RXES endstation

The MagneDyn beamline at the Fermi free electron laser, Rev. Sci. Instrum. 93, 115109 (2022); https://doi.org/10.1063/5.0105261

The experimental setup for time-resolved RXES/RIXS at the MagneDyn facility consists of an upgraded version of the previously developed time-resolved RIXS setup. Located in the second experimental area, this end-station enables pump-probe experiments with sub-eV energy resolution. The setup, as illustrated in the schematic, features an incoming FEL beam that is scattered by the sample, with the scattered radiation collected by a spectrometer placed at a 90-degree angle. The scattering angle of incidence can be adjusted between 0 and 90 degrees, while the in-plane X-Y directions help align the sample with the FEL and spectrometer foci.
The spectrometer incorporates three spherical gratings in a Rowland geometry, which are set in the plane of the horizontal FEL polarization. Offering an overall resolution of approximately 100 meV at 70 eV and up to 600 meV at 300 eV, the resolution is determined by either a pair of slits or the vertical dimension of the FEL focus in a slitless configuration.
Finally, the radiation is captured by a 2D detector, which comprises a double-stack multi-channel plate activated for UV and X-rays by CsI. The detector is read out by a resistive anode and subsequently imaged by a CCD. This experimental setup provides the necessary capabilities for conducting advanced time-resolved RXES/RIXS studies at the MagneDyn facility.