Optical Design of the ATHOS Beamlines at SwissFEL

The Paul Scherrer Institut is currently constructing Athos, its second Free Electron Laser with a photon energy range from 250 eV to 1900 eV and pulse energies up to 8 mJ. A single soft X-ray beamline is attached to the undulator section and distributes the radiation into three branches. The beamline design is based on a variable line space spherical grating monochromator with a grating chamber and two retractable distribution mirrors. An achromatic focusing with individual KB-mirror systems downstream of the exit slits focus the beam to the endstations. The stations can operate alternatively without interfering with each other.