scholarly journals Confocal soft X-ray scanning transmission microscopy: setup, alignment procedure and limitations

2015 ◽  
Vol 22 (1) ◽  
pp. 113-118 ◽  
Author(s):  
Andreas Späth ◽  
Jörg Raabe ◽  
Rainer H. Fink
Keyword(s):  
Magnetic Thin Films ◽  
Biological Tissues ◽  
Polymer Materials ◽  
Zone Plate ◽  
Contrast Imaging ◽  
Transmission Microscopy ◽  
X Ray ◽  
Alignment Procedure ◽  
High Contrast Imaging ◽  
Scanning Transmission

Zone-plate-based scanning transmission soft X-ray microspectroscopy (STXM) is a well established technique for high-contrast imaging of sufficiently transparent specimens (e.g.ultrathin biological tissues, polymer materials, archaeometric specimens or magnetic thin films) with spatial resolutions in the regime of 20 nm and high spectroscopic or chemical sensitivity. However, due to the relatively large depth of focus of zone plates, the resolution of STXM along the optical axis so far stays unambiguously behind for thicker X-ray transparent specimens. This challenge can be addressed by the implementation of a second zone plate in the detection pathway of the beam, resulting in a confocal arrangement. Within this paper a first proof-of-principle study for a confocal STXM (cSTXM) and an elaborate alignment procedure in transmission and fluorescence geometry are presented. Based on first confocal soft X-ray micrographs of well known specimens, the advantage and limitation of cSTXM as well as further development potentials for future applications are discussed.

The CM120 Biotwin: a high-contrast objective lens, optimum cryo-vacuum and improved EDX performance

1995 ◽  
Vol 53 ◽  
pp. 584-585
Author(s):  
Uwe Lücken ◽  
Michael Felsmann ◽  
Wim M. Busing ◽  
Frank de Jong
Keyword(s):  
Life Science ◽  
Focal Length ◽  
Objective Lens ◽  
High Contrast ◽  
Contrast Imaging ◽  
X Ray ◽  
Forming Mechanism ◽  
Similar Image ◽  
High Contrast Imaging ◽  
Low Concentrations

A new microscope for the study of life science specimen has been developed. Special attention has been given to the problems of unstained samples, cryo-specimens and x-ray analysis at low concentrations.A new objective lens with a Cs of 6.2 mm and a focal length of 5.9 mm for high-contrast imaging has been developed. The contrast of a TWIN lens (f = 2.8 mm, Cs = 2 mm) and the BioTWTN are compared at the level of mean and SD of slow scan CCD images. Figure 1a shows 500 +/- 150 and Fig. 1b only 500 +/- 40 counts/pixel. The contrast-forming mechanism for amplitude contrast is dependent on the wavelength, the objective aperture and the focal length. For similar image conditions (same voltage, same objective aperture) the BioTWIN shows more than double the contrast of the TWIN lens. For phasecontrast specimens (like thin frozen-hydrated films) the contrast at Scherzer focus is approximately proportional to the √ Cs.

Aberration-Corrected X-Ray Spectrum Imaging and Fresnel Contrast to Differentiate Nanoclusters and Cavities in Helium-Irradiated Alloy 14YWT

2014 ◽  
Vol 20 (2) ◽  
pp. 613-626 ◽  
Author(s):  
Chad M. Parish ◽  
Michael K. Miller
Keyword(s):  
Collection Efficiency ◽  
Structural Materials ◽  
Fusion Reactors ◽  
Contrast Imaging ◽  
Multivariate Statistical ◽  
X Ray ◽  
Scanning Transmission ◽  
Helium Embrittlement ◽  
Materials Used ◽  
Aberration Corrected

