Data analysis, spatial metrology network, and precision realignment of the entire MAX IV linear accelerator

Abstract MAX IV Laboratory is the Swedish national particle accelerator that currently provides the world’s most brilliant X-rays for research. MAX IV Laboratory has two storage rings as well as a 300-meter linear accelerator with hundreds of components not only to be relatively aligned with tight tolerances but also to be absolutely aligned with respect to the global coordinate system of the facility. An advanced particle accelerator of this kind requires high-precision alignment of all its sensitive components through a multiple-stage process. We recognized the need for a full realignment of the linear accelerator due to the beam-based measurements done by our accelerator scientists as well as the expected alignment deflections since its initial alignment in 2015. Partial realignment of an operational facility–in this case, the realignment of the entire linear accelerator–involves serious risks, as it must precisely maintain its consistency with the storage rings and the beamlines of the facility that are already aligned and operational. This paper serves as a guide for large-scale realignment problems that involve surveying, outlier analysis, fiducialization, boundary conditions, solution/optimization of reference-networks, and physical realignment of the components. This work took place over 2 years, where the entire realignment process was successfully carried out and finally verified.