Alignment system for particle accelerators based on a structured laser beam

The Structured Laser Beam (SLB) is a paradigm in the creation of pseudo-non-diffractive optical beams. Its optical intensity profile in the transverse plane is similar to that of a Bessel beam. The SLB has a narrow inner core of high intensity surrounded by concentric circles. One of the interesting properties of the SLB is its ability to propagate over very long distances with a low divergence of the inner core. Assuming a favorable generator design, its divergence is limited to 0.01 mrad. That opens potential applications in different domains, one of them being large-scale metrology and alignment. This thesis will comprise the development of an accurate, optical long-distance alignment system (typically some tens of microns over hundreds of meters). The potential of the SLB will be exploited to propose a novel solution for the alignment of particle accelerators. The system might find application in the Future Circular Collider (FCC). The thesis will include theoretical analyses, numerical simulations and experiments with a prototypical implementation co-developed by the applicant. The thesis will address the subject of laser beam straightness, which will help to evaluate the system performance. The system layout will allow multipoint acquisition along a straight line and meet the criteria of maintenance, radiation and robustness. The performance and useability will be assessed in comparison to existing systems such as the Wire Positioning System (WPS) and Hydrostatic Leveling Systems (HLS).