scholarly journals Phase-preserving beam expander for biomedical X-ray imaging

2015 ◽  
Vol 22 (3) ◽  
pp. 801-806 ◽  
Author(s):  
Mercedes Martinson ◽  
Nazanin Samadi ◽  
Bassey Bassey ◽  
Ariel Gomez ◽  
Dean Chapman
Keyword(s):  
Imaging Techniques ◽  
Beam Divergence ◽  
Phase Imaging ◽  
Imaging Data ◽  
Double Crystal ◽  
Full Field ◽  
Diffraction Plane ◽  
Double Crystal Monochromator ◽  
Phase Images ◽  
The Difference

The BioMedical Imaging and Therapy beamlines at the Canadian Light Source are used by many researchers to capture phase-based imaging data. These experiments have so far been limited by the small vertical beam size, requiring vertical scanning of biological samples in order to image their full vertical extent. Previous work has been carried out to develop a bent Laue beam-expanding monochromator for use at these beamlines. However, the first attempts exhibited significant distortion in the diffraction plane, increasing the beam divergence and eliminating the usefulness of the monochromator for phase-related imaging techniques. Recent work has been carried out to more carefully match the polychromatic and geometric focal lengths in a so-called `magic condition' that preserves the divergence of the beam and enables full-field phase-based imaging techniques. The new experimental parameters, namely asymmetry and Bragg angles, were evaluated by analysing knife-edge and in-line phase images to determine the effect on beam divergence in both vertical and horizontal directions, using the flat Bragg double-crystal monochromator at the beamline as a baseline. The results show that by using the magic condition, the difference between the two monochromator types is less than 10% in the diffraction plane. Phase fringes visible in test images of a biological sample demonstrate that this difference is small enough to enable in-line phase imaging, despite operating at a sub-optimal energy for the wafer and asymmetry angle that was used.

scholarly journals Development of a bent Laue beam-expanding double-crystal monochromator for biomedical X-ray imaging

2014 ◽  
Vol 21 (3) ◽  
pp. 479-483 ◽  
Author(s):  
Mercedes Martinson ◽  
Nazanin Samadi ◽  
George Belev ◽  
Bassey Bassey ◽  
Rob Lewis ◽  
...  
Keyword(s):  
Beam Quality ◽  
Dynamic Imaging ◽  
Micro Ct ◽  
Imaging Data ◽  
Micro Computed Tomography ◽  
Double Crystal ◽  
Double Crystal Monochromator ◽  
X Ray Imaging ◽  
Beam Expander ◽  
Vertical Beam

The Biomedical Imaging and Therapy (BMIT) beamline at the Canadian Light Source has produced some excellent biological imaging data. However, the disadvantage of a small vertical beam limits its usability in some applications. Micro-computed tomography (micro-CT) imaging requires multiple scans to produce a full projection, and certain dynamic imaging experiments are not possible. A larger vertical beam is desirable. It was cost-prohibitive to build a longer beamline that would have produced a large vertical beam. Instead, it was proposed to develop a beam expander that would create a beam appearing to originate at a source much farther away. This was accomplished using a bent Laue double-crystal monochromator in a non-dispersive divergent geometry. The design and implementation of this beam expander is presented along with results from the micro-CT and dynamic imaging tests conducted with this beam. Flux (photons per unit area per unit time) has been measured and found to be comparable with the existing flat Bragg double-crystal monochromator in use at BMIT. This increase in overall photon count is due to the enhanced bandwidth of the bent Laue configuration. Whilst the expanded beam quality is suitable for dynamic imaging and micro-CT, further work is required to improve its phase and coherence properties.

scholarly journals Characterization of a bent Laue double-crystal beam-expanding monochromator

2017 ◽  
Vol 24 (6) ◽  
pp. 1146-1151 ◽  
Author(s):  
Mercedes Martinson ◽  
Nazanin Samadi ◽  
Xianbo Shi ◽  
Zunping Liu ◽  
Lahsen Assoufid ◽  
...  
Keyword(s):  
Imaging Techniques ◽  
Silicon Crystal ◽  
Large Field ◽  
Element Analysis ◽  
Double Crystal ◽  
Double Crystal Monochromator ◽  
Global Mapping ◽  
Diffraction Effects ◽  
Crystal Wafer ◽  
Bent Crystals

A bent Laue double-crystal monochromator system has been designed for vertically expanding the X-ray beam at the Canadian Light Source's BioMedical Imaging and Therapy beamlines. Expansion by a factor of 12 has been achieved without deteriorating the transverse coherence of the beam, allowing phase-based imaging techniques to be performed with high flux and a large field of view. However, preliminary studies revealed a lack of uniformity in the beam, presumed to be caused by imperfect bending of the silicon crystal wafers used in the system. Results from finite-element analysis of the system predicted that the second crystal would be most severely affected and has been shown experimentally. It has been determined that the majority of the distortion occurs in the second crystal and is likely caused by an imperfection in the surface of the bending frame. Measurements were then taken to characterize the bending of the crystal using both mechanical and diffraction techniques. In particular, two techniques commonly used to map dislocations in crystal structures have been adapted to map local curvature of the bent crystals. One of these, a variation of Berg–Berrett topography, has been used to quantify the diffraction effects caused by the distortion of the crystal wafer. This technique produces a global mapping of the deviation of the diffraction angle relative to a perfect cylinder. This information is critical for improving bending and measuring tolerances of imperfections by correlating this mapping to areas of missing intensity in the beam.

