Speaker
Description
Located in the heart of the Paris-Saclay university and technology park, SOLEIL is preparing a major upgrade of its machine and beamlines. This project known as SOLEIL II aims to provide a 4th generation synchrotron light source by the end of 2030. The new storage ring will have an emittance of 85 pm.rad which will naturally arise challenging questions about the solutions to be chosen for its alignment. Indeed, simulations carried out by the Accelerator Physics group have shown that the storage ring girders and most of the magnets on a girder must be aligned transversally with a tolerance of +/- 50 µm (normal distribution with 25 µm standard deviation and truncated at 2 sigmas). For more specific components such as magnets on matching straight section girders, the tolerances are decreased to +/- 20 µm (normal distribution with 10 µm standard deviation and truncated at 2 sigmas). Finally, the 354 m circumference of the machine must be maintained to its nominal value at better than +/- 2 mm (normal distribution with 1 mm standard deviation and truncated at 2 sigmas).
Concerning the positioning of the new machine with respect to the actual one, the SOLEIL II project try to minimize as far as possible the modification of the beamline position and orientation that would require beamline realignment. But due to the compacity of the future machine and the technical choices made for the lattice (still under development), some concessions had to be made. Five to six beamlines over the 29 installed at SOLEIL will be relocated around the machine. Dipole-based beamlines will suffer from substantial changes in position and orientation (1° shift in the horizontal plane) and will require a realignment but without modifying the hutch position. Finally, concerning the 13 beamlines based on insertion devices, everything is done to limit their transverse realignment and orientation (less than 1 mm transversally and less than 50 µrad in direction).
The given presentation will provide an overview of the alignment strategy under development at SOLEIL to position the new machine with respect to the actual one and to keep certain beamlines in position. The objective is to avoid any deformation of the theoretical machine. It will also be an opportunity to present current metrological development to better control laser tracker measurement and to keep as low as possible the component alignment uncertainty.
