scholarly journals Artifact removal in the contour areas of SAXS-CT images by Tikhonov-L1 minimization

2021 ◽  
Vol 54 (6) ◽  
Author(s):  
Hiroki Ogawa ◽  
Shunsuke Ono ◽  
Yuki Watanabe ◽  
Yukihiro Nishikawa ◽  
Shotaro Nishitsuji ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Incident Beam ◽  
Ct Image ◽  
Characteristic Parameters ◽  
Artifact Removal ◽  
L1 Minimization ◽  
X Ray ◽  
Nanoscale Structures ◽  
X Ray Scattering ◽  
Surface Length

Small-angle X-ray scattering (SAXS) coupled with computed tomography (CT), denoted SAXS-CT, has enabled the spatial distribution of the characteristic parameters (e.g. size, shape, surface, length) of nanoscale structures inside samples to be visualized. In this work, a new scheme with Tikhonov regularization was developed to remove the effects of artifacts caused by streak scattering originating from the reflection of the incident beam in the contour regions of the sample. The noise due to streak scattering was successfully removed from the sinogram image and hence the CT image could be reconstructed free from artifacts in the contour regions.

A feasibility study of time of flight cone beam computed tomography imaging

2021 ◽  
pp. 1-14
Author(s):  
Ignacio O. Romero ◽  
Changqing Li
Keyword(s):  
Computed Tomography ◽  
Cone Beam Computed Tomography ◽  
Time Of Flight ◽  
Cone Beam ◽  
X Ray ◽  
X Ray Scattering ◽  
Scattering Effects ◽  
Breast Phantom ◽  
Scatter Reduction ◽  
Strong Scattering

BACKGROUND: The time of flight (TOF) cone beam computed tomography (CBCT) was recently shown to reduce the X-ray scattering effects by 95%and improve the image CNR by 110%for large volume objects. The advancements in X-ray sources like in compact Free Electron Lasers (FEL) and advancements in detector technology show potential for the TOF method to be feasible in CBCT when imaging large objects. OBJECTIVE: To investigate feasibility and efficacy of TOF CBCT in imaging smaller objects with different targets such as bones and tumors embedded inside the background. METHODS: The TOF method used in this work was verified using a 24cm phantom. Then, the GATE software was used to simulate the CBCT imaging of an 8 cm diameter cylindrical water phantom with two bone targets using a modeled 20 keV quasi-energetic FEL source and various TOF resolutions ranging from 1 to 1000 ps. An inhomogeneous breast phantom of similar size with tumor targets was also imaged using the same system setup. RESULTS: The same results were obtained in the 24cm phantom, which validated the applied CBCT simulation approach. For the case of 8cm cylindrical phantom and bone target, a TOF resolution of 10 ps improved the image contrast-to-noise ratio (CNR) by 57%and reduced the scatter-to-primary ratio (SPR) by 8.63. For the case of breast phantom and tumor target, image CNR was enhanced by 12%and SPR was reduced by 1.35 at 5 ps temporal resolution. CONCLUSIONS: This study indicates that a TOF resolution below 10 ps is required to observe notable enhancements in the image quality and scatter reduction for small objects around 8cm in diameter. The strong scattering targets such as bone can result in substantial improvements by using TOF CBCT.

Polarization analysis in magnetic x‐ray scattering using 45° linearly polarized x‐ray incident beam (abstract)

1992 ◽  
Vol 63 (1) ◽  
pp. 1176-1176
Author(s):  
Koichi Mori ◽  
Kazumichi Namikawa ◽  
Yoshisato Funahashi ◽  
Yasuo Higashi ◽  
Masami Ando
Keyword(s):  
Incident Beam ◽  
Polarization Analysis ◽  
X Ray ◽  
X Ray Scattering ◽  
Linearly Polarized ◽  
Ray Scattering

Collimating Montel mirror as part of a multi-crystal analyzer system for resonant inelastic X-ray scattering

2016 ◽  
Vol 23 (4) ◽  
pp. 880-886 ◽  
Author(s):  
Jungho Kim ◽  
Xianbo Shi ◽  
Diego Casa ◽  
Jun Qian ◽  
XianRong Huang ◽  
...  
Keyword(s):  
Energy Resolution ◽  
Incident Beam ◽  
X Rays ◽  
X Ray ◽  
X Ray Scattering ◽  
Angular Acceptance ◽  
Crystal Analyzer ◽  
Present Design ◽  
Photon Source ◽  
Ray Scattering

