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Miao H, Gomella AA, Chedid N, Chen L, Wen H. Fabrication of 200 nm period hard X-ray phase gratings. NANO LETTERS 2014; 14:3453-8. [PMID: 24845537 PMCID: PMC4055044 DOI: 10.1021/nl5009713] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Far field X-ray grating interferometry achieves extraordinary phase sensitivity in imaging weakly absorbing samples, provided that the grating period is within the transverse coherence length of the X-ray source. Here we describe a cost-efficient process to fabricate large area, 100 nm half-pitch hard X-ray phase gratings with an aspect ratio of 32. The nanometric gratings are suitable for ordinary compact X-ray sources having low spatial coherence, as demonstrated by X-ray diffraction experiments.
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Affiliation(s)
- Houxun Miao
- Imaging
Physics Laboratory, Biochemistry and Biophysics Center, National Heart,
Lung and Blood Institute, National Institutes
of Health, Bethesda, Maryland 20892, United
States
- E-mail:
(H.M.)
| | - Andrew A. Gomella
- Imaging
Physics Laboratory, Biochemistry and Biophysics Center, National Heart,
Lung and Blood Institute, National Institutes
of Health, Bethesda, Maryland 20892, United
States
| | - Nicholas Chedid
- Imaging
Physics Laboratory, Biochemistry and Biophysics Center, National Heart,
Lung and Blood Institute, National Institutes
of Health, Bethesda, Maryland 20892, United
States
| | - Lei Chen
- Center
for Nanoscale Science and Technology, National
Institute of Standards and Technology, Gaithersburg, Maryland 20899, United States
| | - Han Wen
- Imaging
Physics Laboratory, Biochemistry and Biophysics Center, National Heart,
Lung and Blood Institute, National Institutes
of Health, Bethesda, Maryland 20892, United
States
- E-mail: (H.W.)
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Wen H, Wolfe DE, Gomella AA, Miao H, Xiao X, Liu C, Lynch SK, Morgan N. Interferometric hard x-ray phase contrast imaging at 204 nm grating period. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2013; 84:013706. [PMID: 23387658 PMCID: PMC3574100 DOI: 10.1063/1.4788910] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2012] [Accepted: 01/07/2013] [Indexed: 05/23/2023]
Abstract
We report on hard x-ray phase contrast imaging experiments using a grating interferometer of approximately 1/10th the grating period achieved in previous studies. We designed the gratings as a staircase array of multilayer stacks which are fabricated in a single thin film deposition process. We performed the experiments at 19 keV x-ray energy and 0.8 μm pixel resolution. The small grating period resulted in clear separation of different diffraction orders and multiple images on the detector. A slitted beam was used to remove overlap of the images from the different diffraction orders. The phase contrast images showed detailed features as small as 10 μm, and demonstrated the feasibility of high resolution x-ray phase contrast imaging with nanometer scale gratings.
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Affiliation(s)
- Han Wen
- Imaging Physic Laboratory, Biophysics and Biochemistry Center, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, Maryland 20892, USA.
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Bravin A, Coan P, Suortti P. X-ray phase-contrast imaging: from pre-clinical applications towards clinics. Phys Med Biol 2012; 58:R1-35. [PMID: 23220766 DOI: 10.1088/0031-9155/58/1/r1] [Citation(s) in RCA: 379] [Impact Index Per Article: 31.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Phase-contrast x-ray imaging (PCI) is an innovative method that is sensitive to the refraction of the x-rays in matter. PCI is particularly adapted to visualize weakly absorbing details like those often encountered in biology and medicine. In past years, PCI has become one of the most used imaging methods in laboratory and preclinical studies: its unique characteristics allow high contrast 3D visualization of thick and complex samples even at high spatial resolution. Applications have covered a wide range of pathologies and organs, and are more and more often performed in vivo. Several techniques are now available to exploit and visualize the phase-contrast: propagation- and analyzer-based, crystal and grating interferometry and non-interferometric methods like the coded aperture. In this review, covering the last five years, we will give an overview of the main theoretical and experimental developments and of the important steps performed towards the clinical implementation of PCI.
