Focusing optics system for the Time-resolved Molecular Optics (TMO) beam line at LCLS Surface metrology and mirror shape control of bendable mirror system

Nine bendable mirrors will be installed as part of the upgrade to Linac Coherent Light Source. To achieve the target performance, accurate elliptical shapes must be generated with these focusing mirrors to an accuracy in the order of 10(4) to 10(5). We briefly summarize the developmental work including surface metrology via stitching and actuator characterization as well as fitting algorithm to achieve shape control of a KB developmental prototype. The height error of the centerline shape generated by the current system is in the order of 3 nm for a one meter long silicon mirror. The most important limiting factor is metrology due to environmental control.