scholarly journals Hard X-ray polarizer to enable simultaneous three-dimensional nanoscale imaging of magnetic structure and lattice strain

2016 ◽  
Vol 23 (5) ◽  
pp. 1210-1215 ◽  
Author(s):  
Jonathan Logan ◽  
Ross Harder ◽  
Luxi Li ◽  
Daniel Haskel ◽  
Pice Chen ◽  
...  
Keyword(s):  
Magnetic Circular Dichroism ◽  
Three Dimensional ◽  
Control Sample ◽  
Magnetic Ordering ◽  
X Rays ◽  
Diffractive Imaging ◽  
X Ray ◽  
Coherent Diffractive Imaging ◽  
Diffraction Patterns ◽  
A New Technique

Recent progress in the development of dichroic Bragg coherent diffractive imaging, a new technique for simultaneous three-dimensional imaging of strain and magnetization at the nanoscale, is reported. This progress includes the installation of a diamond X-ray phase retarder at beamline 34-ID-C of the Advanced Photon Source. The performance of the phase retarder for tuning X-ray polarization is demonstrated with temperature-dependent X-ray magnetic circular dichroism measurements on a gadolinium foil in transmission and on a Gd5Si2Ge2crystal in diffraction geometry with a partially coherent, focused X-ray beam. Feasibility tests for dichroic Bragg coherent diffractive imaging are presented. These tests include (1) using conventional Bragg coherent diffractive imaging to determine whether the phase retarder introduces aberrations using a nonmagnetic gold nanocrystal as a control sample, and (2) collecting coherent diffraction patterns of a magnetic Gd5Si2Ge2nanocrystal with left- and right-circularly polarized X-rays. Future applications of dichroic Bragg coherent diffractive imaging for the correlation of strain and lattice defects with magnetic ordering and inhomogeneities are considered.

The Atomic Order in Guinier-Preston Zones of Aluminum-Silver Alloys

1963 ◽  
Vol 7 ◽  
pp. 1-13 ◽  
Author(s):  
Volkmar Gerold ◽  
Heinz Auer ◽  
Winfried Merz
Keyword(s):  
Room Temperature ◽  
Three Dimensional ◽  
Miscibility Gap ◽  
X Rays ◽  
Atomic Order ◽  
Zone Size ◽  
X Ray ◽  
Angle Scattering ◽  
Diffraction Patterns ◽  
Step Quenching

AbstractThe formation of the spherical Guinier—Preston zones in an aluminum-silver alloy is governed by a metastable miscibility gap, which consists of two different sections. The lower section occurs below 170°C (η state), the higher section up to 420°C (∊ state). The zones in the two sections differ in their silver concentration and in their atomic order. To prove the change in order, a combination of X-ray small-angle scattering and electric resistivity measurements was used. As the resistivity depends on the zone size and the atomic order, the change in order can be found when the zone size is known. This size was measured by the X-ray technique. To complete the results, X-rays ingle-crystal diffraction patterns with monochromatic radiation were taken at different stages. According to these patterns, three different states must be distinguished.The η′ state exists at room temperature after quenching from 550°C. The silver atoms prefer a layered arrangement in the zones, which is not very stable. It is destroyed after short annealings above 100°C. The η state is developed during annealing below 170°C. A three-dimensional atomic order is built up with increasing zone size, which results in a marked decrease in the resistivity. For the ∊ state (above 170°C), a nearly random atomic distribution exists. Step-quenching experiments prove that the ordered η state can also be developed at room temperature.

scholarly journals Design of a liquid cell toward three-dimensional imaging of unidirectionally-aligned particles in solution using X-ray free-electron lasers

2020 ◽  
Vol 22 (5) ◽  
pp. 2622-2628 ◽  
Author(s):  
Akihiro Suzuki ◽  
Takashi Kimura ◽  
Ying Yang ◽  
Yoshiya Niida ◽  
Akiko Nishioka ◽  
...  
Keyword(s):  
Free Electron ◽  
Three Dimensional ◽  
Free Electron Lasers ◽  
Diffractive Imaging ◽  
Three Dimensional Imaging ◽  
X Ray ◽  
Coherent Diffractive Imaging ◽  
Liquid Cell

A liquid cell was designed for coherent diffractive imaging measurements at high tilt angles and tested at SACLA.