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Affiliation(s)
- Alberto Bravin
- European Synchrotron Radiation Facility, 6 rue Horowitz, 38043 Grenoble Cedex, France.
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Lynch SK, Liu C, Morgan NY, Xiao X, Gomella AA, Mazilu D, Bennett EE, Assoufid L, de Carlo F, Wen H. Fabrication of 200 nanometer period centimeter area hard x-ray absorption gratings by multilayer deposition. JOURNAL OF MICROMECHANICS AND MICROENGINEERING : STRUCTURES, DEVICES, AND SYSTEMS 2012; 22:105007. [PMID: 23066175 PMCID: PMC3468157 DOI: 10.1088/0960-1317/22/10/105007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
We describe the design and fabrication trials of x-ray absorption gratings of 200 nm period and up to 100:1 depth-to-period ratios for full-field hard x-ray imaging applications. Hard x-ray phase-contrast imaging relies on gratings of ultra-small periods and sufficient depth to achieve high sensitivity. Current grating designs utilize lithographic processes to produce periodic vertical structures, where grating periods below 2.0 μm are difficult due to the extreme aspect ratios of the structures. In our design, multiple bilayers of x-ray transparent and opaque materials are deposited on a staircase substrate, and mostly on the floor surfaces of the steps only. When illuminated by an x-ray beam horizontally, the multilayer stack on each step functions as a micro-grating whose grating period is the thickness of a bilayer. The array of micro-gratings over the length of the staircase works as a single grating over a large area when continuity conditions are met. Since the layers can be nanometers thick and many microns wide, this design allows sub-micron grating periods and sufficient grating depth to modulate hard x-rays. We present the details of the fabrication process and diffraction profiles and contact radiography images showing successful intensity modulation of a 25 keV x-ray beam.
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Affiliation(s)
- S K Lynch
- Imaging Physics Lab, Biochemistry and Biophysics Center, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD, 20892, USA
| | - C Liu
- X-Ray Science Division, Advanced Photon Source, Argonne National Laboratory Argonne, IL 60439, USA
| | - N Y Morgan
- National Institute of Biomedical Imaging and Bioengineering, NIH, Bethesda, MD, 20892, USA
| | - X Xiao
- X-Ray Science Division, Advanced Photon Source, Argonne National Laboratory Argonne, IL 60439, USA
| | - A A Gomella
- Imaging Physics Lab, Biochemistry and Biophysics Center, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD, 20892, USA
| | - D Mazilu
- Imaging Physics Lab, Biochemistry and Biophysics Center, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD, 20892, USA
| | - E E Bennett
- Imaging Physics Lab, Biochemistry and Biophysics Center, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD, 20892, USA
| | - L Assoufid
- X-Ray Science Division, Advanced Photon Source, Argonne National Laboratory Argonne, IL 60439, USA
| | - F de Carlo
- X-Ray Science Division, Advanced Photon Source, Argonne National Laboratory Argonne, IL 60439, USA
| | - H Wen
- Imaging Physics Lab, Biochemistry and Biophysics Center, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD, 20892, USA
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Stutman D, Finkenthal M. Glancing angle Talbot-Lau grating interferometers for phase contrast imaging at high x-ray energy. APPLIED PHYSICS LETTERS 2012; 101:91108. [PMID: 23024376 PMCID: PMC3443112 DOI: 10.1063/1.4748882] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2012] [Accepted: 08/16/2012] [Indexed: 06/01/2023]
Abstract
A Talbot-Lau interferometer is demonstrated using micro-periodic gratings inclined at a glancing angle along the light propagation direction. Due to the increase in the effective thickness of the absorption gratings, the device enables differential phase contrast imaging at high x-ray energy, with improved fringe visibility (contrast). For instance, at 28° glancing angle, we obtain up to ∼35% overall interferometer contrast with a spectrum having ∼43 keV mean energy, suitable for medical applications. In addition, glancing angle interferometers could provide high contrast at energies above 100 keV, enabling industrial and security applications of phase contrast imaging.
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Affiliation(s)
- D Stutman
- Department of Physics and Astronomy, Johns Hopkins University, Baltimore, Maryland 21218, USA
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