The Observation of NBC Precipitates In Steels In The Nanometer Range Using A Field Emission Gun Scanning Electron Microscope

1997 ◽  
Vol 3 (S2) ◽  
pp. 1243-1244 ◽  
Author(s):  
Raynald Gauvin ◽  
Steve Yue
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Field Emission ◽  
Incident Electron Energy ◽  
Beam Diameter ◽  
Probe Diameter ◽  
Transmission Electron ◽  
Electron Microscopes ◽  
Scanning Electron Microscopes ◽  
Scanning Electron

The observation of microstructural features smaller than 300 nm is generally performed using Transmission Electron Microscopy (TEM) because conventional Scanning Electron Microscopes (SEM) do not have the resolution to image such small phases. Since the early 1990’s, a new generation of microscopes is now available on the market. These are the Field Emission Gun Scanning Electron Microscope with a virtual secondary electron detector. The field emission gun gives a higher brightness than those obtained using conventional electron filaments allowing enough electrons to be collected to operate the microscope with incident electron energy, E0, below 5 keV with probe diameter smaller than 5 nm. At 1 keV, the electron range is 60 nm in aluminum and 10 nm in iron (computed using the CASINO program). Since the electron beam diameter is smaller than 5 nm at 1 keV, the resolution of these microscopes becomes closer to that of TEM.

Resolution of a Transmitted Electron Image Formed by A Scanning Electron Microscope

1970 ◽  
Vol 28 ◽  
pp. 386-387
Author(s):  
S. Takashima ◽  
H. Hashimoto ◽  
S. Kimoto
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Chromatic Aberration ◽  
Objective Lens ◽  
Specimen Thickness ◽  
Probe Diameter ◽  
Transmission Electron ◽  
Electron Image ◽  
Conventional Transmission Electron Microscope ◽  
Scanning Electron

The resolution of a conventional transmission electron microscope (TEM) deteriorates as the specimen thickness increases, because chromatic aberration of the objective lens is caused by the energy loss of electrons). In the case of a scanning electron microscope (SEM), chromatic aberration does not exist as the restrictive factor for the resolution of the transmitted electron image, for the SEM has no imageforming lens. It is not sure, however, that the equal resolution to the probe diameter can be obtained in the case of a thick specimen. To study the relation between the specimen thickness and the resolution of the trans-mitted electron image obtained by the SEM, the following experiment was carried out.

scholarly journals Ultrastructure of cleistothecia and the stages of life cycle of Microsphaera palczewskii by scanning electron microscope

2014 ◽  
Vol 32 (2) ◽  
pp. 275-278
Author(s):  
Joanna Z. Kadłubowska ◽  
Ewa Kalinowska-Kucharska
Keyword(s):  
Electron Microscope ◽  
Life Cycle ◽  
Scanning Electron Microscope ◽  
Scanning Microscopy ◽  
Developmental Cycle ◽  
Central Poland ◽  
Caragana Arborescens ◽  
Electron Microscopes ◽  
Scanning Electron Microscopes ◽  
Scanning Electron

Several year long investigations of the developmental cycle of <i>Microsphaera palczewskii</i> occurring on the leaves of <i>Caragana arborescens</i> in Central Poland are reported. The material was studied with light and scanning electron microscopes. The scanning microscopy micrographs of the clistothecia and appendages presented in this report are the first micrographs of this species.

scholarly journals Scanning electron microscope fine tuning using four-bar piezoelectric actuated mechanism

2018 ◽  
Vol 69 (1) ◽  
pp. 24-31
Author(s):  
Khaled S. Hatamleh ◽  
Qais A. Khasawneh ◽  
Adnan Al-Ghasem ◽  
Mohammad A. Jaradat ◽  
Laith Sawaqed ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Inverse Kinematic ◽  
Fine Tuning ◽  
Electron Microscopes ◽  
Tuning Strategy ◽  
Scanning Electron Microscopes ◽  
Fine Tune ◽  
Kinematic Solution ◽  
Scanning Electron

Abstract Scanning Electron Microscopes are extensively used for accurate micro/nano images exploring. Several strategies have been proposed to fine tune those microscopes in the past few years. This work presents a new fine tuning strategy of a scanning electron microscope sample table using four bar piezoelectric actuated mechanisms. The introduced paper presents an algorithm to find all possible inverse kinematics solutions of the proposed mechanism. In addition, another algorithm is presented to search for the optimal inverse kinematic solution. Both algorithms are used simultaneously by means of a simulation study to fine tune a scanning electron microscope sample table through a pre-specified circular or linear path of motion. Results of the study shows that, proposed algorithms were able to minimize the power required to drive the piezoelectric actuated mechanism by a ratio of 97.5% for all simulated paths of motion when compared to general non-optimized solution.