Monochromatic X-ray microscopy in the water window with a compact laser system

1994 ◽  
Vol 52 ◽  
pp. 60-61
Author(s):  
M. Kado ◽  
M. Richardson ◽  
K. Gabel ◽  
F. Jin
Keyword(s):  
High Resolution ◽  
Laser System ◽  
Three Dimensional ◽  
X Rays ◽  
X Ray ◽  
Water Window ◽  
Laser Plasmas ◽  
A New Technique ◽  
Bright Source

It is a dream of biologist to observe the intact structure of a biological specimen at high resolution without any artifacts. The development of high resolution x-ray microscopy is a new technique well suited to this purpose. The advantages of x-ray microscopy are seen to be: (i) the contrast can be provided by its components, thereby avoiding possible artifacts caused by the staining and fixation of specimens; (ii) x-ray microscopy is capable of observing thicker specimens (up to a few (μm)than electron microscopy with less damage; (iii) the actual location of the element can be visualizedwhen the proper x-ray wavelength is chosen. (iv) three-dimensional observation may be possible with asingle exposure of x rays. X-ray contact microscopy is presendy the most suitable method by which to evaluate these advantages.It is generally accepted that the highest contrast in x-ray images of in-vitro biological specimens will be obtained with radiation have a wavelength in the so-called “water window”, (2.3-4.4 nm). Both laser plasmas and synchrotrons are bright source of radiation in this region.

Frontier methods in coherent X-ray diffraction for high-resolution structure determination

2016 ◽  
Vol 49 ◽  
Author(s):  
Marcus Gallagher-Jones ◽  
Jose A. Rodriguez ◽  
Jianwei Miao
Keyword(s):  
Structure Determination ◽  
X Rays ◽  
X Ray Diffraction ◽  
Diffractive Imaging ◽  
X Ray ◽  
Coherent Diffractive Imaging ◽  
X Ray Crystallography ◽  
Max Von Laue ◽  
Complex Protein ◽  
High Resolution Structure

AbstractIn 1912, Max von Laue and collaborators first observed diffraction spots from a millimeter-sized crystal of copper sulfate using an X-ray tube. Crystallography was born of this experiment, and since then, diffraction by both X-rays and electrons has revealed a myriad of inorganic and organic structures, including structures of complex protein assemblies. Advancements in X-ray sources have spurred a revolution in structure determination, facilitated by the development of new methods. This review explores some of the frontier methods that are shaping the future of X-ray diffraction, including coherent diffractive imaging, serial femtosecond X-ray crystallography and small-angle X-ray scattering. Collectively, these methods expand the current limits of structure determination in biological systems across multiple length and time scales.

scholarly journals Considerations for three-dimensional image reconstruction from experimental data in coherent diffractive imaging

IUCrJ ◽  
2018 ◽  
Vol 5 (5) ◽  
pp. 531-541 ◽  
Author(s):  
Ida V. Lundholm ◽  
Jonas A. Sellberg ◽  
Tomas Ekeberg ◽  
Max F. Hantke ◽  
Kenta Okamoto ◽  
...  
Keyword(s):  
Experimental Data ◽  
Phase Retrieval ◽  
Three Dimensional ◽  
Simulated Data ◽  
High Repetition Rate ◽  
Central Feature ◽  
Diffractive Imaging ◽  
X Ray ◽  
Background Removal ◽  
Diffraction Patterns

Diffraction before destruction using X-ray free-electron lasers (XFELs) has the potential to determine radiation-damage-free structures without the need for crystallization. This article presents the three-dimensional reconstruction of the Melbournevirus from single-particle X-ray diffraction patterns collected at the LINAC Coherent Light Source (LCLS) as well as reconstructions from simulated data exploring the consequences of different kinds of experimental sources of noise. The reconstruction from experimental data suffers from a strong artifact in the center of the particle. This could be reproduced with simulated data by adding experimental background to the diffraction patterns. In those simulations, the relative density of the artifact increases linearly with background strength. This suggests that the artifact originates from the Fourier transform of the relatively flat background, concentrating all power in a central feature of limited extent. We support these findings by significantly reducing the artifact through background removal before the phase-retrieval step. Large amounts of blurring in the diffraction patterns were also found to introduce diffuse artifacts, which could easily be mistaken as biologically relevant features. Other sources of noise such as sample heterogeneity and variation of pulse energy did not significantly degrade the quality of the reconstructions. Larger data volumes, made possible by the recent inauguration of high repetition-rate XFELs, allow for increased signal-to-background ratio and provide a way to minimize these artifacts. The anticipated development of three-dimensional Fourier-volume-assembly algorithms which are background aware is an alternative and complementary solution, which maximizes the use of data.

