SESAME Gets Soft X-Ray Beamline HESEB

On January 9, 2022, the installation of HESEB, the Helmholtz-SESAME Beamline for soft X-ray spectroscopies [1], started at SESAME in Jordan. SESAME was officially founded in 2004 as an international research project under the auspices of UNESCO with multilateral cooperation of members of the Middle East (Cyprus, Egypt, Iran, Israel, Jordan, Pakistan, Palestine, Turkey). After having first light in November 2017, SESAME opened to users the first two beamlines in 2018, dedicated to spectroscopies in the hard X-ray and infrared region. The first scientific paper obtained by SESAME’s photons was published in 2019. At present, SESAME has three active beamlines: XAFS/XRF, IR, and Material Science [2]. In addition to HESEB, a new BEAmline for X-ray Tomography at SESAME (BEATS), funded under the EU H2020 program, is also under construction. In 2019, five research centers of the German Helmholtz Association—DESY, FZJ, HZB, HZDR and KIT—joined forces to implement a state-of-the-art soft X-ray beamline at SESAME. The HESEB project is generously supported with 3.5 M€ from the Initiative & Networking Fund of the Helmholtz Association. HESEB is the first soft X-ray beamline at SESAME and will significantly expand the research capabilities available to the Middle East user community. The project is led by DESY, and the contract for building the beamline was awarded to the FMB-Berlin company. The source is a refurbished BESSY-II UE56 APPLE-II undulator provided by Helmholtz Center Berlin (HZB). The provision of both circularly and linearly polarized light is very suitable for materials science applications, especially for magnetic materials. The plane grating monochromator uses exchangeable gratings to cover a photon energy range from 70 eV to 2000 eV. Figure 1 shows the placing of the monochromator chamber on its support during the installation of the beamline in SESAME. The optical design of HESEB provides two branches in the monochromatic beam for different experimental stations. The day-one instrument, designed and produced by the HESEB project team, allows for X-ray absorption and fluorescence studies. In a special configuration, an X-ray capillary is used to focus the beam further (e.g., for micro-XANES and also to study samples in helium atmosphere, which is suitable for the investigation of delicate items in cultural heritage rvesearch). The commissioning of the beamline and its first end station is expected to occur in early summer 2022. For the second branch, Turkey has approved a project led by the Turkish Energy, Nuclear and Mineral Research Agency (TENMAK) to implement a Turkish soft X-ray Photo-Electron Spectroscopy (TXPES) end station. n