The new PTB beamline for vacuum-ultraviolet radiometry

At the Metrology Light Source, a 630 MeV electron storage ring for the use of synchrotron radiation for metrology applications, a new beamline is dedicated to radiometry in the vacuum-ultraviolet spectral range. The emphasis lies on the traceability of measurements and profound uncertainty analysis. To replace the previously existing normal incidence monochromator beamline which serviced for more than 20 years now at different facilities, a newly designed 2 m off-plane Eagle monochromator beamline concept was developed. Different reflective coatings for mirrors and gratings in combination with order-sorting filters ensure highest spectral purity of the monochromatized radiation in combination with optimized photon flux characteristics. The beamline is planned to go into full operation in late 2022.