Wolf J, Sperl JI, Schaff F, Schuettler M, Yaroshenko A, Zanette I, Herzen J, Pfeiffer F (2015)
Publication Type: Journal article
Publication year: 2015
Book Volume: 6
Pages Range: 4812-4824
Article Number: 246902
Journal Issue: 12
DOI: 10.1364/BOE.6.004812
X-ray grating interferometry requires gratings with periods in the micrometer range and allows the acquisition of the dark-field contrast. The analyzer grating is designed to match the period of the interference pattern in order to translate it into a measurable intensity modulation. In this study, we explore the influence of a sample-induced mismatch between the interference pattern and the analyzer grating on the dark-field contrast. We propose a formula for the calculation of the signal due to a period mismatch and present estimations varying periods and detector pixel size. Furthermore, numerical simulations of the X-ray wave-front demonstrate that the wave-front curvature, described by the lens-term, e.g. behind a parabolic lens or edges of a sample can change the period of the interference pattern. Our results give a concrete explanation for the formation of a dark-field contrast from object edges and thus allow a better understanding of the dark-field signal obtained with a grating interferometer.
APA:
Wolf, J., Sperl, J.I., Schaff, F., Schuettler, M., Yaroshenko, A., Zanette, I.,... Pfeiffer, F. (2015). Lens-term-and edge-effect in X-ray grating interferometry. Biomedical Optics Express, 6(12), 4812-4824. https://doi.org/10.1364/BOE.6.004812
MLA:
Wolf, Johannes, et al. "Lens-term-and edge-effect in X-ray grating interferometry." Biomedical Optics Express 6.12 (2015): 4812-4824.
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