Vibration damping systems for magnet girder assembly at the ESRF

A damping system to reduce storage ring quadrupole magnet vibrations, so-called 'damping link', has been implemented at the ESRF. The damping link is a damping device using viscoelastic material (VEM), installed between the girder and the floor. It was used to attenuate the resonant motion of the magnet girder assembly and to improve the electron beam stability and the X-ray beam stability. Vibration tests and finite element analysis were intensively used to identify the resonant motion of the magnet girder assembly, to optimise the design and to check the performance of the damping links. Efforts have been made in the installation of the latter in order to accommodate the environment in the storage ring tunnel. Vibration tests on the magnet girders before and after installation of damping links showed very satisfactory damping performance. Vibrations of the magnet girder assemblies have been effectively attenuated by a factor of about 5.8.