Treatment of asymmetric SANS data

Small‐angle neutron scattering (SANS) is a useful technique for investigating the anisotropy of density fluctuations when these have single orientation direction. The commonly used method for treating asymmetric SANS data is to analyze sectors of data parallel and perpendicular to the orientation axis. Other methods based on the use of all the available two‐dimensional (2D) data are discussed. These consist in least‐squares fitting of the 2D data to models that include nonuniform deformations of the sample. An inverse 2D Fourier transform of the raw data has also been used to obtain an asymmetric pair correlation function. A hot stretched partially deuterated homopolymer and a stretched microphase segregated rubbery random copolymer system are used as examples of anisotropic scatterers.