Wave optical simulations of x-ray nano-focusing optics

Advancing the Characterization of Neuronal Cyto-Architecture by X-ray Phase-Contrast Tomography

“…Spatial coherence can be defined as 𝜉 ⊥ = 𝜆 2⋅𝑠/𝑧 01 [1]: Due to the low divergence of synchrotron radiation, coherence-beamlines have a source spot 𝑠 much smaller than its distance to the endstation 𝑧 01 (again, for P10 as an example of a primary source at the GINIX-endstation in parallel-beam (PB) geometry: 𝑠 = 39 µm (h) or 𝑠 = 250 µm (v) [134], 𝑧 01 ≈ 86.1 m, 𝐸 = 12 keV; or with a secondary source (waveguide, WG) in cone-beam (CB) geometry: 𝑠 = 30 nm, 𝑧 01 = 125 mm, 𝐸 = 8 keV [171]). They exhibit high spatial coherence 𝜉 ⊥ = 114 µm (h, PB) or 𝜉 ⊥ = 323 µm (CB), respectively, which is 100-1000 times the sampling length, allowing for deep-holographic imaging at 𝐹 𝑟 ≈ 10 −4 .…”

Cone-beam x-ray phase-contrast tomography for the observation of single cells in whole organs

“…The spatial coherence of an x-ray beam can be increased similarly by using, e.g., a small source size and/or large distance to the source. X-ray waveguides, which are of particular relevance for the present work, are also able to increase the spatial coherence by mode filtering [127], i.e., only coherent modes survive the propagation in a wave guiding channel.…”

“…The use of x-ray waveguides to filter the radiation has many advantages, i.e., the radiation can be focused to spots below 10 nm [92] and spatial coherence is increased [127]. Figure 4.9 shows two realization principles of 2D x-ray waveguides.…”

A dedicated endstation for waveguide-based x-ray imaging

“…The data was generated by a numerical calculation of the Fresnel-Kirchhoff diffraction integral. It is developed by Markus Osterhoff as a part of his dissertation at the Georg-August-Universität Göttingen [59].…”