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Title: An energy dispersive bent Laue monochromator for K-edge subtraction imaging

Abstract

K-Edge Subtraction (KES) is a powerful synchrotron imaging method that allows the quantifiable determination of a contrast element (e.g. iodine) and matrix material (usually represented as water) in both projection imaging and computed tomography. A bent Laue monochromator has been developed that has very good focal and energy dispersive properties for KES. Approximately 5% of the vertical beam profile is involved in “edge crossing” energies, thus no splitter is employed as has been done with previous implementations where approximately 33% of the beam size was blocked. The beam can be narrowed vertically allowing a smaller crossover angle than a splitter based system which minimizes artifacts. The combination of good spatial resolution, energy dispersive properties, flux and a unique approach to data analysis make this system nearly ideal for KES.

Authors:
 [1]; ;  [2]; ;  [3];  [4];  [5]
  1. Biomedical Engineering Division, University of Saskatchewan, Saskatoon, SK (Canada)
  2. Physics and Engineering Physics, University of Saskatchewan, Saskatoon, SK (Canada)
  3. Canadian Light Source Inc., Saskatoon, SK (Canada)
  4. Anatomy and Cell Biology, University of Saskatchewan, Saskatoon, SK (Canada)
  5. (Canada)
Publication Date:
OSTI Identifier:
22608389
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 1741; Journal Issue: 1; Conference: SRI2015: 12. international conference on synchrotron radiation instrumentation, New York, NY (United States), 6-10 Jul 2015; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; APPROXIMATIONS; BEAM PROFILES; BEAMS; COMPUTERIZED TOMOGRAPHY; DATA ANALYSIS; IMAGES; MONOCHROMATORS; SPATIAL RESOLUTION; SYNCHROTRONS