AbstractHelium accumulation negatively impacts structural materials used in neutron-irradiated environments, such as fission and fusion reactors. Next-generation fission and fusion reactors will require structural materials, such as steels, that are resistant to large neutron doses yet see service temperatures in the range most affected by helium embrittlement. Previous work has indicated the difficulty of experimentally differentiating nanometer-sized cavities such as helium bubbles from the Ti–Y–O rich nanoclusters (NCs) in radiation-tolerant nanostructured ferritic alloys (NFAs). Because the NCs are expected to sequester helium away from grain boundaries and reduce embrittlement, experimental methods to study simultaneously the NC and bubble populations are needed. In this study, aberration-corrected scanning transmission electron microscopy (STEM) results combining high-collection-efficiency X-ray spectrum images (SIs), multivariate statistical analysis (MVSA), and Fresnel-contrast bright-field STEM imaging, have been used for such a purpose. Fresnel-contrast imaging, with careful attention to TEM-STEM reciprocity, differentiates bubbles from NCs. MVSA of X-ray SIs unambiguously identifies NCs. Therefore, combined Fresnel-contrast STEM and X-ray SI is an effective STEM-based method to characterize helium-bearing NFAs.

Radiography of Soft Tissue of the Foot and Ankle with Diffraction Enhanced Imaging

2004 ◽  
Vol 94 (3) ◽  
pp. 315-322 ◽  
Author(s):  
Jun Li ◽  
Zhong Zhong ◽  
Roy Lidtke ◽  
Klaus E. Kuettner ◽  
Charles Peterfy ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Soft Tissues ◽  
Foot And Ankle ◽  
Contrast Imaging ◽  
X Ray ◽  
Human Foot ◽  
Diffraction Enhanced Imaging ◽  
High Contrast Imaging ◽  
X Ray Imaging ◽  
Calcified Tissues

Non-calcified tissues, including tendons, ligaments, adipose tissue and cartilage, are not visible, for any practical purposes, with conventional X-ray imaging. Therefore, any pathological changes in these tissues generally necessitate detection through magnetic resonance imaging or ultrasound technology. Until recently the development of an X-ray imaging technique that could detect both bone and soft tissues seemed unrealistic. However, the introduction of diffraction enhanced X-ray imaging (DEI) which is capable of rendering images with absorption, refraction and scatter rejection qualities has allowed detection of specific soft tissues based on small differences in tissue densities. Here we show for the first time that DEI allows high contrast imaging of soft tissues, including ligaments, tendons and adipose tissue, of the human foot and ankle. (J Am Podiatr Med Assoc 94(3): 315–322, 2004)

Quantitative Chemical Speciation of Multi-Phase Polymers Using Zone Plate x-ray Microscopy

1998 ◽  
Vol 4 (S2) ◽  
pp. 808-809
Author(s):  
A.P. Hitchcock ◽  
S.G. Urquhart ◽  
H. Ade ◽  
E.G. Rightor ◽  
W. Lidy
Keyword(s):  
Chemical Analysis ◽  
Spatial Resolution ◽  
Phase Segregation ◽  
Zone Plate ◽  
Quantitative Chemical Analysis ◽  
X Ray ◽  
Scanning Transmission ◽  
Complex Polymers ◽  
Multi Phase ◽  
Quantitative Chemical

Phase segregation is important in determining the properties of many complex polymers, including polyurethanes. Achieving a better understanding of the links between formulation, chemical nature of segregated phases, and physical properties, has the potential to aid development of improved polymers. However, the sub-micron size of segregated features precludes detailed chemical analysis by most existing methods. Zone-plate based, scanning transmission X-ray microscopes (STXM) at NSLS and ALS provide quantitative chemical analysis (speciation) of segregated polymer phases at ∼50 nm spatial resolution. Image sequences acquire much more data with less radiation damage, than spot spectra. After alignment, they provide high quality near edge spectra, and thus quantitative analysis, at full spatial resolution.Fig. 1 shows an image and spectra acquired with the NSLS STXM of a macro-phase segregated TDI polyurethane. Spectral decomposition using model polymer spectra is used to measure the local urea, urethane and polyether content.