scholarly journals Polarimetric coherent diffraction imaging on cancer-associated fibroblasts and SARS-CoV-2 viruses

2021 ◽  
Author(s):  
Xiaowen Shi ◽  
Dmitry Karpov ◽  
Zach Barringer ◽  
Elijah Schold ◽  
Demba Sarr ◽  
...  
Keyword(s):  
High Resolution ◽  
Imaging Techniques ◽  
Complex Refractive Index ◽  
Cancer Associated Fibroblasts ◽  
X Rays ◽  
Label Free ◽  
Diffractive Imaging ◽  
Dynamical Interaction ◽  
X Ray ◽  
Coherent Diffractive Imaging

Abstract Simultaneously non-destructive, high resolution, and label-free imaging are of paramount importance for studies of complex biological systems, from viruses to cell cultures. Electron imaging techniques achieve extreme resolution but require slicing the sample to obtain volumetric information. On the other hand, X-rays’ high penetrative ability combined with cryogenic temperatures allows access to high resolution while preserving the sample’s structure. However, both X-ray and electron techniques do not currently allow label-free imaging with tissue specificity. Here, we combine a polarimetric approach with coherent diffractive imaging to reveal new ways to overcome this by mapping variations of anisotropy in the complex refractive index of cellular structures to differentiate between various tissues without chemical labeling. In this article, we demonstrate imaging of cancer-associated fibroblasts using birefringent coherent diffractive imaging with enhanced sensitivity to fibrous structures and their orientation as well as the possibility to differentiate the nucleus of the cell. We also propose a modeled soft X-ray experiment on the SARS-CoV-2 virus to address the possibility of leveraging the polarimetric birefringent contrast to spatially resolve the dynamical interaction of the virus with its host environment. We hope that our approach can open up avenues in the future to map and understand how SARS viruses bind with human epithelial cells.

Three-dimensional coherent diffractive imaging on non-periodic specimens at the ESRF beamline ID10

2014 ◽  
Vol 21 (3) ◽  
pp. 594-599 ◽  
Author(s):  
Y. Chushkin ◽  
F. Zontone ◽  
E. Lima ◽  
L. De Caro ◽  
P. Guardia ◽  
...  
Keyword(s):  
Synchrotron Radiation ◽  
Photon Energy ◽  
Three Dimensional ◽  
European Synchrotron Radiation Facility ◽  
X Rays ◽  
Diffractive Imaging ◽  
Three Dimensional Imaging ◽  
Coherent Diffractive Imaging ◽  
Magnetic Nanorods

The progress of tomographic coherent diffractive imaging with hard X-rays at the ID10 beamline of the European Synchrotron Radiation Facility is presented. The performance of the instrument is demonstrated by imaging a cluster of Fe2P magnetic nanorods at 59 nm 3D resolution by phasing a diffraction volume measured at 8 keV photon energy. The result obtained shows progress in three-dimensional imaging of non-crystalline samples in air with hard X-rays.

scholarly journals A Monte Carlo ray-tracing simulation of coherent X-ray diffractive imaging

2020 ◽  
Vol 27 (1) ◽  
pp. 134-145 ◽  
Author(s):  
Giovanni Fevola ◽  
Erik Bergbäck Knudsen ◽  
Tiago Ramos ◽  
Dina Carbone ◽  
Jens Wenzel Andreasen
Keyword(s):  
Ray Tracing ◽  
Phase Retrieval ◽  
Computational Effort ◽  
Retrieval Algorithm ◽  
Theoretical Formulation ◽  
Thin Sample ◽  
Diffractive Imaging ◽  
X Ray ◽  
Coherent Diffractive Imaging ◽  
Diffraction Patterns

