Speaker
Description
The Future Circular Collider (FCC) is a proposed next-generation collider at CERN, intended to succeed the High-Luminosity upgrade of the LHC. A key element of this project is the Machine Detector Interface (MDI), which forms the link between the accelerator and the detector and fine-tunes the beams immediately before collision by optimizing beam parameters to maximize luminosity. To achieve the extremely small β* values required for the FCC-ee luminosity goals, the final-focus quadrupoles must be positioned only about 2.4 m from the interaction point, placing them inside the detector volume. Achieving the target luminosity therefore requires the position of these quadrupoles to be measured and continuously monitored with approximately 30 µm precision. The lack of suitable metrological solutions, due to extremely constraining conditions, has motivated the development of a novel application of Frequency Scanning Interferometry (FSI), named IMD-FSI (In-line, Multiplexed and Distributed FSI). IMD-FSI is intended to be deployed as a deformation-monitoring system capable of reconstructing the three-dimensional shape of the monitored structure. This paper reviews the development of IMD-FSI, from the underlying deformation models to the successive prototype generations developed so far, including a half-scale mock-up currently under test, and discusses the remaining validation steps required for deployment in the FCC-ee MDI.
