A new VUV high resolution undulator-based beamline at Super-ACO

The VUV undulator-based high resolution SU5 beamline, designed to operate in the 5-45 eV photon energy range, is under construction at Super-ACO. It is composed of three toroidal mirrors around a 6.65 m Eagle off-plane normal incidence monochromator, whose induced-astigmatism is negligible owing to an horizontal focusing onto the gratings. With an optical design minimizing the aberrations and optimizing the throughput through the entrance slit, and with a careful choice of the optical coatings, the SU5 beamline should provide in the near future more than 1010 ph/s at the sample level for a 1/50000 bandwidth in the 5-25 eV energy range. The ultimate resolving power should be higher than 105. (orig.)