Integration procedure for the quantitative analysis of dispersive anomalous diffraction

The development of the energy/angular dispersive diffraction setup, which c an be used for anomalous diffraction, allows the collection of diffracted i ntensities around an absorption edge, either over a continuous energy range [for DAFS (diffraction anomalous fine structure) studies], or at discrete energies [for simultaneous MAD (multiwavelength anomalous diffraction) stud ies]. Used with a large two-dimensional detector and an oscillating single crystal, this setup allows simultaneous collection of many reflections for a given energy range. An integration procedure has been developed along wit h a program, DAD (dispersive anomalous diffraction), for the collection and analysis of the raw images, to yield finally data in the form I(h, k, l, l ambda) for all reflections. Wavelength calibration and intensity correction s are made during the integration process, and parameters that may be neede d in later stages of the analysis are extracted and referenced within the i ntegrated data. A general procedure to calculate the positions of diffracte d reflections, for a monochromatic oscillation scan with a two-dimensional detector, when the incident beam is not perpendicular to the oscillation ax is, is also described.