The ForMAX beamline is equipped with two horizontally deflecting monochromators: either a “high-resolution” double crystal monochromator (hDCM) or a “high-flux” double multilayer monochromator (hDMM). The former is the standard monochromator for SWAXS and the latter for full-field microtomography. The beam passes onto dynamically bendable mirrors (VFM and HFM) in Kirkpatrick-Baez geometry, providing harmonic rejection and the possibility for independent focusing/collimation in vertical and horizontal directions. The optics hutch also includes four diagnostics units.
The hDCM and diagnostics units were delivered by FMB Oxford, the hDMM by Axilon, and the focusing mirrors by IRELEC.
Secondary optics will be installed in the experimental station, providing the possibility of further decreasing the beam size to ≈ 1-2 μm or increasing to ≈ 5 mm.
X-ray source | In-vacuum undulator (IVU), 3 m magnetic length, 17 mm period, 166 periods, 4.5 mm minimal magnetic gap. |
Energy range | 8-25 keV, using 3rd-13th harmonics of the IVU. |
Crystal monochromator (hDCM) | Cryo-cooled horizontally deflecting double-bounce Si(111) crystal monochromator with fixed exit. Positioned 27 m downstream of the source. |
Multilayer monochromator (hDMM) | Water-cooled horizontally deflecting double-bounce multilayer monochromator with fixed exit. W/B4C and Ru/B4C coatings. Positioned at 25 m. |
Focusing mirrors | Vertically (VFM; 30.2 m from source) and horizontally (HFM;31 m from source) bouncing mirrors in Kirkpatrick-Baez geometry. Dynamically bendable flat mirrors, allowing focusing the beam at various planes down to sample position, collimating the beam, or no focusing, independently in vertical and horizontal directions (bending radii 5-100 km). Si, Rh, and Pt stripes for harmonic rejection. |
Sample position | 42 m downstream of the source. |
Flux at sample position | 1013 - 10 14 ph/s using the hDCM, 1014 - 10 15 ph/s using the hDMM (not yet measured). |
Beam size at sample position (FWHM; vertical x horizontal) | Variable between 1x1 mm2 and 15x60 µm 2. Larger and smaller beam sizes will be possible using secondary optics, to be installed in the experimental station. |
