High-resolution high-efficiency X-ray imaging system based on the in-line Bragg magnifier and the Medipix detector

Vagovič, Patrik; Korytár, D.; Cecilia, A.; Hamann, Elias; Sveda, L.; Pelliccia, Daniele; Härtwig, J.; Zápražný, Zdenko; Oberta, P.; Dolbnya, Igor P.; Shawney, Kawal; Fleschig, Uwe; Fiederle, M.; Baumbach, Tilo

doi:10.1107/s0909049512044366

Cited by 23 publications

(19 citation statements)

References 24 publications

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“…Four pieces of highly asymmetric germanium crystal imaging monochromators built in a Vchannel configuration were prepared by planar technology and successfully applied for high-resolution holographic imaging using synchrotron radiation sources. 15,16 One disadvantage of such a system is the finite distance between crystals magnifying in the horizontal and vertical directions which causes the effective propagation distances between the horizontal and the vertical directions to be different. 16 This problem can be solved by further development of monolithic V-shaped 17 or Z-shaped 18 monochromators, for which we are able to set the horizontal and the vertical diffractions as close together as possible while preserving the inline configuration.…”

Section: Introductionmentioning

confidence: 99%

Calculations and surface quality measurements of high-asymmetry angle x-ray crystal monochromators for advanced x-ray imaging and metrological applications

et al. 2015

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Abstract. We present the numerical optimization and the technological development progress of x-ray optics based on asymmetric germanium crystals. We show the results of several basic calculations of diffraction properties of germanium x-ray crystal monochromators and of an analyzer-based imaging method for various asymmetry factors using an x-ray energy range from 8 to 20 keV. The important parameter of highly asymmetric monochromators as image magnifiers or compressors is the crystal surface quality. We have applied several crystal surface finishing methods, including advanced nanomachining using single-point diamond turning (SPDT), conventional mechanical lapping, chemical polishing, and chemomechanical polishing, and we have evaluated these methods by means of atomic force microscopy, diffractometry, reciprocal space mapping, and others. Our goal is to exclude the chemical etching methods as the final processing technique because it causes surface undulations. The aim is to implement very precise deterministic methods with a control of surface roughness down to 0.1 nm. The smallest roughness (∼0.3 nm), best planarity, and absence of the subsurface damage were observed for the sample which was machined using an SPDT with a feed rate of 1 mm∕min and was consequently polished using a fine polishing 15-min process with a solution containing SiO 2 nanoparticles (20 nm).

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Section: Introductionmentioning

confidence: 99%

Calculations and surface quality measurements of high-asymmetry angle x-ray crystal monochromators for advanced x-ray imaging and metrological applications

et al. 2015

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“…A much wider range of magnification factor will be realized at third-generation synchrotron radiation facilities where submicrometer resolutions have already been achieved with the conventional fixed magnification x-ray Bragg optics using PILATUS [1] and Medipix [6]. We expect that the performance of our variable-magnification x-ray Bragg optics will be maximized at linac-based x-ray sources such as x-ray free-electron lasers (XFELs) [7] and energy recovery linacs (ERLs) [8], which can produce diffraction-limited x-rays in both the horizontal and vertical directions.…”

Section: -3mentioning

confidence: 99%

Development and application of variable-magnification x-ray Bragg optics

Hirano¹,

Yamashita

Takahashi³

et al. 2016

AIP Conference Proceedings

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“…with a FReLoN camera and a two-dimensional Medipix silicon-based camera working in single-photon counting mode was studied by Vagovič et al (2011Vagovič et al ( , 2012Vagovič et al ( , 2013 with several test structures (Siemens star, Cu grids of different openings and biological objects) with the aim of exploring the imaging possibilities in absorption and phase-contrast modes. Fig.…”

Section: X-ray Beam Expansion As Two-dimensional Image Magnificationmentioning

confidence: 99%

Potential use of V-channel Ge(220) monochromators in X-ray metrology and imaging

et al. 2013

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While channel-cut crystals, in which the diffracting surfaces in an asymmetric cut are kept parallel, can provide beam collimation and spectral beam shaping, they can in addition provide beam compression or expansion if the cut is V-shaped. The compression/expansion ratio depends in this case on the total asymmetry factor. If the Ge(220) diffraction planes and a total asymmetry factor in excess of 10 are used, the rocking curves of two diffractors will have a sufficient overlap only if the second diffractor is tuned slightly with respect to the first one. This study compares and analyses several ways of overcoming this mismatch, which is due to refraction, when the Cu K 1 beam is compressed 21-fold in a V21 monochromator. A more than sixfold intensity increase was obtained if the matching was improved either by a compositional variation or by a thermal deformation. This provided an intensity gain compared with the use of a simple slit in a symmetrical channel-cut monochromator. The first attempt to overcome the mismatch by introducing different types of X-ray prisms for the required beam deflection is described as well. The performance of the V-shaped monochromators is demonstrated in two applications. A narrow collimated monochromatic beam obtained in the beam compressing mode was used for high-resolution grazing-incidence small-angle X-ray scattering measurements of a silicon sample with corrupted surface. In addition, a two-dimensional Bragg magnifier, based on two crossed V15 channel monochromators in beam expansion mode and tuned by means of unequal asymmetries, was successfully applied to high-resolution imaging of test structures in combination with a Medipix detector.

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High-resolution high-efficiency X-ray imaging system based on the in-line Bragg magnifier and the Medipix detector

Cited by 23 publications

References 24 publications

Calculations and surface quality measurements of high-asymmetry angle x-ray crystal monochromators for advanced x-ray imaging and metrological applications

Calculations and surface quality measurements of high-asymmetry angle x-ray crystal monochromators for advanced x-ray imaging and metrological applications

Development and application of variable-magnification x-ray Bragg optics

Potential use of V-channel Ge(220) monochromators in X-ray metrology and imaging

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