Welcome to the GKW wiki
GKW (Gyro-Kinetic Workshop) is a dedicated software tool for the study of turbulence in a tokamak core plasma, in the local limit as well as over a finite radial domain. It includes (but is not limited to)
- the full toroidal geometry of the tokamak (for a real MHD equilibrium through an interface with the CHEASE code) or Miller parameterisation
- kinetic electrons and an arbitrary number of ion species
- electro-magnetic effects; both perturbations in the vector potential parallel as well as perpendicular the background magnetic field.
- collisions, both pitch angle scattering as well as energy scattering
- background ExB shear
- toroidal plasma rotation effects: both the Coriolis as well as the centrifugal force.
For a complete description of the code, please see the following paper: The nonlinear gyro-kinetic flux tube code GKW, A.G. Peeters, Y. Camenen, F.J. Casson, W.A. Hornsby, A.P. Snodin, D. Strintzi and G. Szepesi, Computer Physics Communications, 180, 2650 (2009)
One strength of GKW is that very good documentation is provided with the code. This extensive documentation, based on the reference above, contains a complete description of the gyrokinetic model as implemented, practical tips on compiling and running GKW, and example input files.
GKW is written in Fortran 95. It has been designed to run on the present high end computing facilities, and with pure MPI scales well up to 8192 cores (80% efficiency against 95% efficiency obtained for 1024 cores). Hybrid parallelism including OpenMP is also implemented, which can allow the code to efficiently scale 2-4x further for some problems and hardware.
Participation in this project is welcome. Just contact any of us.
This wiki contains practical and technical notes, hints and tips, as well as information on publications using GKW.