Study of orbit feedback systems for the TESLA Linear Collider

In order to reduce the influence of magnet vibrations which can cause luminosity reduction in the TESLA Linear Collider, several feedback loops are planned to control the beam orbit and to keep the beams in collision. The complete control system for orbit correction can be divided into three different feedback systems: in the main linac a slow feedback system is intended to cancel perturbations in the low frequency range which are mainly due to ground motion. In the beam delivery section a fast feedback system is to be installed to compensate disturbances containing higher frequency components, mainly from pulse-to-pulse quadrupole vibrations and potentially also due to microphonics and Lorentz-force detuning in the superconducting cavities. At the interaction point a fast feedback system will keep the two beams in collision, using the beam-beam-deflection signal. The paper summarizes design studies for all three orbit correction schemes and the main components are discussed in detail