Conceptual Design Reports

CDR chapter 13 - Alignment

In order to ensure that the machine components are placed according to the physics requirements, FERMI needs well defined survey and alignment procedures and techniques. Surveys are necessary for placement of components and for support of conventional facilities. ELETTRA has a solid history of quality surveying and engineering. The needs of FERMI will be well served by building on the available infrastructure of reference points and the current observation techniques. All surveys will be based on a single coordinate system integrating the existing surface network and storage ring surveys. Components that have been carefully fiducialized can then be installed and aligned using a series of steps from the ground up and later checked with a survey map. The linac area needs special attention, both for the quality control of the accelerator sections and for the alignment methods to be applied in the field. The alignment coordinate system is a Cartesian right-handed system, with the origin placed at a particular point in the beamline. A three-dimensional network methodology is proposed, with the FERMI network integrated with that of the existing ELETTRA storage ring. The instrumentation will include theodolites, total stations, laser trackers and precise levels. The areas to be aligned are the injector, linac, undulator, photon beamlines and experimental hall. The tolerances for the injector, linac and undulator components, 100 μm rms, are achievable with established techniques. The fine adjustment to the BPM and quadrupole positions in the undulator will be done via the beam-based alignment technique described in Chapter 7. The components of the experimental hall have relatively loose alignment requirements, and traditional measuring techniques like those currently in practice at ELETTRA can be used for the placement of components. Retrieve pdf