SEXTANTS beamline is dedicated to the study of magnetic and electronics properties of solids by polarized soft x-ray elastic and inelastic scattering. The beamline cover the energy range from 50 - 1800 eV (optimized from 70 to 1200 eV).
This will involve two tunable undulators in a medium-length straight section and a monochromator designed to provide a resolving power in excess of 10000 at full throughput in a ~ 20 µm x 80 µm spot at the exit slit. Further, a set of refocusing mirrors (some of them bendable) will be available to focus the beam to three distinct working areas at two branch lines. Switching mirrors will enable the alternate use of the two branch lines. Refocusing optics will be adapted to each experimental technique. A very small vertical spot (~2 µm) will be necessary for high resolution inelastic scattering. A more symmetric spot (80 µm x 50 µm H x V) will provide optimum performance for coherent scattering. Finally, elastic scattering and diffraction experiments can require different conditions. Bendable mirrors will make it possible to adjust the focal distance, spotsize or beam divergence to the specific needs. Many experiments will be dealing with magnetic samples or involving orbital symmetry selection, thus helical undulators providing variable polarization have been specified.
The SEXTANTS beamline offers three experimental technics of soft x-ray scattering:
- Inelastic scattering (IXS)/ Resonant Inelastic x-ray Scattering (RIXS). The spectrometer will have an improved resolving power of up to 8000 and always in excess of 5000 over the energy range 50-1000 eV.
- Magnetic x-ray resonant scattering (XRMS). Low temperature (12K) and Quadrupole magnet with field of 0.2T are available. A versatile reflectometer is also available for dedicated sample environment.
- Imaging by coherent scattering (CXI) and by x-ray Fourier Transform Holography (FTH)
These are photon-in-photon-out resonant techniques, highly appropriate to the assessment of element specific magnetic properties under applied magnetic fields, with tunable bulk versus surface sensitivity.