Max-Planck-Institut für Plasmaphysik, D-17491 Greifswald, Germany
It remained an open question whether for electromagnetic gyro-kinetic particle-in-cell simulations pitch-angle collisions and the recently introduced pullback transformation scheme [A. Mishchenko et al., Physics of Plasmas 21, 092110 (2014) and R. Kleiber et al., Physics of Plasmas 23, 032501 (2016)] are consistent.
This question is answered by comparing the PIC code EUTERPE with an approach based on an expansion of the perturbed distribution function in eigenfunctions of the pitch-angle collision operator (Legendre polynomials) to solve the electromagnetic drift-kinetic equation with collisions in slab geometry.
It is shown how both approaches yield the same results for the frequency and damping rate of a kinetic Alfvén wave and how the perturbed distribution function is substantially changed by the presence of pitch-angle collisions.
First results concerning the non-linear saturation of a toroidicity-induced Alfvén eigenmode driven by energetic ions indicate that the saturation level is very sensitive to the collision frequency. The scaling is compared with analytical predictions.