scholarly journals Melittin-induced alterations in morphology and deformability of human red blood cells using quantitative phase imaging techniques

2016 ◽  
Author(s):  
Joonseok Hur ◽  
Kyoohyun Kim ◽  
SangYun Lee ◽  
HyunJoo Park ◽  
YongKeun Park
Keyword(s):  
Refractive Index ◽  
Red Blood Cells ◽  
Blood Cells ◽  
Imaging Techniques ◽  
Phase Imaging ◽  
Quantitative Phase Imaging ◽  
Active Molecule ◽  
Quantitative Phase ◽  
Human Red Blood Cells ◽  
Phase Images

Here, the actions of melittin, the active molecule of apitoxin or bee venom, were investigated on human red blood cells (RBCs) using quantitative phase imaging techniques. High-resolution realtime 3-D refractive index (RI) measurements and dynamic 2-D phase images of individual melittin-bound RBCs enabled in-depth examination of melittin-induced biophysical alterations of the cells. From the measurements, morphological, biochemical, and mechanical alterations of the RBCs were analyzed quantitatively. Furthermore, leakage of haemoglobin (Hb) inside the RBCs at high melittin concentration was also investigated.

scholarly journals Optimizing the energy bandwidth for transmission full-field X-ray microscopy experiments

2022 ◽  
Vol 29 (1) ◽  
Author(s):  
Malte Storm ◽  
Florian Döring ◽  
Shashidhara Marathe ◽  
Silvia Cipiccia ◽  
Christian David ◽  
...  
Keyword(s):  
Limited Effect ◽  
Double Crystal ◽  
Full Field ◽  
X Ray ◽  
Double Crystal Monochromator ◽  
X Ray Imaging ◽  
Order Of Magnitude ◽  
Chromatic Aberrations ◽  
The Impact ◽  
Theoretical Considerations

Full-field transmission X-ray microscopy (TXM) is a very potent high-resolution X-ray imaging technique. However, it is challenging to achieve fast acquisitions because of the limited efficiency of the optics. Using a broader energy bandwidth, for example using a multilayer monochromator, directly increases the flux in the experiment. The advantage of more counts needs to be weighed against a deterioration in achievable resolution because focusing optics show chromatic aberrations. This study presents theoretical considerations of how much the resolution is affected by an increase in bandwidth as well as measurements at different energy bandwidths (ΔE/E = 0.013%, 0.27%, 0.63%) and the impact on achievable resolution. It is shown that using a multilayer monochromator instead of a classical silicon double-crystal monochromator can increase the flux by an order of magnitude with only a limited effect on the resolution.

A DOUBLE CRYSTAL MONOCHROMATOR FOR SOFT X-RAY BEAM LINE OF UVSOR

1986 ◽  
Vol 47 (C8) ◽  
pp. C8-135-C8-137
Author(s):  
T. MURATA ◽  
T. MATSUKAWA ◽  
M. MORI ◽  
M. OBASHI ◽  
S.-I. NAO-E ◽  
...  
Keyword(s):  
Beam Line ◽  
Double Crystal ◽  
X Ray ◽  
Double Crystal Monochromator

Full-field X-ray diffraction microscopy using polymeric compound refractive lenses

2014 ◽  
Vol 47 (6) ◽  
pp. 1882-1888 ◽  
Author(s):  
J. Hilhorst ◽  
F. Marschall ◽  
T. N. Tran Thi ◽  
A. Last ◽  
T. U. Schülli
Keyword(s):  
Imaging Techniques ◽  
Light And Electron Microscopy ◽  
Added Value ◽  
Acquisition Time ◽  
Imaging Method ◽  
X Ray Diffraction ◽  
Polymeric Compound ◽  
Full Field ◽  
X Ray ◽  
Diffraction Imaging

Diffraction imaging is the science of imaging samples under diffraction conditions. Diffraction imaging techniques are well established in visible light and electron microscopy, and have also been widely employed in X-ray science in the form of X-ray topography. Over the past two decades, interest in X-ray diffraction imaging has taken flight and resulted in a wide variety of methods. This article discusses a new full-field imaging method, which uses polymer compound refractive lenses as a microscope objective to capture a diffracted X-ray beam coming from a large illuminated area on a sample. This produces an image of the diffracting parts of the sample on a camera. It is shown that this technique has added value in the field, owing to its high imaging speed, while being competitive in resolution and level of detail of obtained information. Using a model sample, it is shown that lattice tilts and strain in single crystals can be resolved simultaneously down to 10−3° and Δa/a= 10−5, respectively, with submicrometre resolution over an area of 100 × 100 µm and a total image acquisition time of less than 60 s.

