Beamline mirrors and monochromator for X-ray free electron laser of SACLA

Beamline mirrors and a monochromator were developed as key optical devices for the Japanese XFEL facility, SPring-8 Ångstrom Compact Free Electron Laser (SACLA). The optics were designed for transporting extremely intense, transversely coherent XFEL light to the experimental stations. The mirror system delivers a pink beam with high intensity and an energy range below 15 keV, while the monochromator with Si (1 1 1) covers wider energy range of 4–30 keV with 0.01% bandwidth. For realizing high stability and contamination-free environment, the mechanics of these optical components were designed to have high stiffness with ultra-high vacuum (UHV) compatibility. After 100 days of operation, no radiation damage was observed on the mirror surfaces.