The guiding principles of the design of the SWAXS setup are flexibility and ease of use. Since novel wood-based materials is a special focus of ForMAX, the WAXS detector must allow monitoring diffraction from cellulose fibrils/fibers in all directions of the scattering plane. Since many in-situ studies during material processing are foreseen, data acquisition times down to ms regime is needed. Specific equipment are listed below.

Detectors

ForMAX is equipped with two state-of-the-art hybrid pixel detectors: a Dectris EIGER2 X 4M SAXS detector and a custom-designed X-Spectrum Lambda 3M WAXS detector. The SAXS detector is placed on a motorized XYZ trolley inside the SAXS flight tube. The WAXS detector is mounted on an evacuated nose cone of the flight tube and the four modules of the WAXS detector have a “windmill” geometry with a hole in the center, to pass through the direct beam and the SAXS signal (see image below). It allows WAXS data collection at scattering angles 2θ=7-20 degrees, in all directions. See table below for details of the detectors.

DetectorEIGER2 X 4MLambda 3M "windmill"
UsageSAXSWAXS
Number of pixels4M3M
Sensor size (h x v)2068×2162 pixels4x512x1536 pixels
Pixel size (h x v)75×75 µm255×55 µm2
Maximum frame rate500 Hz1 kHz

Sample manipulation

ForMAX has the following sample stages for different SWAXS experiments:

  • SWAXS: A modular 5-axis stack of sample stages from Huber for general SWAXS experiment. From bottom to top:
    • 2-circle segment (pitch, roll), model 5203.30 (+/- 13 and +/- 12 degrees range for lower and upper axis, respectively)
    • 2-axis horizontal stage, model 5102.25 (+/- 25 mm translation range for each axis)
    • vertical stage, either model 5103.A20-40 (+/- 20 mm translation range) or 5103.A20-90 (+/- 45 mm translation range)
  • Scanning SWAXS imaging: Two additional stages (pitch, yaw) can be mounted on top of the SWAXS stack:
    • custom large-range pitch stage, model 5202.80 (+/- 45 degrees)
    • yaw stage, model 408
Custom Lambda 3M “windmill” WAXS detector.
Cellulose diffraction pattern, measured from a thin piece of oak at 12.9 keV.