Effect of energy filtering on micro-diffraction in the SEM

1994 ◽  
Vol 52 ◽  
pp. 604-605
Author(s):  
James F. Mancuso ◽  
Leo A. Fama ◽  
William B. Maxwell ◽  
Jerry L. Lehman ◽  
Hasso Weiland ◽  
...  
Keyword(s):  
Detection Efficiency ◽  
Ccd Camera ◽  
High Gain ◽  
Microchannel Plate ◽  
Electrostatic Energy ◽  
Energy Filtering ◽  
Electron Channelling ◽  
Low Energy Electrons ◽  
Low Sensitivity ◽  
Angular Field Of View

Micro-diffraction based crystallography is essential to the design and development of many classes of ‘crafted materials’. Although the scanning electron microscope can provide crystallographic information with high spatial resolution, its current utility is severely limited by the low sensitivity of existing diffraction techniques (ref: Dingley). Previously, Joy showed that energy filtering increased contrast and pattern visibility in electron channelling. This present paper discribes the effect of energy filtering on EBSP sensitivity and backscattered SEM imaging.The EBSP detector consisted of an electron energy filter, a microchannel plate detector, a phosphor screen, optical coupler, and a slow scan CCD camera. The electrostatic energy filter used in this experiment was constructed as a cone with 5 coaxial electrodes. The angular field-of-view of the filter was approximately 38°. The microchannel plate, which was the initial sensing component, had high gain and had 50% to 80% detection efficiency for the low energy electrons that passed through the retarding field filter.

Characterization of the low accelerating voltage performance of a microchannel plate based detector system for scanning microscopy

1991 ◽  
Vol 49 ◽  
pp. 364-365
Author(s):  
Raymond F. Cochran
Keyword(s):  
Detection Efficiency ◽  
Direct Analysis ◽  
Microchannel Plate ◽  
Axis Orientation ◽  
Backscattered Electrons ◽  
Low Energy Electrons ◽  
High Detection Efficiency ◽  
Voltage Performance ◽  
Beam Currents

The Galileo SEM2000 microchannel plate (MCP) detector collects onaxis symmetrical secondary electron images at accelerating voltages as low as 200 eV and beam currents less than 5 picoamps. Symmetrical images are particularly useful in metrology and for viewing features that are shielded by topology from an off-axis detector. Backscatter images from the same on-axis orientation can be obtained at accelerating voltages below 500 eV and beam currents less than 10 picoamps.The ability to image secondary and backscattered electrons in the same orientation, together with extremely high detection efficiency for low energy electrons make it a valuable tool for direct analysis of beam-sensitive or dielectric samples. Additional topographic enhancement can be obtained by A-B signal processing at accelerating voltages as low as 200 eV.

High detection efficiency neutron sensitive microchannel plate

2013 ◽  
Vol 8 (01) ◽  
pp. P01015-P01015 ◽  
Author(s):  
J Pan ◽  
Y Yang ◽  
Y Tian ◽  
M Zeng ◽  
T Deng ◽  
...  
Keyword(s):  
Detection Efficiency ◽  
Microchannel Plate ◽  
High Detection ◽  
High Detection Efficiency

Quantum detection efficiency of spherical microchannel plate in extreme ultraviolet

2011 ◽  
Vol 19 (11) ◽  
pp. 2596-2602
Author(s):  
尼启良 NI Qi-liang ◽  
韩素立 HAN Su-li ◽  
陈斌 CHEN Bin ◽  
王海峰 WANG Hai-feng
Keyword(s):  
Extreme Ultraviolet ◽  
Detection Efficiency ◽  
Microchannel Plate ◽  
Quantum Detection

Studies of Prototype High-Gain Microchannel Plate Photomultiliers

1979 ◽  
Vol 26 (1) ◽  
pp. 388-394 ◽  
Author(s):  
C. C. Lo ◽  
Branko Leskovar
Keyword(s):  
High Gain ◽  
Microchannel Plate

The External Thread Detection of Liquefied Gas Valve Based on Image Processing Technology

2013 ◽  
Vol 658 ◽  
pp. 551-554
Author(s):  
Xiao Dong Wang ◽  
Bo Liu ◽  
Xiao Wei Chen ◽  
Wei Zhang ◽  
Zhi Gang Guo
Keyword(s):  
Image Processing ◽  
Detection Efficiency ◽  
Ccd Camera ◽  
Contact Detection ◽  
Standard Size ◽  
External Thread ◽  
Thread Profile ◽  
Processing Techniques ◽  
Liquefied Gas

For liquefied gas valve external thread detections, the gauges traditional external thread detection. Although this method simply, easy to operate, but the detection process in contact with the thread and thus cannot guarantee the quality of the thread and the low detection efficiency. The external thread detection of liquefied gas valve based on image processing techniques adopts a non-contact detection. CCD camera collects image of the external thread and transmitted to the computer by the acquisition board. Thus image preprocessing, image segmentation and then get the thread edge contour. Finally, Matched thread profile .By comparing with the standard size tape to determine eligibility. The experimental results show that this method is feasible.

