Research on the optimization methods of common points layout for survey and alignment of particle accelerators

Abstract

As a fourth-generation synchrotron light source based on a diffraction-limited storage ring, Hefei Advanced Light Facility (HALF) puts forward higher requirements for the alignment accuracy of the main components. Aggregated common points result in a loss of accuracy during the coordinate transformation required by accelerator alignment. To address this challenge, we proposed two methods: “aggregated points centralization (APC)" and “uniformity-weighted algorithm (UWA)" according to different usage scenarios. APC combines uniformity with the K-means algorithm to enhance the accuracy of coordinate transformation while reducing the number of common points. UWA calculates the uniformity in different directions and assigns weights to common points, reducing the accuracy loss. Simulations demonstrate that these two methods have strong superiority and stability with significantly improved accuracy. Applications of these 2 methods in the magnet unit pre-alignment experiment and tunnel network measurement show promising results. APC in pre-alignment can reduce the cost of building common points by 26% while maintaining the coordinate conversion accuracy. In tunnel network measurement, accuracy can be increased by 28% using UWA. The methods proposed offer broad applicability in the field of particle accelerator alignment and guiding alignment solutions for HALF.