Optimization of sample thickness for small angle X-ray scattering (SAXS)

Abstract In small angle X-ray scattering (SAXS) experiments, there exists an optimal sample thickness to obtain measurements with the maximum signal-to-noise ratio and best statistics. In practice, the sample thickness may deviate from the optimal value due to certain conditions. For thick samples, smearing may appear for the scattering data and an equivalent sample position to compute the scattering vector. Calculations show that the sample thickness has a similar effect on SAXS for monodisperse and polydisperse systems. Qualitative and quantitative analysis has been performed to determine the deviation of equivalent sample position from the irradiated sample center.