Coherent diffractive imaging (CDI) experiments are adequately simulated assuming the thin sample approximation and using a Fresnel or Fraunhofer wavefront propagator to obtain the diffraction pattern. Although this method is used in wave-based or hybrid X-ray simulators, here the applicability and effectiveness of an alternative approach that is based solely on ray tracing of Huygens wavelets are investigated. It is shown that diffraction fringes of a grating-like source are accurately predicted and that diffraction patterns of a ptychography dataset from an experiment with realistic parameters can be sampled well enough to be retrieved by a standard phase-retrieval algorithm. Potentials and limits of this approach are highlighted. It is suggested that it could be applied to study imperfect or non-standard CDI configurations lacking a satisfactory theoretical formulation. The considerable computational effort required by this method is justified by the great flexibility provided for easy simulation of a large-parameter space.

Hawk: the image reconstruction package for coherent X-ray diffractive imaging

2010 ◽  
Vol 43 (6) ◽  
pp. 1535-1539 ◽  
Author(s):  
Filipe R. N. C. Maia ◽  
Tomas Ekeberg ◽  
David van der Spoel ◽  
Janos Hajdu
Keyword(s):  
Open Source ◽  
Graphics Processing Units ◽  
Rapid Development ◽  
Three Dimensional ◽  
Processing Unit ◽  
Diffractive Imaging ◽  
X Ray ◽  
Two Dimensional Image ◽  
Central Processing ◽  
Diffraction Patterns

The past few years have seen a tremendous growth in the field of coherent X-ray diffractive imaging, in large part due to X-ray free-electron lasers which provide a peak brilliance billions of times higher than that of synchrotrons. However, this rapid development in terms of hardware has not been matched on the software side. The release ofHawkis intended to close this gap. To the authors' knowledgeHawkis the first publicly available and fully open source software program for reconstructing images from continuous diffraction patterns. The software handles all steps leading from a raw diffraction pattern to a reconstructed two-dimensional image including geometry determination, background correction, masking and phasing. It also includes preliminary three-dimensional support and support for graphics processing units using the Compute Unified Device Architecture, which speeds up processing by orders of magnitude compared to a single central processing unit.Hawkimplements numerous algorithms and is easily extended. This, in combination with its open-source licence, provides a platform for other groups to test, develop and distribute their own algorithms.Hawkis available under the GNU General Public License from http://xray.bmc.uu.se/hawk.

scholarly journals Experimental 3D coherent diffractive imaging from photon-sparse random projections

IUCrJ ◽  
2019 ◽  
Vol 6 (3) ◽  
pp. 357-365 ◽  
Author(s):  
K. Giewekemeyer ◽  
A. Aquila ◽  
N.-T. D. Loh ◽  
Y. Chushkin ◽  
K. S. Shanks ◽  
...  
Keyword(s):  
Atomic Scale ◽  
Atomic Resolution ◽  
Random Projections ◽  
Energy Storage Materials ◽  
X Rays ◽  
Diffractive Imaging ◽  
X Ray ◽  
Coherent Diffractive Imaging ◽  
Particle Imaging ◽  
Single Particle Imaging

The routine atomic resolution structure determination of single particles is expected to have profound implications for probing structure–function relationships in systems ranging from energy-storage materials to biological molecules. Extremely bright ultrashort-pulse X-ray sources – X-ray free-electron lasers (XFELs) – provide X-rays that can be used to probe ensembles of nearly identical nanoscale particles. When combined with coherent diffractive imaging, these objects can be imaged; however, as the resolution of the images approaches the atomic scale, the measured data are increasingly difficult to obtain and, during an X-ray pulse, the number of photons incident on the 2D detector is much smaller than the number of pixels. This latter concern, the signal `sparsity', materially impedes the application of the method. An experimental analog using a conventional X-ray source is demonstrated and yields signal levels comparable with those expected from single biomolecules illuminated by focused XFEL pulses. The analog experiment provides an invaluable cross check on the fidelity of the reconstructed data that is not available during XFEL experiments. Using these experimental data, it is established that a sparsity of order 1.3 × 10−3 photons per pixel per frame can be overcome, lending vital insight to the solution of the atomic resolution XFEL single-particle imaging problem by experimentally demonstrating 3D coherent diffractive imaging from photon-sparse random projections.

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