Quantitative tomographic X-ray profiling of non-Bragg diffracting materials using phase retrieval X-ray diffractometry

Phase retrieval X-ray diffraction was used to profile the complex refractive index of a slice through an acetate filament sample with a square cross-section. High angular resolution X-ray Fraunhofer diffraction patterns and a logarithmic dispersion relation phase-retrieval formalism were used to recover the projection profile of the sample for each of several sample orientations. The tomographic reconstruction of the slice from these projections closely reproduced the refractive index, geometrical shape and size of the acetate filament, using only limited a priori knowledge of the sample.