Massively Parallel Fokker-Planck Calculations

Abstract

package FPPAC [1,2], which nonlinear multispecies FokkerPlanck collision operator for a plasma in twodimensional velocity space, has been rewritten for the Connection Machine 2. This has involved allocation of variables either to the front end or the CM2, minimization of data flow, and replacement of Crayoptimized algorithms with ones suitable for a massively parallel architecture. Coding has been done utilizing Connection Machine Fortran. Calculations have been carried out on various Connection Machines throughout the country. Results and timings on these machines have been compared to each other and to those on the static memory Cray-2 at the National Magnetic Fusion Energy Computer Center. For large problem size, the Connection Machine 2 is found to be cost-efficient.