Advances in resonant inelastic X-ray scattering (RIXS) have come in lockstep with improvements in energy resolution. Currently, the best energy resolution at the IrL3-edge stands at ∼25 meV, which is achieved using a diced Si(844) spherical crystal analyzer. However, spherical analyzers are limited by their intrinsic reflection width. A novel analyzer system using multiple flat crystals provides a promising way to overcome this limitation. For the present design, an energy resolution at or below 10 meV was selected. Recognizing that the angular acceptance of flat crystals is severely limited, a collimating element is essential to achieve the necessary solid-angle acceptance. For this purpose, a laterally graded, parabolic, multilayer Montel mirror was designed for use at the IrL3-absorption edge. It provides an acceptance larger than 10 mrad, collimating the reflected X-ray beam to smaller than 100 µrad, in both vertical and horizontal directions. The performance of this mirror was studied at beamline 27-ID at the Advanced Photon Source. X-rays from a diamond (111) monochromator illuminated a scattering source of diameter 5 µm, generating an incident beam on the mirror with a well determined divergence of 40 mrad. A flat Si(111) crystal after the mirror served as the divergence analyzer. From X-ray measurements, ray-tracing simulations and optical metrology results, it was established that the Montel mirror satisfied the specifications of angular acceptance and collimation quality necessary for a high-resolution RIXS multi-crystal analyzer system.

Scatterless hybrid metal–single-crystal slit for small-angle X-ray scattering and high-resolution X-ray diffraction

2008 ◽  
Vol 41 (6) ◽  
pp. 1134-1139 ◽  
Author(s):  
Youli Li ◽  
Roy Beck ◽  
Tuo Huang ◽  
Myung Chul Choi ◽  
Morito Divinagracia
Keyword(s):  
High Resolution ◽  
Single Crystal ◽  
Small Angle ◽  
Incident Beam ◽  
Single Crystal Substrate ◽  
X Ray Diffraction ◽  
Metal Base ◽  
X Ray ◽  
X Ray Scattering ◽  
Ray Scattering

A simple hybrid design has been developed to produce practically scatterless aperture slits for small-angle X-ray scattering and high-resolution X-ray diffraction. The hybrid slit consists of a rectangular single-crystal substrate (e.g.Si or Ge) bonded to a high-density metal base with a large taper angle (> 10°). The beam-defining single-crystal tip is oriented far from any Bragg peak position with respect to the incident beam and hence produces none of the slit scattering commonly associated with conventional metal slits. It has been demonstrated that the incorporation of the scatterless slits leads to a much simplified design in small-angle X-ray scattering instruments employing only one or two apertures, with dramatically increased intensity (a threefold increase observed in the test setup) and improved low-angle resolution.

scholarly journals Development of combined microstructure and structure characterization facility forin situandoperandostudies at the Advanced Photon Source

2018 ◽  
Vol 51 (3) ◽  
pp. 867-882 ◽  
Author(s):  
Jan Ilavsky ◽  
Fan Zhang ◽  
Ross N. Andrews ◽  
Ivan Kuzmenko ◽  
Pete R. Jemian ◽  
...  
Keyword(s):  
Small Angle ◽  
National Laboratory ◽  
Argonne National Laboratory ◽  
Incident Beam ◽  
Evolutionary Development ◽  
X Ray ◽  
X Ray Scattering ◽  
Wide Range ◽  
Photon Source ◽  
Ray Scattering

Following many years of evolutionary development, first at the National Synchrotron Light Source, Brookhaven National Laboratory, and then at the Advanced Photon Source (APS), Argonne National Laboratory, the APS ultra-small-angle X-ray scattering (USAXS) facility has been transformed by several new developments. These comprise a conversion to higher-order crystal optics and higher X-ray energies as the standard operating mode, rapid fly scan measurements also as a standard operational mode, automated contiguous pinhole small-angle X-ray scattering (SAXS) measurements at intermediate scattering vectors, and associated rapid wide-angle X-ray scattering (WAXS) measurements for X-ray diffraction without disturbing the sample geometry. With each mode using the USAXS incident beam optics upstream of the sample, USAXS/SAXS/WAXS measurements can now be made within 5 min, allowingin situandoperandomeasurement capabilities with great flexibility under a wide range of sample conditions. These developments are described, together with examples of their application to investigate materials phenomena of technological importance. Developments of two novel USAXS applications, USAXS-based X-ray photon correlation spectroscopy and USAXS imaging, are also briefly reviewed.

scholarly journals Automated Analysis of Spatially Resolved X-ray Scattering and Micro Computed Tomography of Artificial and Natural Enamel Carious Lesions

2018 ◽  
Vol 4 (6) ◽  
pp. 81 ◽  
Author(s):  
Hans Deyhle ◽  
Shane White ◽  
Lea Botta ◽  
Marianne Liebi ◽  
Manuel Guizar-Sicairos ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Automated Analysis ◽  
Micro Computed Tomography ◽  
X Ray ◽  
Spatially Resolved ◽  
X Ray Scattering ◽  
Carious Lesions ◽  
Ray Scattering

Improving the efficiency of small-angle x-ray scattering computed tomography using the OSEM algorithm

