JET-P(92)42
3D Fokker-Planck Calculations of Electron and Ion Distributions in Tokamak Plasmas
Two 3D Fokker-Planck codes which calculate distribution functions in velocity and real space allowing for particle trapping, collisions, heating and radial transport in axisymmetric tokamaks, are described. The first, BANDIT-3D, is mainly used for calculating the influence of RF heating on the electron distribution and uses a two stage operator splitting algorithm. The second, FPP-3D, is currently being developed and uses a two cycle, six stage operator splitting algorithm to solve for neoclassical particle distributions. These algorithms are found to be efficient and robust allowing solution of 3D Fokker-Planck equations in modest CPU times on both a CRAY-2 supercomputer and high performance workstations.