A dispersionless algorithm for calculating wake potentials in 3D

Accurate computations of wake potentials are an important task in modern accelerator design. Short bunches used in high energy particle accelerators excite very high- frequency fields. The geometrical size of accelerating structures exceeds the wavelength of the excited fields by many orders of magnitude. The application of codes such as TBCI, MAFIA[1] or tamBCI are limited due to numerical dispersion effects and memory needs. Recently new codes like PBCI have been developed to overcome these problems. In this work the utilization of dispersionless directions in the leap-frog update scheme on a Cartesian grid are proposed for accurate simulations. In conjunction with a conformal modeling technique which allows for the full Courant time step a moving window technique can be applied. This was previously implemented in a 2D code [2]. In this publication an extension to arbitrary three dimensional problems is presented.