TIT# Extraction of domain structure information from small-angle X-ray patterns of bulk materials AUT# Stribeck, N.; SOU# J. Appl. Cryst. (2001), 34, 496-503 LOC# xv056 CLA# COM# APP# MAT# ABS# A method is presented, which permits to extract and visualise topological structure information contained in scattering patterns from small-angle scattering (SAS) without complex pretreatment. Multi-dimensional, noisy raw data can be processed. Such data are for instance accumulated in the field of materials research from short-time exposed in-situ SAXS experiments with synchrotron radiation. The result is a multi-dimensional intersect or chord distribution, which is defined as the Laplacian of the correlation function. Moreover, it is equivalent to the autocorrelation of the gradient of the electron density. The procedure is, in particular, adapted to the analysis of the nanoscale structure of samples with fibre symmetry, such as of polymer fibres or of strained elastomers. Multi-dimensional relations among morphological components become apparent in real space and help to elucidate the nature of the process governing formation and change of structure on the nanometre scale. Utilising digital signal processing tools, the algorithm is based on spatial frequency filtering of the raw data. According to it, the background to be subtracted from the small-angle scattering pattern is formed from its own low spatial frequencies. Noise may be removed by suppressing high spatial frequencies. In the frequency band in between, the domain structure information of the studied nanocomposite appears.