2017 ◽  
Vol 56 (30) ◽  
pp. 8326 ◽  
Author(s):  
Tao Hu ◽  
Yudan Wang ◽  
Guohao Du ◽  
Yuzhu Wang ◽  
Wenqiang Hua ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Small Angle ◽  
X Ray ◽  
X Ray Scattering ◽  
Ray Scattering

SWING detection vacuum tunnel

2011 ◽  
Vol 1 (MEDSI-6) ◽  
Author(s):  
D. Dalle ◽  
J. Perez ◽  
O. Lyon ◽  
P. Feret ◽  
C. Menneglier ◽  
...  
Keyword(s):  
Small Angle ◽  
Vacuum Chamber ◽  
Incident Beam ◽  
Angular Range ◽  
Scattered Intensity ◽  
Long Distance ◽  
General Design ◽  
X Ray ◽  
X Ray Scattering ◽  
Ray Scattering

The SWING beamline is dedicated to the study of the small-angle X-ray scattering. In order to have the possibility to detect scattered intensity very close to the incident beam, it is absolutely necessary to install the detector at a long distance from the sample. In addition, it is easy to change the detector's position to access a wider angular range. A long and large vacuum chamber, the ‘tunnel’, has been designed with specific mechanisms inside to control the detector's position with micrometre resolution. Special attention has been given so as to offer a very useful device to the users. The paper will present the general design of the tunnel equipped with ancillary devices such as very narrow and stiff beam stoppers, diode holders and beam attenuators.

scholarly journals Improving grazing-incidence small-angle X-ray scattering–computed tomography images by total variation minimization

2020 ◽  
Vol 53 (1) ◽  
pp. 140-147
Author(s):  
Hiroki Ogawa ◽  
Shunsuke Ono ◽  
Yukihiro Nishikawa ◽  
Akihiko Fujiwara ◽  
Taizo Kabe ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Image Quality ◽  
Total Variation ◽  
Small Angle ◽  
Grazing Incidence ◽  
Ct Images ◽  
Measurement Time ◽  
X Ray ◽  
X Ray Scattering ◽  
Ray Scattering

Grazing-incidence small-angle X-ray scattering (GISAXS) coupled with computed tomography (CT) has enabled the visualization of the spatial distribution of nanostructures in thin films. 2D GISAXS images are obtained by scanning along the direction perpendicular to the X-ray beam at each rotation angle. Because the intensities at the q positions contain nanostructural information, the reconstructed CT images individually represent the spatial distributions of this information (e.g. size, shape, surface, characteristic length). These images are reconstructed from the intensities acquired at angular intervals over 180°, but the total measurement time is prolonged. This increase in the radiation dosage can cause damage to the sample. One way to reduce the overall measurement time is to perform a scanning GISAXS measurement along the direction perpendicular to the X-ray beam with a limited interval angle. Using filtered back-projection (FBP), CT images are reconstructed from sinograms with limited interval angles from 3 to 48° (FBP-CT images). However, these images are blurred and have a low image quality. In this study, to optimize the CT image quality, total variation (TV) regularization is introduced to minimize sinogram image noise and artifacts. It is proposed that the TV method can be applied to downsampling of sinograms in order to improve the CT images in comparison with the FBP-CT images.

X-Ray Microfocus Radioscopy and Computed Tomography for Failure Analysis

1996 ◽  
Author(s):  
R.H. Bossi ◽  
D.A. Cross ◽  
R.A. Mickelsen
Keyword(s):  
Computed Tomography ◽  
Failure Analysis ◽  
Conventional Radiography ◽  
Ct Images ◽  
Ct Image ◽  
Video Monitor ◽  
Cross Sectional ◽  
X Ray ◽  
Technical Accuracy ◽  
Conventional Film

Abstract X-ray microfocus radioscopy and computed tomography (CT) offer detailed information on the internal assembly and material condition of objects under failure analysis investigation. Using advanced systems for the acquisition of radioscopic and CT images, failure analysis investigations are improved in technical accuracy at a reduced schedule and cost over alternative approaches. A versatile microfocus radioscopic system with CT capability has been successfully implemented as a standard tool in the Boeing Defense & Space Group Failure Analysis Laboratory. Using this tool, studies of electronic, electromechanical and composite material items have been performed. Such a system can pay for itself within two years through higher productivity of the laboratory, increased laboratory value to the company and resolution of critical problems whose worth far exceeds the value of the equipment. The microfocus X-ray source provides projection magnification images that exceed the sensitivity to fine detail that can be obtained with conventional film radiography. Radioscopy, which provides real-time images on a video monitor, allows objects to be readily manipulated and oriented for optimum x-ray evaluation, or monitored during dynamic processes to check performance. Combined with an accurate manipulating stage and data acquisition system x-ray measurements can be used for CT image reconstruction. The CT image provides a cross sectional view of the interior of an object without the interference of superposition of features found in conventional radiography. Accurate dimensional measurements and material constituent identification are possible from the CT images. By taking multiple, contiguous CT slices entire three dimensional data files can be generated of objects.

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