Multibeam field emission x-ray system with half-scan reconstruction algorithm

Analytical TEMs have two variations in x-ray detector geometry, high and low angle take off. The high take off angle is advantageous for accuracy of quantitative analysis, because the x rays are less absorbed when they go through the sample. The low take off angle geometry enables better sensitivity because of larger detector solid angle.Hitachi HF-2000 cold field emission TEM has two versions; high angle take off and low angle take off. The former allows an energy dispersive x-ray detector above the objective lens. The latter allows the detector beside the objective lens. The x-ray take off angle is 68° for the high take off angle with the specimen held at right angles to the beam, and 22° for the low angle take off. The solid angle is 0.037 sr for the high angle take off, and 0.12 sr for the low angle take off, using a 30 mm2 detector.

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Nondestructive Inspection of Thin, Low-Z Samples using Multiplexed Compton Scatter Tomography

MRS Proceedings ◽

10.1557/proc-503-297 ◽

1997 ◽

Vol 503 ◽

Cited By ~ 1

Author(s):

B. L. Evans ◽

J. B. Martin ◽

L. W. Burggraf

Keyword(s):

Signal To Noise Ratio ◽

Reconstruction Algorithm ◽

Filtered Backprojection ◽

Line Broadening ◽

Compton Scatter ◽

X Ray ◽

Tomography System ◽

Transmission Computed Tomography ◽

High Purity Germanium ◽

Scattered Energy

ABSTRACTThe viability of a Compton scattering tomography system for nondestructively inspecting thin, low Z samples for corrosion is examined. This technique differs from conventional x-ray backscatter NDI because it does not rely on narrow collimation of source and detectors to examine small volumes in the sample. Instead, photons of a single energy are backscattered from the sample and their scattered energy spectra are measured at multiple detector locations, and these spectra are then used to reconstruct an image of the object. This multiplexed Compton scatter tomography technique interrogates multiple volume elements simultaneously. Thin samples less than 1 cm thick and made of low Z materials are best imaged with gamma rays at or below 100 keV energy. At this energy, Compton line broadening becomes an important resolution limitation. An analytical model has been developed to simulate the signals collected in a demonstration system consisting of an array of planar high-purity germanium detectors. A technique for deconvolving the effects of Compton broadening and detector energy resolution from signals with additive noise is also presented. A filtered backprojection image reconstruction algorithm with similarities to that used in conventional transmission computed tomography is developed. A simulation of a 360–degree inspection gives distortion-free results. In a simulation of a single-sided inspection, a 5 mm × 5 mm corrosion flaw with 50% density is readily identified in 1-cm thick aluminum phantom when the signal to noise ratio in the data exceeds 28.

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Thermoelectric Generator Using Polyaniline-Coated Sb2Se3/β-Cu2Se Flexible Thermoelectric Films

Polymers ◽

10.3390/polym13091518 ◽

2021 ◽

Vol 13 (9) ◽

pp. 1518

Author(s):

Minsu Kim ◽

Dabin Park ◽

Jooheon Kim

Keyword(s):

Electron Microscopy ◽

Electrical Conductivity ◽

Field Emission ◽

Photoelectron Spectroscopy ◽

Thermoelectric Generator ◽

Hydrothermal Reaction ◽

Water Evaporation ◽

Pani Film ◽

Portable Devices ◽

X Ray

Herein, Sb2Se3 and β-Cu2Se nanowires are synthesized via hydrothermal reaction and water evaporation-induced self-assembly methods, respectively. The successful syntheses and morphologies of the Sb2Se3 and β-Cu2Se nanowires are confirmed via X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, field emission scanning electron microscopy (FE-SEM), and field emission transmission electron microscopy (FE-TEM). Sb2Se3 materials have low electrical conductivity which limits application to the thermoelectric generator. To improve the electrical conductivity of the Sb2Se3 and β-Cu2Se nanowires, polyaniline (PANI) is coated onto the surface and confirmed via Fourier-transform infrared spectroscopy (FT-IR), FE-TEM, and XPS analysis. After coating PANI, the electrical conductivities of Sb2Se3/β-Cu2Se/PANI composites were increased. The thermoelectric performance of the flexible Sb2Se3/β-Cu2Se/PANI films is then measured, and the 70%-Sb2Se3/30%-β-Cu2Se/PANI film is shown to provide the highest power factor of 181.61 μW/m·K2 at 473 K. In addition, a thermoelectric generator consisting of five legs of the 70%-Sb2Se3/30%-β-Cu2Se/PANI film is constructed and shown to provide an open-circuit voltage of 7.9 mV and an output power of 80.1 nW at ΔT = 30 K. This study demonstrates that the combination of inorganic thermoelectric materials and flexible polymers can generate power in wearable or portable devices.

