Development of an autotuning magnet girder with high stability and accuracy

摘要: With the development of high-performance photon sources which have extremely low emittance,
autotuning magnet girders have drawn more and more attention, especially for diffraction-limited storage
rings and free-electron lasers. The biggest challenge is to simultaneously obtain high stability and high
flexibility. In this paper, an autotuning magnet-girder prototype has been designed and developed.
Topological optimization, multipoint supports, and locking systems have been applied for magnet-girder
design to improve the stability. The modal analysis accords with the vibration test well. The natural
frequency of the magnet-girder assembly is deduced as high as 45.6 Hz, which demonstrates good stability.
Ball-cam movers have been chosen as adjustment mechanisms, and a closed-loop control scheme has been
used to pursue high accuracy. The kinematic resolution is better than 1 μm, and the accuracy is better than
1 μm within the adjusting range of #1;5 mm. Besides, it can eliminate most of the calibration, which can
save much manpower and time. The tests demonstrate that the magnet girder can be used for beam-based
girder alignment with high stability and high accuracy.