Counting Single DNA Molecules in a Capillary with Radial Focusing

2003 ◽  
Vol 56 (3) ◽  
pp. 149 ◽  
Author(s):  
Jinjian Zheng ◽  
Edward S. Yeung
Keyword(s):  
Single Molecule ◽  
Detection Efficiency ◽  
Signal To Noise Ratio ◽  
Sampling Rate ◽  
Ccd Camera ◽  
Counting Efficiency ◽  
Spherical Particles ◽  
Dna Molecules ◽  
Single Dna Molecules ◽  
Relative Standard

For single-molecule detection, usually a small detection volume of 10 pL or less is used to improve the signal-to-noise ratio. Detection of every molecule in a sample requires that the sample be driven through a well-defined volume to facilitate laser excitation. We report a novel approach to count single DNA molecules with nearly 100% efficiency. By applying an electric field across a 40 cm long, 75 × 75 µm2 square capillary together with hydrodynamic flow from cathode to anode, we were able to concentrate more than 95% of DNA molecules into a 10 µm region at the centre of the capillary. The YOYO-1 labelled λ-DNA molecules were imaged with an intensified CCD camera. We found that the single DNA molecule detection efficiency in a 10–17 M solution was 114 ± 21%. The mobility of the DNA molecules after radial focusing was relatively constant, with relative standard deviations ranging from 0.8% to 1.4%. This allowed us to match the sampling rate to the length of the detection window to maximize counting efficiency. Analysis of a 40.2 nL injected plug of 2 × 10–14 M λ-DNA gave a result of 492 ± 73 molecules, which agreed well with the estimated value of 484. This method should be generally useful for counting deformable molecules or non-spherical particles at extremely low concentrations.

Electron optical design of an EFTEM concerning optimum selection of imaging parameters for different sizes of detection systems

1995 ◽  
Vol 53 ◽  
pp. 308-309
Author(s):  
G. Benner ◽  
W. Probst ◽  
R. Rilk
Keyword(s):  
Detection System ◽  
Photographic Plate ◽  
Optical Design ◽  
Ccd Camera ◽  
Energy Window ◽  
Acceptance Angle ◽  
Detection Systems ◽  
Energy Filtering ◽  
Transmission Electron ◽  
Specimen Area

The amount of information which can be gained about an object is considerably improved by the incorporation of an imaging energy filter in a TEM. Besides the conventional modes of operation elastic brightfield (EBF) and darkfield (EDF) imaging or diffraction are provided by an Energy Filtering Transmission Electron Microscope (EFTEM) as well as Electron Spectroscopic Imaging (ESI) or Electron Energy Loss Spectroscopy (EELS). Thus, the demands for carefully designed highly flexible electron optics are much more sophisticated as compared to a CTEM.One of the most important parameters for elastic imaging and ESI is the width of the energy window, which can be selected by a slit aperture of adjustable width according to the particular needs. This energy window defines the size of the transferable specimen area or diffraction pattern, respectively, as well as the acceptance angle of the spectrometer. In order to meet the optimum parameters concerning the energy window and the size of the detection system (e.g. photographic plate, image plate, Slow Scan CCD camera (SSCCD), TV camera, electron detector, etc.) the magnifications of the pre- and of the post-spectrometer projector lens systems has to be independently adjustable.

An Integrated Energy-Filtering TEM for The Life Sciences

1996 ◽  
Vol 54 ◽  
pp. 466-467
Author(s):  
A.F. de Jong ◽  
H. Coppoolse ◽  
U. Lücken ◽  
M.K. Kundmann ◽  
A.J. Gubbens ◽  
...  
Keyword(s):  
Low Dose ◽  
Life Sciences ◽  
Ccd Camera ◽  
Cold Trap ◽  
Objective Lens ◽  
Elemental Mapping ◽  
Energy Filtering ◽  
Transmission Electron ◽  
Computer Controlled ◽  
High Degree

Energy-filtered transmission electron microscopy (EFTEM) has many uses in life sciences1. These include improved contrast for imaging unstained, cryo or thick samples; improved diffraction for electron crystallography, and elemental mapping and analysis. We have developed a new system for biological EFTEM that combines advanced electron-optical performance with a high degree of automation. The system is based on the Philips CM series of microscopes and the Gatan post-column imaging filter (GIF). One combination particulary suited for the life sciences is that of the CM 120-BioTWIN and the GIF100: the CM120-BioFilter. The CM 120-BioTWIN is equipped with a high-contrast objective lens for biological samples. Its specially designed cold-trap, together with low-dose software, supports full cryo-microscopy. The GIF 100 is corrected for second-order aberrations in both images and spectra. It produces images that are isochromatic to within 1.5 eV at 120 keV and distorted by less than 2% over lk x lk pixels. All the elements of the filter are computer controlled. Images and spectra are detected by a TV camera or a multi-scan CCD camera, both of which are incorporated in the filter. All filter and camera functions are controlled from Digital Micrograph running on an Apple Power Macintosh.

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