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Low-voltage high-curent field emission from a simple pointed graphite emitter tested in a transmission-type X-ray demonstator

2015 28th International Vacuum Nanoelectronics Conference (IVNC) ◽

10.1109/ivnc.2015.7225576 ◽

2015 ◽

Author(s):

J. Klas ◽

D. Lutzenkirchen-Hecht ◽

P. Serbun ◽

G. Muller

Keyword(s):

Field Emission ◽

Low Voltage ◽

X Ray

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Field-Emission Scanning Electron Microscopy and Energy-Dispersive X-Ray Analysis to Understand the Role of Tannin-Based Dyes in the Degradation of Historical Wool Textiles

Microscopy and Microanalysis ◽

10.1017/s1431927614012793 ◽

2014 ◽

Vol 20 (5) ◽

pp. 1534-1543 ◽

Cited By ~ 10

Author(s):

Annalaura Restivo ◽

Ilaria Degano ◽

Erika Ribechini ◽

Josefina Pérez-Arantegui ◽

Maria Perla Colombini

Keyword(s):

Electron Microscopy ◽

Scanning Electron Microscopy ◽

Elemental Composition ◽

Field Emission ◽

Cross Sections ◽

Morphological Changes ◽

Energy Dispersive ◽

X Ray ◽

Edx Analysis ◽

Scanning Electron

Abstract:An innovative approach, combining field-emission scanning electron microscopy (FESEM) with energy dispersive X-ray spectroscopy (EDX) analysis, is presented to investigate the degradation mechanisms affecting tannin-dyed wool. In fact, tannin-dyed textiles are more sensitive to degradation then those dyed with other dyestuffs, even in the same conservation conditions.FESEM-EDX was first used to study a set of 48 wool specimens (artificially aged) dyed with several raw materials and mordants, and prepared according to historical dyeing recipes. EDX analysis was performed on the surface of wool threads and on their cross-sections. In addition, in order to validate the model formulated by the analysis of reference materials, several samples collected from historical and archaeological textiles were subjected to FESEM-EDX analysis.FESEM-EDX investigations enabled us to reveal the correlation between elemental composition and morphological changes. In addition, aging processes were clarified by studying changes in the elemental composition of wool from the protective cuticle to the fiber core in cross-sections. Morphological and elemental analysis of wool specimens and of archaeological and historical textiles showed that the presence of tannins increases wool damage, primarily by causing a sulfur decrease and fiber oxidation.

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Three-dimensional focal stack imaging in scanning transmission X-ray microscopy with an improved reconstruction algorithm

Optics Express ◽

10.1364/oe.27.007787 ◽

2019 ◽

Vol 27 (5) ◽

pp. 7787 ◽

Cited By ~ 3

Author(s):

Limei Ma ◽

Xiangzhi Zhang ◽

Zijian Xu ◽

Andreas Späth ◽

Zhenjiang Xing ◽

...

Keyword(s):

Three Dimensional ◽

Reconstruction Algorithm ◽

X Ray ◽

Scanning Transmission ◽

Focal Stack

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Comparison of methods for sensitivity correction in Talbot–Lau computed tomography

International Journal of Computer Assisted Radiology and Surgery ◽

10.1007/s11548-021-02487-x ◽

2021 ◽

Author(s):

Lina Felsner ◽

Philipp Roser ◽

Andreas Maier ◽

Christian Riess

Keyword(s):

Iterative Reconstruction ◽

Phase Contrast ◽

Reconstruction Algorithm ◽

General Purpose ◽

Contrast Imaging ◽

X Ray ◽

Iterative Reconstruction Algorithm ◽

Inhomogeneous Phase ◽

The Cost ◽

Residual Errors

Abstract Purpose In Talbot–Lau X-ray phase contrast imaging, the measured phase value depends on the position of the object in the measurement setup. When imaging large objects, this may lead to inhomogeneous phase contributions within the object. These inhomogeneities introduce artifacts in tomographic reconstructions of the object. Methods In this work, we compare recently proposed approaches to correct such reconstruction artifacts. We compare an iterative reconstruction algorithm, a known operator network and a U-net. The methods are qualitatively and quantitatively compared on the Shepp–Logan phantom and on the anatomy of a human abdomen. We also perform a dedicated experiment on the noise behavior of the methods. Results All methods were able to reduce the specific artifacts in the reconstructions for the simulated and virtual real anatomy data. The results show method-specific residual errors that are indicative for the inherently different correction approaches. While all methods were able to correct the artifacts, we report a different noise behavior. Conclusion The iterative reconstruction performs very well, but at the cost of a high runtime. The known operator network shows consistently a very competitive performance. The U-net performs slightly worse, but has the benefit that it is a general-purpose network that does not require special application knowledge.

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