BUNCH TO BUNCH ORBIT FEEDBACK AND LUMINOSITY CONSIDERATIONS OF e-e- INTERACTIONS IN TESLA

Due to the high disruption during e-e- collisions — especially for the recent high luminosity e+e- parameter set — the luminosity is very sensitive to beam instabilities. In order to limit the reduction in luminosity due to beam separations to a few percent, the beam–beam interaction has to be vertically stabilized to within a fraction of the beam spot size of 5 nm. One of the benefits of TESLA is that, due to the large bunch spacing of 337 ns, an orbit correction at the interaction point is feasible on a bunch-to-bunch basis. The design of this feedback system and an improvement of the e-e- luminosity based on the given machine layout are discussed.