Laboratory SAXS-facility at the Graz University of Technology

Source and Cameras

The lab-SAXS facility consists of a sealed tube X-ray generator (DebyeFlex3000, with three opening ports and shutters, to which three SAXSess cameras (A. Paar, Graz, Austria) are attached. Two of them are attached to the line-focus port, one to the point-focus port. All cameras can be operated at the same time and independently from each other. The sealed X-ray tube has a Cu-target emitting Cu-Kα-radiation (λ = 0.154 nm) and can be operated at a maximum power of 2000 Watt. Read more

Resolution (accessible range of scattering angles)

  • SAXS-mode: (1D or 2D-detector) with an angular range from 0-8 (corresponding to d-values from 100 to 1 nm).
  • SWAXS-mode: (SAXS: 1D or 2D, WAXS: 1D) with an additional WAXS range from 17.5 to 35 (corresponding to d-values from 0.5 to 0.25 nm).
  • Continuous SWAXS-mode: with an image plate, the entire angular range from 0-35 is covered.

The WAXS-tubus attachment can be mounted on each camera

X-ray detectors

  • 2D-Detector: CCD-detector (PI-SCX from Roper Scientific, Germany): 2084x2084 array with 24x24 m pixels. Active area: 5 x 5 cm.
  • 1D-Diode array detector: Mythen 1K (Dectris, Switzerland), 1280 pixels a 50 m. Active length: 6.4 cm.
  • Image Plate Reader System: Cyclone (Perkin Elmer) with Optiquant software. Image plates with dimensions SAXS: 65 x 60 mm and SWAXS: 65 x 200 mm respectively (pixel resolution 50 x 50 m) can be used.

Sample holders

  • Thermostatted sample holder stages (transmission mode): For individual measurements, most sample holders (as well as detectors) are interchangeable on the 3 cameras.
  • Peltier heating/cooling controlled sample holder block in the range from -30 to 120C (0.1 precision).
  • Resistance heater controlled sample holder block in the range from room temperature to 300C.

Liquid samples are usually filled into a quartz cuvette holder, which contains a reusable quartz capillary (1 mm diameter, 10 m wall thickness) with sealable screw-caps on both ends. Solid samples, powders or very viscous samples can be placed in a special paste-and powder holder in which the sample is sandwiched between two foils and sealed vacuum-tight. Both sample holders can be inserted into the two sample holder blocks for temperature control.

  • GI-SAXS sample stage (GISAXS-mode): GISAXS samples can be rotated in the X-axis (ω, normal to the X-ray beam) and rotated in the axis normal to the surface (ϕ). The maximum rotation angles are - 8 < ω< 5 and 0 < ϕ < 360. The minimum step sizes are 0.0005 in ω and in ϕ. The maximum sample dimensions are (length x width x thickness) 21 x 21 x 4 mm.

Software

  • SAXSquant (A. Paar, Graz, Austria) is used as the comprehensive control/data-acquisition/data-evaluation software for automated control of the camera system components, for automated measurements and for producing scattering patterns (2D) and curves (1D) from detector data. It is designed to perform raw-data processing (data normalization, background subtraction, q-scale calibration, desmearing).



Contact: Heinz Amenitsch
Tel: +43 (316) 873 - 32145