Fabrication of diffraction gratings for hard X-ray phase contrast imaging

Endstation for ultrafast magnetic scattering experiments at the free-electron laser in Hamburg Rev. Sci. Instrum. 84, 013906 (2013) Impact system for ultrafast synchrotron experiments Rev. Sci. Instrum. 84, 013904 (2013) A digital miniature x-ray tube with a high-density triode carbon nanotube field emitter Appl. Phys. Lett. 102, 023504 (2013) Active diffraction gratings: Development and tests Rev. Sci. Instrum. 83, 123106 (2012) Orientation-selective X-ray dark field imaging of ordered systems J. Appl. Phys. 112, 114903 (2012) Additional information on Rev. Sci. Instrum. X-ray phase-contrast radiography and tomography enable to increase contrast for weakly absorbing materials. Recently, x-ray grating interferometers were developed that extend the possibility of phasecontrast imaging from highly brilliant radiation sources like third-generation synchrotron sources to non-coherent conventional x-ray tube sources. Here, we present the first installation of a three grating x-ray interferometer at a low-coherence wiggler source at the beamline W2 (HARWI II) operated by the Helmholtz-Zentrum Geesthacht at the second-generation synchrotron storage ring DORIS (DESY, Hamburg, Germany). Using this type of the wiggler insertion device with a millimeter-sized source allows monochromatic phase-contrast imaging of centimeter sized objects with high photon flux. Thus, biological and materials-science imaging applications can highly profit from this imaging modality. The specially designed grating interferometer currently works in the photon energy range from 22 to 30 keV, and the range will be increased by using adapted x-ray optical gratings. Our results of an energy-dependent visibility measurement in comparison to corresponding simulations demonstrate the performance of the new setup.

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“…25 The analyzer grating is manufactured by KIT using the LIGA process. 26 The periods and the depths of the gratings are listed in Table II.…”

Section: Grating Interferometer Geometrymentioning

confidence: 99%

X-ray grating interferometer for materials-science imaging at a low-coherent wiggler source

Herzen

Donath²,

Beckmann³

et al. 2011

Review of Scientific Instruments

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“…The source-to-G1 distance was 25 m and the distance between G1 and G2 was 0.12 m, corresponding to the third fractional Talbot distance of the phase grating. The phase grating G1 (π shifting, period p 1 = 3.98 µm) and the absorption grating G2 (p 2 = 2.00 µm) were made of silicon and silicon filled with electroplated gold respectively [16]. The x-ray camera consisted of a luminescent screen (100 µm YAG:Ce) lenscoupled (1:1 magnification, f-number 2.5, 150 mm focal length) to a CCD camera (PCO2000).…”

Section: Grating Interferometer and Experimental Setupmentioning

confidence: 99%

A tilted grating interferometer for full vector field differential x-ray phase contrast tomography

et al. 2011

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We report on a setup for differential x-ray phase-contrast imaging and tomography, that measures the full 2D phase-gradient information. The setup uses a simple one-dimensional x-ray grating interferometer, in which the grating structures of the interferometer are oriented at a tilt angle with respect to the sample rotation axis. In such a configuration, the differential phase images from opposing tomography projections can be combined to yield both components of the gradient vector. We show how the refractive index distribution as well as its x, y, and z gradient components can be reconstructed directly from the recorded projection data. The method can equally well be applied at conventional x-ray tube sources, to analyzer based x-ray imaging or neutron imaging. It is demonstrated with measurements of an x-ray phantom and a rat brain using synchrotron radiation. Abstract:We report on a setup for differential x-ray phase-contrast imaging and tomography, that measures the full 2D phase-gradient information.The setup uses a simple one-dimensional x-ray grating interferometer, in which the grating structures of the interferometer are oriented at a tilt angle with respect to the sample rotation axis. In such a configuration, the differential phase images from opposing tomography projections can be combined to yield both components of the gradient vector. We show how the refractive index distribution as well as its x, y, and z gradient components can be reconstructed directly from the recorded projection data. The method can equally well be applied at conventional x-ray tube sources, to analyzer based x-ray imaging or neutron imaging. It is demonstrated with measurements of an x-ray phantom and a rat brain using synchrotron radiation. Pai, "Single-shot x-ray differential phase-contrast and diffraction imaging using two-dimensional transmission gratings," Opt. Lett. 35, 1932Lett. 35, -1934Lett. 35, (2010. 13. H. Itoh, K. Nagai, G. Sato, K. Yamaguchi, T. Nakamura, T. Kondoh, C. Ouchi, T. Teshima, Y. Setomoto, and T. Den, "Two-dimensional grating-based X-ray phase-contrast imaging using Fourier transform phase retrieval," Opt. , 189-195 (2007). 21. The out-of-plane component cancels out because the phase integration, which is implicit in the modified reconstruction kernel, is always performed along the same direction in the camera coordinate system. Considering for instance an integral from left to right through the PMMA cylinder at the bottom of Fig. 2(d), the signal at its left edge is ∂ t Φ + ∂ z Φ where the signal in the tomographic rotation plane is ∂ t Φ > 0 and the out-of-plane signal ∂ z Φ < 0. Integrating through the same edge of the sample in Fig. 2(e), the out-of-plane signal has changed sign ∂ z Φ > 0, while the in-plane signal has again the same sign as before ∂ t Φ > 0. Reconstructing a slice using filtered back projection over a full sample rotation of 2π, each projection pair corresponds to a single line in twodimensional Fourier space. The out of plane component cancels out since it is o...

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“…19 The common fabrication procedure for these masks consists of a photolithography process followed by electroplating where heavy elements such as gold are usually used. 20 A number of techniques have been proposed to fabricate x-ray absorption gratings/masks as well as increase their performance, most of which were through the Lithography, Electroplating, and Molding (LIGA) process. [21][22][23][24] They have mainly attempted to increase the height to pitch ratio (aspect ratio) or field of view of gratings but realizing both goals at the same time has posed severe difficulties.…”

Section: Introductionmentioning

confidence: 99%

Edge-illumination x-ray phase contrast imaging with Pt-based metallic glass masks

Saghamanesh

Aghamiri

Olivo

et al. 2017

Review of Scientific Instruments

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Edge-illumination x-ray phase contrast imaging (EI XPCI) is a non-interferometric phase-sensitive method where two absorption masks are employed. These masks are fabricated through a photolithography process followed by electroplating which is challenging in terms of yield as well as time-and cost-effectiveness. We report on the first implementation of EI XPCI with Pt-based metallic glass masks fabricated by an imprinting method. The new tested alloy exhibits good characteristics including high workability beside high x-ray attenuation. The fabrication process is easy and cheap, and can produce large-size masks for high x-ray energies within minutes. Imaging experiments show a good quality phase image, which confirms the potential of these masks to make the EI XPCI technique widely available and affordable. Published by AIP Publishing. [http://dx

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Fabrication of diffraction gratings for hard X-ray phase contrast imaging

Cited by 212 publications

References 6 publications

X-ray grating interferometer for materials-science imaging at a low-coherent wiggler source

X-ray grating interferometer for materials-science imaging at a low-coherent wiggler source

A tilted grating interferometer for full vector field differential x-ray phase contrast tomography

Edge-illumination x-ray phase contrast imaging with Pt-based metallic glass masks

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