Brightness field and luminance distribution of light guiding plate using micro molding

There is great interest in improving the brightness of electron sources and therefore the ability of electron optical instrumentation to probe the properties of materials. Extensive work by Dr. Crew and others has provided extremely high brightness sources for certain kinds of analytical problems but which pose serious difficulties in other problems. These sources cannot survive in conventional system vacuums. If one wishes to gather information from the other signal channels activated by electron beam bombardment it is necessary to provide sufficient current to allow an acceptable signal-to-noise ratio. It is possible through careful design to provide a high brightness field emission source which has the capability of providing high currents as well as high current densities to a specimen. In this paper we describe an electrode to provide long-lived stable current in field emission sources.The source geometry was based upon the results of extensive computer modeling. The design attempted to maximize the total current available at a specimen.

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High spatial resolution x-ray microanalysis of interfaces

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100137793 ◽

1995 ◽

Vol 53 ◽

pp. 284-285

Author(s):

J. R. Michael

Keyword(s):

Spatial Resolution ◽

Electron Probe ◽

Solid Angle ◽

Collection Efficiency ◽

Spatial Scales ◽

Energy Dispersive Spectrometer ◽

X Rays ◽

X Ray ◽

Probe Size ◽

Brightness Field

X-ray microanalysis in the analytical electron microscope (AEM) refers to a technique by which chemical composition can be determined on spatial scales of less than 10 nm. There are many factors that influence the quality of x-ray microanalysis. The minimum probe size with sufficient current for microanalysis that can be generated determines the ultimate spatial resolution of each individual microanalysis. However, it is also necessary to collect efficiently the x-rays generated. Modern high brightness field emission gun equipped AEMs can now generate probes that are less than 1 nm in diameter with high probe currents. Improving the x-ray collection solid angle of the solid state energy dispersive spectrometer (EDS) results in more efficient collection of x-ray generated by the interaction of the electron probe with the specimen, thus reducing the minimum detectability limit. The combination of decreased interaction volume due to smaller electron probe size and the increased collection efficiency due to larger solid angle of x-ray collection should enhance our ability to study interfacial segregation.

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Practical Correction of Three Fold Astigmatism in the Philips CM TEM

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100164556 ◽

1996 ◽

Vol 54 ◽

pp. 418-419

Author(s):

Arno J. Bleeker ◽

Mark H.F. Overwijk ◽

Max T. Otten

Keyword(s):

Optical Properties ◽

Phase Contrast ◽

The Other ◽

Objective Lens ◽

Symmetric Part ◽

A Posteriori ◽

Contrast Transfer Function ◽

High Brightness ◽

Rotationally Symmetric ◽

Brightness Field

With the improvement of the optical properties of the modern TEM objective lenses the point resolution is pushed beyond 0.2 nm. The objective lens of the CM300 UltraTwin combines a Cs of 0. 65 mm with a Cc of 1.4 mm. At 300 kV this results in a point resolution of 0.17 nm. Together with a high-brightness field-emission gun with an energy spread of 0.8 eV the information limit is pushed down to 0.1 nm. The rotationally symmetric part of the phase contrast transfer function (pctf), whose first zero at Scherzer focus determines the point resolution, is mainly determined by the Cs and defocus. Apart from the rotationally symmetric part there is also the non-rotationally symmetric part of the pctf. Here the main contributors are not only two-fold astigmatism and beam tilt but also three-fold astigmatism. The two-fold astigmatism together with the beam tilt can be corrected in a straight-forward way using the coma-free alignment and the objective stigmator. However, this only works well when the coefficient of three-fold astigmatism is negligible compared to the other aberration coefficients. Unfortunately this is not generally the case with the modern high-resolution objective lenses. Measurements done at a CM300 SuperTwin FEG showed a three fold-astigmatism of 1100 nm which is consistent with measurements done by others. A three-fold astigmatism of 1000 nm already sinificantly influences the image at a spatial frequency corresponding to 0.2 nm which is even above the point resolution of the objective lens. In principle it is possible to correct for the three-fold astigmatism a posteriori when through-focus series are taken or when off-axis holography is employed. This is, however not possible for single images. The only possibility is then to correct for the three-fold astigmatism in the microscope by the addition of a hexapole corrector near the objective lens.

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Evaluation of Luminance Distribution by Advertising Lighting Type in Commercial Area of Gwangju

Journal of the Korean Society of Urban Environment ◽

10.33768/ksue.2018.18.1.41 ◽

2018 ◽

Vol 18 (1) ◽

pp. 41-51

Author(s):

Mincheol Cho ◽

◽

Yeonhee Kim ◽

Yoonkook Lee ◽

Jeongwon Jang ◽

...

Keyword(s):

Luminance Distribution ◽

Commercial Area

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FIELD MEASUREMENTS OF ILLUMINANCE AND LUMINANCE DISTRIBUTION

Journal of Environmental Engineering (Transactions of AIJ) ◽

10.3130/aije.85.943 ◽

2020 ◽

Vol 85 (778) ◽

pp. 943-952

Author(s):

Naoko SHINOHARA ◽

Toshie IWATA ◽

Etsuko MOCHIZUKI ◽

Tomoko TANIGUCHI ◽

Koichi KAIHO

Keyword(s):

Field Measurements ◽

Luminance Distribution

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MEASUREMENT OF LUMINANCE AND LUMINANCE DISTRIBUTION BY ORTHOGRAPHIC PROJECTION CAMERA (Part 1)

Transactions of the Architectural Institute of Japan ◽

10.3130/aijsaxx.243.0_73 ◽

1976 ◽

Vol 243 (0) ◽

pp. 73-79 ◽

Cited By ~ 3

Author(s):

HIROSHI NAKAMURA

Keyword(s):

Orthographic Projection ◽

Luminance Distribution

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Method for determining the luminance distribution of electro-optical X-ray image intensifiers

10.3403/00064325 ◽

1982 ◽

Keyword(s):

X Ray ◽

Luminance Distribution ◽

Image Intensifiers

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High-Resolution Scanning Electron Microscopy and Microanalysis of Supported Metal Catalysts

MRS Proceedings ◽

10.1557/proc-589-259 ◽

1999 ◽

Vol 589 ◽

Cited By ~ 1

Author(s):

Jingyue Liu

Keyword(s):

High Resolution ◽

Low Voltage ◽

Supported Catalysts ◽

Metal Catalysts ◽

Supported Metal Catalysts ◽

Surface Sensitivity ◽

Brightness Field ◽

Backscattered Electron ◽

Enhanced Surface ◽

Supported Metal

AbstractThe use of a high-brightness field emission gun and novel secondary electron detection systems makes it possible to acquire nanometer-resolution surface images of bulk materials, even at low electron beam voltages. The advantages of low-voltage SEM include enhanced surface sensitivity, reduced sample charging on non-conducting materials, and significantly reduced electron range and interaction volume. High-resolution images formed by collecting the backscattered electron signal can give information about the size and spatial distribution of metal nanoparticles in supported catalysts. Low-voltage XEDS can provide compositional information of bulk samples with enhanced surface sensitivity and significantly improved spatial resolution. High-resolution SEM techniques enhance our ability to detect and, subsequently, analyze the composition of nanoparticles in supported metal catalysts. Applications of high-resolution SEM imaging and microanalysis techniques to the study of industrial supported catalysts are discussed.

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