Visibility in differential phase-contrast imaging with partial coherence source

This paper gives theoretical analysis of visibility of fringes,which is influenced by distances, temporal and spatial coherenceof source, in hard x-ray differential phase-contrast imagingwith microfocus x-ray source. According to the character oflongitudinal periodicity of the interferogram, the setup isinsensitive to mechanical drift and vibrations. The effect oftemporal coherence of x-ray source is investigated and itsrelated bandwidth is derived. Based on the theory of partiallycoherent light, it shows that the requirement for the spatialcoherence of x-ray source is not strict and can be met by thegeneral microfocus x-ray tube for x-ray differentialphase-contrast imaging.