Fast closed orbit control in the SLS storage ring

Abstract

Concepts for a fast orbit feedback in the SLS storage ring are presented. The Singular Value Decomposition (SVD) based orbit correction scheme is supposed to fight orbit oscillations up to 100 Hz stabilizing the orbit to 1/10th of the beam sigma at the locations of the insertion devices. For an emittance ratio of 1%, this corresponds to 1 /spl mu/m tolerance in the vertical plane. In order to achieve this high accuracy strong restrictions are imposed on the residual noise of the beam position monitoring and the correction system. Theoretical estimates for the feedback gain are made using a simplified feedback model. The proposed layout of the feedback electronics based on the SLS digital BPM system is also described.