SAXS/WAXS

For a presentation of the SAXS basic theory, techniques and applications, you can download the book Small Angle X-ray Scattering (O. Glatter and O. Kratky Eds., Academic Press, 1982) from http://physchem.kfunigraz.ac.at/sm/ (Scattering Methods at the Chemistry Department, University of Graz).

For a more biologically oriented introduction one can download Structure Analysis by Small-Angle X-Ray and Neutron Scattering (L. A. Feigin and D. I. Svergun, Plenum Press / Springer, 1987) from http://www.embl-hamburg.de/biosaxs/publications.html

From a practical point of view, you might want to take a look at the Beamline Manuals page. One can find there a short User's survival manual, the full manual of the data acquisition and reduction software for collecting and pre-processing SAXS and/or WAXS data for both static and time-resolved measurements on beamline BM26B, as well as a list of basic Unix commands.

Last but not least, the Data Reduction and Analysis page provides the response of the detector in use, together with links to data reduction and analysis software.

The station

Photo: Daniel Michon, ARTECHNIQUE

With the SAXS/WAXS station one can simultaneously obtain wide- and small-angle scattering patterns. This photograph shows the SAXS station. Here the SAXS pattern is collected by a 1D quadrant but area detectors are also available. The WAXS pattern was initially detected by a curved linear detector, now replaced by a 2D device (cf. WAXS detectors).
The low angle resolution of the SAXS station is dependent on the X-ray wave length and the sample-to-detector distance.

SAXS detectors

Currently one can use as SAXS detector either a Pilatus 1M detector or a FReLoN 2k CCD camera. If needed, namely in case of malfunction of these two devices, the Multiwire Proportional Counters are still available.

• The Pilatus 1M detector is described in C. Broennimann et al., Journal of Synchrotron Radiation 13 (2006), 120-130. Its main characteristics are given below, together with those of the Pilatus 300K-W.
  
• A basic presentation of the FReLoN camera is given here; technical data sheet is available here.
• A description of how the gas-filled wire chamber detectors operate can be found in A. Gabriel and F. Dauvergne, The localisation method used at EMBL, Nuclear Instruments and Methods 201 (1982), 223-224.
• The operating principle of the 1D quadrant detector is explained here.
• An abstract about the position sensitive detector technology, data reduction, and count rates can be downloaded here (as pdf).

Pilatus 1M detector

Pilatus (by Dectris) is a state-of-the-art detector family with remarkable characteristics. The Pilatus 1M has been installed on the beamline and is operational from January 2011.

General characteristics

• fast, ultra low noise, very high dynamic range
• operates in single-photon counting mode
• based on CMOS hybrid-pixel technology
• high frame rate
• operates at room temperature

FReLoN 2k camera

The FReLoN 2000 (the acronym stands for Fast-Readout, Low-Noise) is a CCD camera developed by the ESRF Instrument Support Group.

Technical data sheet is available here.

Wire chamber detectors

Characteristics

Detector calibration

• Silver Behenate Peak Positions
• Rat Tail Positions 

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WAXS detectors

WAXS data can currently be acquired using a Pilatus 300K-W detector from Dectris (see details below) or a CCD-based X-ray digital camera: either the FReLoN 2000 (2048×2048 pixels), or a VHR (2657×3955 pixels) from Photonic Science.

  This system is the very first Pilatus at the ESRF. It arrived at DUBBLE at mid April 2009.

Characteristics

• air-cooled => simple in operation and handling
• PC with Linux OS (Suse 10.3) + a data acquisition and analysis software (TVX)

Technical specifications of the two Pilatus detectors

For those who might miss the old MSGC (MicroStrip Gas Chamber) detector, some information about it is still available here.

Detector calibration

• HDPE Peak Positions
• NBS Silicon Powder

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