Citation Formats

Samadi, Nazanin, E-mail: Nazanin.Samadi@usask.ca, Martinson, Mercedes, Bassey, Bassey, Gomez, Ariel, Belev, George, Chapman, Dean, and Canadian Light Source Inc., Saskatoon, SK. An energy dispersive bent Laue monochromator for K-edge subtraction imaging. United States: N. p., 2016. Web. doi:10.1063/1.4952876.
Samadi, Nazanin, E-mail: Nazanin.Samadi@usask.ca, Martinson, Mercedes, Bassey, Bassey, Gomez, Ariel, Belev, George, Chapman, Dean, & Canadian Light Source Inc., Saskatoon, SK. An energy dispersive bent Laue monochromator for K-edge subtraction imaging. United States. doi:10.1063/1.4952876.
Samadi, Nazanin, E-mail: Nazanin.Samadi@usask.ca, Martinson, Mercedes, Bassey, Bassey, Gomez, Ariel, Belev, George, Chapman, Dean, and Canadian Light Source Inc., Saskatoon, SK. Wed . "An energy dispersive bent Laue monochromator for K-edge subtraction imaging". United States. doi:10.1063/1.4952876.
@article{osti_22608389,
title = {An energy dispersive bent Laue monochromator for K-edge subtraction imaging},
author = {Samadi, Nazanin, E-mail: Nazanin.Samadi@usask.ca and Martinson, Mercedes and Bassey, Bassey and Gomez, Ariel and Belev, George and Chapman, Dean and Canadian Light Source Inc., Saskatoon, SK},
abstractNote = {K-Edge Subtraction (KES) is a powerful synchrotron imaging method that allows the quantifiable determination of a contrast element (e.g. iodine) and matrix material (usually represented as water) in both projection imaging and computed tomography. A bent Laue monochromator has been developed that has very good focal and energy dispersive properties for KES. Approximately 5% of the vertical beam profile is involved in “edge crossing” energies, thus no splitter is employed as has been done with previous implementations where approximately 33% of the beam size was blocked. The beam can be narrowed vertically allowing a smaller crossover angle than a splitter based system which minimizes artifacts. The combination of good spatial resolution, energy dispersive properties, flux and a unique approach to data analysis make this system nearly ideal for KES.},
doi = {10.1063/1.4952876},
journal = {AIP Conference Proceedings},
number = 1,
volume = 1741,
place = {United States},
year = {Wed Jul 27 00:00:00 EDT 2016},
month = {Wed Jul 27 00:00:00 EDT 2016}
}
  • No abstract prepared.
  • A bent Bragg–Laue monochromator (BLM) is proposed for high-energy X-ray (~25–60 keV) beamlines. The BLM has the unique feature of bi-directional focusing. A sagittally bent Laue crystal can focus the large horizontal fan of a bending magnet or wiggler source. A meridionally bent Bragg crystal focuses the beam vertically and corrects for the anticlastic bending effects of the Laue crystal. This monochromator geometry relies on the crystal orientations being optimized. We show that the focusing condition and Rowland condition can be simultaneously satisfied at a given energy. A detailed ray tracings indicate that a BLM can provide similar energy resolutionmore » and higher flux density compared to a sagittally bent double-Laue monochromator configuration. A prototype BLM with a symmetric Bragg crystal and an asymmetric Laue crystal was tested. Matching of the bend radii of the two crystals in the meridional direction was demonstrated. Generally, the horizontal acceptance of the sagittally bent Laue crystal is limited by the large curvature. This horizontal BLM acceptance could be increased by translating the Laue crystal along its sagittal bending axis.« less
  • We have developed a compact short focal distance Bent Crystal Laue Analyzer (BCLA) for Cu speciation studies of biological systems with specific applications to cancer biology. The system provides high energy resolution and high background rejection. The system is composed of an aluminum block serving as a log spiral bender for a 15 micron thick Silicon 111 crystal and a set of soller slits. The energy resolution of the BCLA--about 14 eV at the Cu K{alpha} line-- allows resolution of the Cu K{alpha}{sub 1} and CuK{alpha}{sub 2} lines. The system is easily aligned by using a set of motorized XYZmore » linear stages. Two operation modes are available: incident energy scans (IES) and emission energy scans (EES). IES allows scanning of the incident energy while the BCLA system is maintained at a preselected fixed position - typically CuK{alpha}{sub 1} line. EES is used when the incident energy is fixed and the analyzer is scanned to provide the peak profile of the emission lines of Cu.« less
  • The effect of the energy dispersion of a quasi-monochromatic x-ray beam on the performance of a dual-energy x-ray imaging system is studied by means of Monte Carlo simulations using MCNPX (Monte Carlo N-Particle eXtended) version 2.6.0. In particular, the case of subtraction imaging at the iodine K-edge, suitable for angiographic imaging application, is investigated. The average energies of the two beams bracketing the iodine K-edge are set to the values of 31.2 and 35.6 keV corresponding to the ones obtained with a compact source based on a conventional x-ray tube and a mosaic crystal monochromator. The energy dispersion of themore » two beams is varied between 0 and 10 keV of full width at half-maximum (FWHM). The signal and signal-to-noise ratio produced in the simulated images by iodine-filled cavities (simulating patient vessels) drilled in a PMMA phantom are studied as a function of the x-ray energy dispersion. The obtained results show that, for the considered energy separation of 4.4 keV, no dramatic deterioration of the image quality is observed with increasing x-ray energy dispersion up to a FWHM of about 2.35 keV. The case of different beam energies is also investigated by means of fast simulations of the phantom absorption.« less
  • Background: The potential transfer of engineered nanoparticles (ENPs) from plants into the food chain has raised widespread concerns. In order to investigate the effects of ENPs on plants, young cabbage plants (Brassica oleracea) were exposed to a hydroponic system containing yttrium oxide (yttria) ENPs. The objective of this study was to reveal the impacts of NPs on plants by using K-edge subtraction imaging technique. Results: Using synchrotron dual-e nergy X-ray micro-tomography with K-edge subtraction technique, we studied the uptake, accumulation, distribution and concentration mapping of yttria ENPs in cabbage plants. It was found that yttria ENPs were uptaken by themore » cabbage roots but did not effectively transferred and mobilized through the cabbage stem and leaves. This could be due to the accumulation of yttria ENPs blocked at primary-lateral-root junction. Instead, non-yttria minerals were found in the xylem vessels of roots and stem. Conclusions: Synchrotron dual-energy X-ray micro-tomography is an effective method to observe yttria NPs inside the cabbage plants in both whole body and microscale level. Furthermore, the blockage of a plant's roots by nanoparticles is likely the first and potentially fatal environmental effect of such type of nanoparticles.« less