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Gauging low-dose X-ray phase-contrast imaging at a single and large propagation distance

Hofmann, R.; Schober, A.; Hahn, S.; Moosmann, J.; Kashef, J.; Hertel, M.; Weinhardt, V.; Hänschke, D.; Helfen, L.; Salazar, I.A.S.; Guigay, J.-P.; Xiao, X.; Baumbach, T.

Abstract (englisch):
The interactions of a beam of hard and spatio-temporally coherent X-rays with a soft-matter sample primarily induce a transverse distribution of exit phase variations δϕ (retardations or advancements in pieces of the wave front exiting the object compared to the incoming wave front) whose free-space propagation over a distance z gives rise to intensity contrast gz. For single-distance image detection and |δϕ| ≪ 1 all-order-in-z phase-intensity contrast transfer is linear in δϕ. Here we show that ideal coherence implies a decay of the (shot-)noise-to-signal ratio in gz and of the associated phase noise as z−1/2 and z−1, respectively. Limits on X-ray dose thus favor large values of z. We discuss how a phase-scaling symmetry, exact in the limit δϕ → 0 and dynamically unbroken up to |δϕ| ∼ 1, suggests a filtering of gz in Fourier space, preserving non-iterative quasi-linear phase retrieval for phase variations up to order unity if induced by multi-scale objects inducing phase variations δϕ of a broad spatial frequency spectrum. Such an approach continues to be applicable under an assumed phase-attenuation duality. Using synchrotron radi ... mehr


Zugehörige Institution(en) am KIT Laboratorium für Applikationen der Synchrotronstrahlung (LAS)
Institut für Photonenforschung und Synchrotronstrahlung (IPS)
Publikationstyp Zeitschriftenaufsatz
Jahr 2016
Sprache Englisch
Identifikator DOI: 10.1364/OE.24.004331
ISSN: 1094-4087
URN: urn:nbn:de:swb:90-539736
KITopen ID: 1000053973
HGF-Programm 56.03.30; LK 01
Erschienen in Optics express
Band 24
Heft 4
Seiten 4331-4348
Bemerkung zur Veröffentlichung Gefördert durch den KIT-Publikationsfonds
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