X-ray phase-contrast imaging with engineered porous materials over 50 keV

Wang, H.; Cai, Biao; Pankhurst, Matthew J.; Zhou, Tao; Kashyap, Yogesh; Atwood, Robert C.; Gall, Nolwenn Le; Lee, Peter; Drakopoulos, Michael; Sawhney, Kawal

doi:10.1107/s1600577518005623

Cited by 6 publications

(3 citation statements)

References 32 publications

(14 reference statements)

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“…Speckle phenomena are widely used for metrology and other experiments within the visible optics community (Goodman, 2007(Goodman, , 2015. In the last decade, speckle-based techniques have been extended to the X-ray region, both for X-ray imaging research (Be ´rujon, Ziegler, Cerbino & Peverini, 2012;Berujon, Wang & Sawhney, 2012;Morgan et al, 2012;Zanette et al, 2014;Berujon & Ziegler, 2015Wang et al, , 2018Wang, Kashyap & Sawhney, 2015a,b;Zhou et al, 2015;Wang, Kashyap & Sawhney, 2016a,b;Zdora et al, 2017) and for at-wavelength measurement of X-ray optics (Be ´rujon, Wang, Ziegler & Sawhney, 2012;Berujon et al, 2014Berujon et al, , 2020aWang, Kashyap & Sawhney, 2015a, Zhou, Wang, Fox et al, 2018. A review of the use of speckle-based techniques in X-ray imaging has been published (Zdora, 2018).…”

Section: Principles Of the 2d Wavefront Slope Error Measurementmentioning

confidence: 99%

Two-dimensional speckle technique for slope error measurements of weakly focusing reflective X-ray optics

Hu¹,

Wang²,

Fox³

et al. 2022

J Synchrotron Radiat

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Speckle-based at-wavelength metrology techniques now play an important role in X-ray wavefront measurements. However, for reflective X-ray optics, the majority of existing speckle-based methods fail to provide reliable 2D information about the optical surface being characterized. Compared with the 1D information typically output from speckled-based methods, a 2D map is more informative for understanding the overall quality of the optic being tested. In this paper, we propose a method for in situ 2D absolute metrology of weakly focusing X-ray mirrors. Importantly, the angular misalignment of the mirror can be easily corrected with the proposed 2D processing procedure. We hope the speckle pattern data processing method presented here will help to extend this technique to wider applications in the synchrotron radiation and X-ray free-electron laser communities.

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Section: Principles Of the 2d Wavefront Slope Error Measurementmentioning

confidence: 99%

Two-dimensional speckle technique for slope error measurements of weakly focusing reflective X-ray optics

Hu¹,

Wang²,

Fox³

et al. 2022

J Synchrotron Radiat

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“…The number M of modulator positions should be chosen as small as possible in order to further reduce the data acquisition time for the phase CT. For the present case, the diameter of steel wool is about 25 µm, and the averaged speckle size generated by the steel wool is about ς ≅ 80 µm. To further reduce the speckle size and the scanning range, the steel wool can be potentially replaced with porous engineering materials 23 tailored to produce suitable speckle. One speckle intensity curve as a function of R is shown in the inset of Fig.…”

Section: Introductionmentioning

confidence: 99%

High-energy, high-resolution, fly-scan X-ray phase tomography

Wang

Atwood

Pankhurst

et al. 2019

Sci Rep

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High energy X-ray phase contrast tomography is tremendously beneficial to the study of thick and dense materials with poor attenuation contrast. Recently, the X-ray speckle-based imaging technique has attracted widespread interest because multimodal contrast images can now be retrieved simultaneously using an inexpensive wavefront modulator and a less stringent experimental setup. However, it is time-consuming to perform high resolution phase tomography with the conventional step-scan mode because the accumulated time overhead severely limits the speed of data acquisition for each projection. Although phase information can be extracted from a single speckle image, the spatial resolution is deteriorated due to the use of a large correlation window to track the speckle displacement. Here we report a fast data acquisition strategy utilising a fly-scan mode for near field X-ray speckle-based phase tomography. Compared to the existing step-scan scheme, the data acquisition time can be significantly reduced by more than one order of magnitude without compromising spatial resolution. Furthermore, we have extended the proposed speckle-based fly-scan phase tomography into the previously challenging high X-ray energy region (120 keV). This development opens up opportunities for a wide range of applications where exposure time and radiation dose are critical.

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“…In contrast, X-ray tomography in principle allows the dynamics of solidification and other phase transformations to be resolved in 3D. However the analysis of the data is more complicated and cumbersome and while qualitative imaging by tomography can be highly instructive, there are relatively few reports of quantified chemical segregation studies by X-ray tomography [30], [31]. Nelson et al developed a method to extract 3D solute distributions from X-ray tomographs of a solidifying Al-15wt%Cu alloy during directional solidification at 0.05 Ks -1 , both parallel and anti-parallel to gravity [31].…”

mentioning

confidence: 99%