The X06DA-PXIII beamline at the Swiss Light Source, operating since 2008 and contributing to over 2650 crystal structures, has been fully rebuilt to harness the reduced emittance and improved performance of the SLS 2.0 storage ring. Its new optical design, featuring a toroidal mirror close to the source, horizontal 1:2 focusing, and a Kirkpatrick–Baez mirror system, enables efficient photon collection and tight beam focusing and thus improves overall efficiency.

A start-to-end FEL pulse propagation method has been developed to evaluate grating monochromator performance, quantifying the impacts of longitudinal source jitter, finite-aperture diffraction, and thermal deformation on resolving power, thereby offering realistic guidance for FEL beamline design and optimization.

This work develops a 6D phase space tracing module in the FURION software. The 6D phase space tracing provides a solution for the rapid simulation of ultrashort pulse propagation in X-ray beamlines, especially in dispersive beamline systems.

This work presents the design and expected performance of an Angle-Resolved Photoemission Spectroscopy (ARPES) branchline at the Shenzhen Superconducting Soft X-ray Free Electron Laser (S3FEL). The branchline employs a symmetric time-delay-compensated monochromator (TDCM) for spectral selection and pulse duration preservation. Numerical optimization using the six-dimensional K-matrix method and Fourier optics simulation shows that the TDCM can achieve a time–bandwidth product approaching the Fourier-transform limit.