TEMF, TU Darmstadt, Darmstadt
DESY, Hamburg
The rf and wakefield transverse kicks resulting from the asymmetry of input and HOM couplers in the third harmonic module for the XFEL are investigated. The fundamental mode is computed using eigenvalue analysis. The short range wakefields in a string of cavities are simulated with the PBCI code. Using the simulation data, the transverse kick factors associated with the presence of cavity couplers are evaluated.
* P. Pierini, "Third Harmonic Superconducting Cavity Prototypes for the XFEL", LINAC08.
** T. Khabiboulline, "New HOM Coupler Design For 3.9 Ghz Superconducting Cavities At FNAL", PAC07.
Uni HH, Hamburg
DESY, Hamburg
Based on TE/TM splitting algorithm a new (longitudinally) dispersion-free numerical scheme is developed to evaluate the wake fields in structures with finite wall conductivity. The impedance boundary condition in this scheme is modeled by the one dimensional wire connected to boundary cells. A good agreement of the numerical simulations with the analytical results is obtained. The developed code allows to calculate multipole wake potentials of arbitrary shaped geometries with walls of finite high conductivity.