SIMULATION OF SMALL-ANGLE X-RAY-SCATTERING FROM SINGLE-PARTICLE SYSTEMS

Elastic small-angle scattering is sensitive to morphology on the collo idal length scale. In order to make better use of this technique to pr obe microstructure, a computer program is being developed that will ca lculate scattering patterns for objects whose shapes and arrangements in space are arbitrary. This program utilizes X-ray diffraction first principles and its only requirement is that the scattering object is c entrosymmetric. The simulated data can then be used to extract morphol ogical information from multiphase anisotropic materials, such as poly mers, polymer composites and metal alloys. This paper demonstrates the accuracy of this modeling technique for three single-particle morphol ogies. These simulations are compared to their analytical solution cou nterparts to show the level of accuracy that can be obtained as a func tion of simulation time or number of simulated scattering points. This method can be easily adapted to simulate small-angle scattering for s ingle particles whose orientations or geometries make analytical solut ion extremely difficult or impossible. This is demonstrated with simul ations of scattering from a nonideally oriented cylinder, from an elon gated hexagon and from a bundle of cylinders.