Two-dimensional reconstruction of small angle scattering patterns from rocking curves

The reconstruction of two-dimensional functions from their line integrals over straight lines can be applied to the problem of scanning a two-dimensional scattering pattern with the analyzer crystal of a double crystal diffractometer. This becomes important, if structures exceed certain dimensions, where conventional small angle scattering facilities cannot image them as contour plots. It is demonstrated that especially in the case of a limited range of scanning angle (0-90 degrees) the standard filtered back projection (FBP) technique does not deliver satisfactory results. A modified algebraic reconstruction technique, however, supplies much better reconstruction than FBP. (C) 1998 Elsevier Science B.V. All rights reserved.