ABSTRACT
FinEstBeAMS (Finnish-Estonian Beamline for Atmospheric and Materials Sciences) is a multidisciplinary beamline constructed at the 1.5â GeV storage ring of the MAX IV synchrotron facility in Lund, Sweden. The beamline covers an extremely wide photon energy range, 4.5-1300â eV, by utilizing a single elliptically polarizing undulator as a radiation source and a single grazing-incidence plane grating monochromator to disperse the radiation. At photon energies below 70â eV the beamline operation relies on the use of optical and thin-film filters to remove higher-order components from the monochromated radiation. This paper discusses the performance of the beamline, examining such characteristics as the quality of the gratings, photon energy calibration, photon energy resolution, available photon flux, polarization quality and focal spot size.
ABSTRACT
The optimized design of multilayer-coated blazed gratings (MLBG) for high-flux tender X-ray monochromators was systematically studied by numerical simulations. The resulting correlation between the multilayer d-spacing and grating blaze angle significantly deviated from the one predicted by conventional equations. Three high line density gratings with different blaze angles were fabricated and coated by the same Cr/C multilayer. The MLBG with an optimal blaze angle of 1.0° showed a record efficiency reaching 60% at 3.1 keV and 4.1 keV. The measured efficiencies of all three gratings were consistent with calculated results proving the validity of the numerical simulation and indicating a more rigorous way to design the optimal MLBG structure.
