Section: New Results

TARGET

Participants : Nicolas Bouzat, Guillaume Latu, Camilla Bressan, Michel Mehrenberger, Virginie Grandgirard.

TArgeting Realistic GEometry in Tokamak code gysela

The framework of the work in [16] is the Semi-Lagrangian setting for solving the gyrokinetic Vlasov equation and the Gysela code. A new variant for the interpolation method is proposed that can handle the mesh singularity in the poloidal plane at $r=0$ (a polar system is used for the moment in Gysela). A non-uniform meshing of the poloidal plane is proposed, instead of a uniform one, in order to save memory and computations. The interpolation method, the gyroaverage operator, and the Poisson solver are revised in order to cope with non-uniform meshes. A mapping that establishes a bijection from polar coordinates to more realistic plasma shapes is used to improve the realism. Convergence studies are provided to establish the validity and robustness of our new approach. This work has been initiated at CEMRACS 2016.