High-flux and high-resolution spectroscopic facility in the VUV region at Super-ACO

A new spectroscopic facility, consisting of a planar/helical undulator and a 6.65 m off-plane Eagle monochromator, has been designed. It can supply high-flux and high-resolution photons with `exotic' polarization in the 5-40 eV energy range. The astigmatism can be compromised by horizontally focusing the incident radiation on the grating. The rotation of a post-focusing toroidal mirror compensates for the deviation of the exit beam caused by the grating translation. The whole system will be installed at beamline SU5 of SUPER-ACO (0.8 GeV) at the beginning of 1998. With a 4300 grooves mm^-1 grating, a resolving power of around 10⁵ is expected at 20 eV.