The 36-cell structure-calculations and experiments

The wake field effects in accelerator sections for future linear colliders will be reduced either by damping, by detuning or a combination of both. In the case of the DESY S-Band Test Facility it is foreseen to employ two higher order mode (HOM) damped cells within a detuned stack of undamped ones. In order to obtain optimal performance by use of single cell dampers a design was derived by applying numerical tools. To understand the behaviour of such a damper cell in a detuned structure, a damper cell was built and inserted in a strongly detuned 36-cell S-band structure. This structure was investigated by bead pull measurements. The predictions of MAFIA field calculations were compared to experimental results.