DESIGN AND PERFORMANCE OF INTRA-TRAIN FEEDBACK SYSTEMS AT ATF2

The major goals of the final focus test beam line facility ATF2 are to provide electron beams with a few tens of nanometer beam sizes and beam stability control at the nanometer level. In order to achieve such a level of stability beam-based feedback systems are necessary at different timescales to correct static and dynamic effects. In particular, we present the design of intra-train feedback systems to correct the impact of fast jitter sources. We study a bunchto- bunch feedback system installed in the extraction line to combat the ring extraction transverse jitters. In addition, we design a bunch-to-bunch feedback system at the interaction point for correction of position jitter due to the fast vibration of the magnets in the final focus. Optimum feedback software algorithms are discussed and simulation results are presented.