Published online by Cambridge University Press: 16 November 2010
Compact linear collider (CLIC) is a study for a future electron–positron collider that would allow physicists to explore a new energy region beyond the capabilities of today's particle accelerators. The demanding transverse and vertical beam sizes and emittance specifications are resulting in stringent alignment and a nanometre stability requirement. In the current feasibility study, the main beam quadrupole magnets have to be actively pre-aligned with a precision of 1 µm in five degrees of freedom before being mechanically stabilized to the nanometre scale above 1 Hz. This contribution describes the approach of performing this active pre-alignment based on an eccentric cam system. In order to limit the amplification of the vibration sources at resonant frequencies, a sufficiently high eigenfrequency is required. Therefore, the contact region between cam and support was optimized for adequate stiffness based on the Hertzian theory. Furthermore, practical tests performed on a single-degree-of-freedom mockup will show the limitation factors and further improvements required for successful integration in a full-scale quadrupole mockup presently under design.