The Research of Cancer Imaging by X-Ray In-Line Phase Contrast Imaging Technique

2013 ◽  
Vol 718-720 ◽  
pp. 2099-2102
Author(s):  
Qiang Tao ◽  
Shu Qian Luo
Keyword(s):  
Nude Mice ◽  
Phase Contrast ◽  
Soft Tissues ◽  
Ccd Camera ◽  
Biological Tissues ◽  
Image Resolution ◽  
Phase Contrast Imaging ◽  
Contrast Imaging ◽  
Noninvasive Technique ◽  
X Ray

The hard X-ray in-line phase contrast imaging (HXILPCI) is a phase contrast technique that generates excellent contrast of biological soft tissues compared to conventional X-ray absorption radiography. We explore the application of HXILPCI in the diagnosis of gastric cancer and pancreatic cancer. These nude mice cancer samples were checked by HXILPCI to obtain projection contrast images of 9μm image resolution with CCD camera. The texture extraction was based on gray level co-occurrence matrix (GLCM). The corresponding morphological features of abnormal and normal tissues are analyzed. The produced phase contrast images of nude mice cancer samples show clearly biological tissues architectures and the size of cancer. The paper results show that HXILPCI can be a potential noninvasive technique to diagnose early cancer.

scholarly journals Soft X-ray Scanning Transmission Microscopy Studies of Radiation Damage by Electron, Ion and X-ray Beams

2020 ◽  
Vol 26 (S2) ◽  
pp. 2072-2074
Author(s):  
Adam Hitchcock ◽  
Hao Yuan ◽  
Lis Melo ◽  
Nabil Basim
Keyword(s):  
Radiation Damage ◽  
Transmission Microscopy ◽  
X Ray ◽  
Scanning Transmission

Ratio-contrast imaging of dual-energy absorption for element mapping with a scanning transmission X-ray microscope

2010 ◽  
Vol 17 (6) ◽  
pp. 804-809 ◽  
Author(s):  
X. Z. Zhang ◽  
Z. J. Xu ◽  
R. Z. Tai ◽  
X. J. Zhen ◽  
Y. Wang ◽  
...  
Keyword(s):  
Energy Absorption ◽  
Dual Energy ◽  
Contrast Imaging ◽  
X Ray ◽  
Scanning Transmission ◽  
Element Mapping

Structural and Optical Properties of Group III-Nitride Quantum Wells Studied by (S)Tem and CL

1997 ◽  
Vol 482 ◽  
Author(s):  
H. Lakner ◽  
Q. Liu ◽  
G. Brockt ◽  
A. Radefeld ◽  
F. Schulze-Kraasch ◽  
...  
Keyword(s):  
Optical Properties ◽  
High Resolution ◽  
Quantum Wells ◽  
Structural Defects ◽  
Chemical Compositions ◽  
Contrast Imaging ◽  
X Ray ◽  
Group Iii ◽  
Scanning Transmission ◽  
Convergent Beam

AbstractWurtzite InGaN/GaN and AlGaN/GaN heterostructures grown on sapphire by metal organic vapor phase epitaxy were studied using scanning transmission electron microscopy (STEM), cathodoluminescence (CL) combined with secondary electron (SE) imaging, high resolution x-ray diffractometry (HRXRD), and atomic force microscopy (AFM).SE imaging and AFM were used to study the surface morphology. The results indicate the presence of the following structural defects on the surface of InGaN/GaN heterostructures: hexagonal mesa-like structures, hexagonal pyramids and micropipes, while the surface of the AlGaN/GaN heterostructures are mirror-like smooth. The local optical properties of defects and defect free regions were studied using spatially resolved CL at low temperature. In addition, the dependence of the optical properties of both sorts of heterostructures on the quantum well width or chemical composition of ternary materials was investigated. The structural properties of the heterostructures were studied by STEM and HRXRD. Convergent beam electron diffraction (CBED) and corresponding simulations, convergent beam imaging (CBIM), and high resolution x-ray diffraction (HRXRD) were used to study the strained layers. Dislocations and interface properties were characterized using bright-field imaging, while the chemical compositions fluctuations were analyzed by Z-contrast imaging and energy dispersive x-ray microanalysis (EDX).

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