Design and optimization of diffraction-limited storage ring lattices based on many-objective evolutionary algorithms

Two diffraction-limited storage ring (DLSR) lattices of ESRF-EBS type with different energies are designed and optimized using three many-objective evolutionary algorithms (MaOEAs) and a widely used multi-objective evolutionary algorithm. The initial population has been found to have a significant impact on the performance of the algorithms, and this impact has been carefully studied. The performance of the four algorithms is compared, and the results demonstrate that the grid-based evolutionary algorithm (GrEA) has the best performance. MaOEAs are applied in many-objective optimization of DLSR lattices for the first time and lattices with the natural emittance of 116 pm∙rad and 23 pm∙rad are obtained at energies of 2 GeV and 6 GeV, respectively, both with reasonable dynamic aperture and local momentum aperture (LMA).