LARGE SCALE PARALLEL WAKE FIELD COMPUTATIONS FOR 3D- ACCELERATOR STRUCTURES WITH THE PBCI CODE

A new approach for the computation of short range wake fields for ultra-relativistic bunches in linear accelerators is presented. The method is based on the time domain solution of Maxwell equations for arbitrary 3D- geometry using a purely explicit, split-operator scheme. This approach guarantees the dispersion free propagation of the numerical solution in the longitudinal direction. In addition, it enables wake field simulations on moving computational windows. These ideas have been realized in the development of PBCI; a parallelized, fully 3D- wake field code. Detailed simulation results for several accelerator components, including the TESLA 9-cell structure and a rectangular collimator used in the ILC- ESA test beam experiments are presented.