BM31
BM31 Swiss Norwegian beamlines
Beamline characteristics
The newly installed (2022) BM31 end-station is specialized in combining X-ray absorption spectroscopy (XAS), powder diffraction (XRD), and total-scattering (XRTS) and works together seamlessly with the optics. The optics and end-station can automatically switch between various configurations. This enables measurements of XAS, XRD, and XRTS datasets in a combined time-resolved manner on the same sample under the same experimental conditions.
A set of sample environments is available for temperature-dependent-, catalytic- and electrochemistry experiments as well as a gas distribution and analysis system.
Techniques
- X-ray absorption spectroscopy (XAS) - unfocused 4.9 - 45 keV
- X-ray diffraction (XRD) - focused, 48 keV
- X-ray total-scattering (XRTS) and pair distribution functions (PDF) - focused, 48 keV, Qmax 27 Å-1
- Resonant XRD, thin film XRD on unfocused beam - 15 - 45 keV
Optics
|
Element
|
Description
|
| Monochromator | Air-bearing liquid nitrogen double-crystal monochromator |
| Monochromator crystals | 2 Flat Si[111] pair, and 2 sagittal focusing second crystals |
| Spectral range | 4.8 - 45 keV for XAS (unfocused), ~40 and ~50keV focused for XRD & PDF |
| Intrinsic resolution (DE/E) | Si[111]: 1.4 x 10-4 |
| Spot size | up to 10mm H x 0.6mm V and focussed 50µm H x 300µm V |
Detectors
The following detectors can be automatically put into action during the execution of your experiment.
- 14 ion chambers on translation stages - 4 I0 (before sample), 6 I1 (after sample) and 4 I2 (after I1) chambers available, selected automatically based on the measurement energy - moving during experiment to match energy
- A Vortex SDD with XIA Falcon X fast digital multichannel analyzer electronics for fluorescence spectroscopy
- A PILATUS3 X CdTe 2M with x-, y- and z- translation and pitch rotation for XRD and PDF. Sample-to-detector distance 190 - 1160 mm, pitch rotation up to 15°.
Sample Environment
- Gas flow stage with furnace for catalytic experiments in capillaries. Tmax 900 °C. High heating rate (100 °C/min), and low axial gradient capillary furnace. Gas distribution system including 4 mass flow controllers, each with a switch valve, 2 back pressure regulators (sample and exhaust), and a mass spectrometer. MFCs, switch valves and BPRs controllable from Pylaus software to synchronise with measurements.
- Static-gas pressure using a rig with turbo vacuum pump and gas dosing.
- Electrochemistry experiments can be performed with a BioLogic 16-channel potentiostat.
- Oxford Cryosystems Cryostream for 100 - 500 K (liquid N2).
- IUCR goniometer mount with goniometer heads for capillary measurements (XRD, PDF, XAS).
- Capillary rack with a fast x-, y-, z- stage for running multiple ex-situ samples in (XRD, PDF, XAS).
- Pellet grid for multiple ex-situ pellets (XAS).
High-Resolution Powder Diffraction (decommissioned)
NB. The old high-resolution diffractometer is unavailable, and likely not to be recommissioned unless there are a significant number of requests.
For users: please add the following to your acknowledgments:
The BM31 setup was funded by the Swiss National Science Foundation (grant 206021_189629) and the Research Council of Norway (grant 350506).





