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Figure 1
Schematic diagram of the beamline apparatus on I20-Scanning, which includes several advanced optical components. X-rays delivered by the wiggler source are deflected upwards by a vertical collimating mirror with rhodium and platinum stripes (M1) to maximize flux, before being downward deflected by the deflecting mirror (M2) to restore the beam's horizontal trajectory and isolate any mirror adjustments. The X-rays then pass through the custom-built Si(111) four-bounce crystal monochromator (4BCM), ensuring the incident X-ray energy is well defined. Vertical and horizontal focusing mirrors (M3, M4) after the monochromator focus the X-rays on the sample position, while a set of harmonic rejection mirrors with rhodium and silicon stripes maintain spectral purity by reducing the content of higher-order harmonics in the X-ray beam before it is incident on the manganese sample. Fluorescent X-rays from the sample are Bragg-reflected by two sets of seven spherically bent and cylindrically sliced Si(440) analyser crystals, angled close to back-scattering. The analysers lie on a Rowland circle of 1 m diameter in the vertical plane, based on Johann-type geometry. Fluorescent photons are directed by the analysers to seven independent regions on each of the two respective Medipix detectors. This setup allows 14 separable and independent measurements of the XR-HERFD signal.

IUCrJ
Volume 12| Part 5| September 2025| Pages 548-562
ISSN: 2052-2525
https://doi.org/10.1107/S2052252525005573