Simulation of X-ray refraction information extraction using multiple image-collecting strategies

Abstract

With different strategies collecting images, the extraction results of refraction information using the diffraction-enhanced imaging (DEI), generalized diffraction-enhanced imaging (G-DEI) or multiple-image radiography (MIR) algorithm of analyzer-based imaging technique are greatly different from each other. Compared with the conventional strategy in which the images are acquired at the waist positions of rocking curve (RC), the one with the positions closer to the central axis of RC can obtain more accurate refraction information for the DEI algorithm. For the G-DEI algorithm taking three images, if the positions, where images are obtained, are symmetrical with respect to the central axis of RC, the extraction result of refraction information is better when the positions are asymmetrical. Besides, by comparison with the strategy in which the images are acquired at the waist or toe positions, the one with the positions closer to central axis of RC can obtain better result. If the angle interval of neighbor positions is larger than the full-width at half-maximum (FWHM) of RC, the extraction result of the MIR algorithm is bad. When the angle interval is smaller than the FWHM, and the value of angle range of all positions collecting images is close to the maximum theoretical value of sample, the extraction result is very good. This study will be helpful for reasonably choosing the image-collecting strategies in experiment, and further understanding the extraction algorithms of refraction information.