Iterative and accurate determination of small angle X-ray scattering background

X-ray scattering is widely used in material structural characterizations. The weak scattering nature, however, makes it susceptible to background noise and can consequently render the final results unreliable. In this paper, we report an iterative method to determine X-ray scattering background and demonstrate its feasibility by small angle X-ray scattering on gold nanoparticles. This method solely relies on the correct structural modeling of the sample to separate scattering signal from background in data fitting processes, which allows them to be immune from experimental uncertainties. The importance of accurate determination of the scaling factor for background subtraction is also illustrated.