GMGPolar

GMGPolar is a performant geometric multigrid solver using implicit extrapolation to raise the convergence order. It is based on meshes in tensor- or product-format. GMGPolar's focus applications are geometries that can be described by polar or curvilinear coordinates for which suited smoothing procedures have been developed. The software offers both, matrix-free and matrix versions of the multigrid scheme.

GMGPolar's main application comes from plasma fusion. Tokamak fusion reactors are promising alternatives for future energy production. Gyrokinetic simulations are important tools to understand physical processes inside tokamaks and
to improve the design of future plants. In gyrokinetic codes such as Gysela, these simulations
involve at each time step the solution of a gyrokinetic Poisson equation defined on disk-like
cross sections. With its node-level parallelism, GMGPolar can efficiently solve a related problem on a Tokamak cross section with a target size between millions and a billion of dofs.