SVD-based filter design for the trajectory feedback of CLIC

The trajectory feedback of the Compact Linear Collider (CLIC) is an essential mitigation method for\nground motion effects at CLIC. In this paper significant improvements of the design of this feedback are\npresented. The new controller is based on a singular value decomposition (SVD) of the orbit response\nmatrix to decouple the in- and outputs of the accelerator. For each decoupled channel one independent\ncontroller is designed by utilising ground motion and noise models. This new design allows a relaxation of\nthe required resolution of the beam position monitor from 10 to 50 nm. At the same time the suppression\nof ground motion effects is improved. As a consequence, the tight tolerances for the allowable luminosity\nloss due to ground motion effects in CLIC can be met. The presented methods can be easily adapted to\nother accelerators in order to loosen sensor tolerances and to efficiently suppress ground motion effects