Wakefield Computations with the PBCI Code Using a Non-Split Finite Volume Method

We report on a new numerical technique for the computation of geometrical wakes in three-dimensional LINAC structures. The method utilises an explicit Finite-Volume Time-Domain (FVTD) formulation. The numerical dispersion in all three axial directions is completely eliminated by choice of an appropriate staggering of the field components on the grid. Thus, contrary to most of the previously reported techniques no splitting of the time-evolution operator is necessary. This results in large savings in computational time as well as in an improved numerical accuracy. We have implemented this new technique in the PBCI code and present some preliminary results.