Simulation-driven analysis and optimization of beamline optics performance for the APS upgrade

Abstract

The Advanced Photon Source Upgrade (APS-U) delivers much higher brightness and coherence, which places far tighter tolerances on beamline optics. As a result, simulation has become essential for understanding performance limits, diagnosing optics-related problems, and guiding optimization under realistic conditions. Here, numerical modeling is used to study optics issues caused by thermal load, mechanical instability, figure error, misalignment, and wavefront degradation. Several beamline case studies are examined, including a white-beam mirror with thermal deformation from finite-element analysis, transfocator systems affected by measured lens errors and misalignments, and nano-focusing KB mirror systems with strict alignment tolerances and scattering tails. Together, these examples show that simulation is not only a design tool, but also a practical method for diagnosing and improving real beamline performance.