Mechanical aspects of the design of third-generation synchrotron-light sources

In storage rings of third-generation synchrotron radiation facilities, the positioning tolerances of the elements of the machine are constantly reduced to achieve lower emittance and increased lifetime. This implies increasing positioning and alignment precision that must be preserved over long time-spans. The mechanical engineering approach to meet these requirements is described. The design of the Swiss Light Source storage ring support, positioning and position monitoring systems, the tests done on the respective prototypes, the quality assurance and installation procedures, and the operational experience with these systems are discussed in depth. The applicability of the developed arrangement to beam-based alignment is also illustrated.