A NEW VUV HIGH-RESOLUTION UNDULATOR-BASED BEAMLINE AT SUPER-ACO

The VUV undulator-based high resolution SU5 beamline, designed to oper ate in the 5-45 eV photon energy range, is under construction at Super -AGO. It is composed of three toroidal mirrors around a 6.65 m Eagle o ff-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 throughpu t through the entrance slit, and with a careful choice of the optical coatings, the SU5 beamline should provide in the near future more than 10(10) ph/s at the sample level for a 1/50000 bandwidth in the 5-25 e V energy range. The ultimate resolving power should be higher than 10( 5). (C) 1998 Elsevier Science B.V. All rights reserved.