Managing the Edentulous Mandible using Recent Technological Developments: A Case Study

2013 ◽  
Vol 2 (2) ◽  
pp. 50-54
Author(s):  
Ashok Sethi ◽  
Thomas Kaus ◽  
Naresh Sharma ◽  
Peter Sochor
Keyword(s):  
Computed Tomography ◽  
Spatial Information ◽  
Imaging Techniques ◽  
Accurate Information ◽  
Imaging Data ◽  
Surgical Guide ◽  
Prosthetic Reconstruction ◽  
Anterior Teeth ◽  
Edentulous Mandible ◽  
Cad Cam

Safe clinical practice in implant dentistry requires an accurate investigation of the availability of bone for implant placement and the avoidance of critical anatomical structures. Modern imaging techniques using computed tomography (CT) and cone beam computed tomography (CBCT) provide the clinician with the required information. The imaging thus obtained provides accurate representation of the height, width and length of the available bone.1 In addition, whenever adequate radiation dose is used, accurate information about the bone density in Hounsfield units can be obtained. Important spatial information regarding the orientation of the ridges and the relationship to the proposed prosthetic reconstruction can be obtained with the aid of radiopaque templates during the acquisition of CT scan data. Modern software also provides the facility to decide interactively upon the positioning of the implants and is able to relate this to a stereolithographic model constructed from the imaging data. A surgical guide for the accurate positioning of the implants can be constructed. The construction of screw retained prostheses is fraught with difficulties regarding the accuracy of the construction. Accurate fit of the prosthesis is difficult to obtain due to the inherent errors in impression taking, component discrepancies, investing and casting inaccuracies.2,3 CAD/CAM technology eliminates the inaccuracies involved with the investing and casting of superstructures. Clinical Case This case describes the management of an 84 year old female patient, who had recently lost her remaining mandibular anterior teeth. This resulted in the patient's inability to wear conventional dentures in the mandible.

Spatial imaging of monochromatic hard x‐rays from an APS undulator by the Kohzu double‐crystal monochromator (abstract)

1996 ◽  
Vol 67 (9) ◽  
pp. 3348-3348
Author(s):  
D.M. Mills ◽  
W.K. Lee ◽  
M. Keeffe ◽  
D.R. Haeffner ◽  
P. Fernandez
Keyword(s):  
X Rays ◽  
Double Crystal ◽  
Double Crystal Monochromator

Optimization of a double crystal monochromator

2021 ◽  
Author(s):  
Zheng Jiang ◽  
Eryan Wang ◽  
Ruiqiang Song ◽  
Siming Guo ◽  
Jinjie Wu ◽  
...  
Keyword(s):  
Double Crystal ◽  
Double Crystal Monochromator

scholarly journals Full-field imaging of thermal and acoustic dynamics in an individual nanostructure using tabletop high harmonic beams

2018 ◽  
Vol 4 (10) ◽  
pp. eaau4295 ◽  
Author(s):  
Robert M. Karl ◽  
Giulia F. Mancini ◽  
Joshua L. Knobloch ◽  
Travis D. Frazer ◽  
Jorge N. Hernandez-Charpak ◽  
...  
Keyword(s):  
Functional Imaging ◽  
Extreme Ultraviolet ◽  
Imaging Techniques ◽  
High Harmonic ◽  
Three Dimensional ◽  
Dynamic Imaging ◽  
Significant Advance ◽  
Grand Challenge ◽  
Diffractive Imaging ◽  
Full Field

Imaging charge, spin, and energy flow in materials is a current grand challenge that is relevant to a host of nanoenhanced systems, including thermoelectric, photovoltaic, electronic, and spin devices. Ultrafast coherent x-ray sources enable functional imaging on nanometer length and femtosecond timescales particularly when combined with advances in coherent imaging techniques. Here, we combine ptychographic coherent diffractive imaging with an extreme ultraviolet high harmonic light source to directly visualize the complex thermal and acoustic response of an individual nanoscale antenna after impulsive heating by a femtosecond laser. We directly image the deformations induced in both the nickel tapered nanoantenna and the silicon substrate and see the lowest-order generalized Lamb wave that is partially confined to a uniform nanoantenna. The resolution achieved—sub–100 nm transverse and 0.5-Å axial spatial resolution, combined with ≈10-fs temporal resolution—represents a significant advance in full-field dynamic imaging capabilities. The tapered nanoantenna is sufficiently complex that a full simulation of the dynamic response would require enormous computational power. We therefore use our data to benchmark approximate models and achieve excellent agreement between theory and experiment. In the future, this work will enable three-dimensional functional imaging of opaque materials and nanostructures that are sufficiently complex that their functional properties cannot be predicted.

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