The Morphology of Obliterative Arterial Diseases in Statu Nascendi

1979 ◽  
Author(s):  
M. Marshall ◽  
J. Staubesand ◽  
H. Hese
Keyword(s):  
Risk Factors ◽  
Electron Microscope ◽  
Blood Platelet ◽  
Arterial Disease ◽  
Transmission Electron ◽  
Electron Microscopes ◽  
Scanning Electron Microscopes ◽  
Mini Pigs ◽  
Scanning Electron ◽  
Blood Platelet Aggregation

The arteries of mini pigs which had been exposed to the local or systemic action of recognised ‘risk factors’ for arterial disease were examined with the light microscope, and the transmission and scanning electron microscopes. Initially the scanning instrument revealed adhesions of platelets in different stages of development, but showed an apparently intact endothelium. With the transmission electron microscope, however, degenerative changes in the endothelium could be observed. Increased blood platelet aggregation was also present. After a few weeks we could see a remarkable focal thickening of the intima, together with deposits on the endothelium of platelets, erythrocytes and fibrin (“mixed microparietal thrombosis”). After 6 months fully developed arteriosclerosis of the abdominal aorta had appeared.

Choosing a Scanning Electron Microscope

1998 ◽  
Vol 4 (S2) ◽  
pp. 896-897
Author(s):  
W. A. Lambe ◽  
P.M. Brady
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Selection Process ◽  
The Other ◽  
Hard Data ◽  
Methodical Approach ◽  
Electron Microscopes ◽  
Scanning Electron Microscopes ◽  
First Time ◽  
Scanning Electron

The variety of instrumentation available to the researcher today can be overwhelming and confusing. Scanning Electron Microscopes (“SEM's) are no exception, and choosing one can often serve as an exercise in dealing with complexity. First time purchasers are most at risk, being subject to a barrage of information that attempts to sway the purchaser in one direction or the other. As a result, one can sometimes be drawn to the details of the latest “high end” performance parameter, while overlooking the basics. At its worst, the selection process can degrade to one of vague guesswork with little hard data to serve as a compass.By applying a methodical approach to define your individual requirements, carefully designed tests of actual instruments, and discussions with your collaborators, potential and experienced users, one can begin to ensure a successful selection process.

The JSM-890 ultra high resolution Scanning Electron Microscope

1989 ◽  
Vol 47 ◽  
pp. 88-89
Author(s):  
M. Kersker ◽  
C. Nielsen ◽  
H. Otsuji ◽  
T. Miyokawa ◽  
S. Nakagawa
Keyword(s):  
Electron Microscope ◽  
High Resolution ◽  
Scanning Electron Microscope ◽  
Morphological Changes ◽  
High Current Density ◽  
High Signal ◽  
Extensive Experience ◽  
Transmission Electron ◽  
Electron Microscopes ◽  
Scanning Electron

Historically, ultra high spatial resolution electron microscopy has belonged to the transmission electron microscope. Today, however, ultra high resolution scanning electron microscopes are beginning to challenge the transmission microscope for the highest resolution.To accomplish high resolution surface imaging, not only is high resolution required. It is also necessary that the integrity of the specimen be preserved, i.e., that morphological changes to the specimen during observation are prevented. The two major artifacts introduced during observation are contamination and beam damage, both created by the small, high current-density probes necessary for high signal generation in the scanning instrument. The JSM-890 Ultra High Resolution Scanning Microscope provides the highest resolution probe attainable in a dedicated scanning electron microscope and its design also accounts for the problematical artifacts described above.Extensive experience with scanning transmission electron microscopes lead to the design considerations of the ultra high resolution JSM- 890.

Considerations in Making Stereo Micrographs With the Scanning Electron Microscope

1973 ◽  
Vol 31 ◽  
pp. 234-235
Author(s):  
E. R. Walter
Keyword(s):  
Fine Structure ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Three Dimensional ◽  
Spatial Relationships ◽  
Additional Information ◽  
Electron Microscopes ◽  
Scanning Electron Microscopes ◽  
Scanning Electron

The information obtainable with the scanning electron microscope can often be increased severalfold through the use of stereomicrograph pairs. Not only is the detail which can be observed the equivalent of a 2X increase in magnification over that apparent in a single micrograph, but, threedimensional spatial relationships are more accurately preserved. This is especially true where protruding or pyramided fine structure and/or gross reentrance exists. Since stereo micrographs are conveniently obtained with most scanning electron microscopes, it is generally desirable to add the additional information they offer whenever the three-dimensional relationships present in the specimen'are not readily apparent.

Field emission scanning electron microscope

1978 ◽  
Vol 36 (1) ◽  
pp. 14-15
Author(s):  
R. Aihara ◽  
S. Saito ◽  
II. Kohinata ◽  
K. Ogura ◽  
H. Otsuji
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Field Emission ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Vacuum System ◽  
Probe Diameter ◽  
Tungsten Single Crystal ◽  
Working Distance ◽  
Scanning Electron

A compact type field emission scanning electron microscope (JSM-F15) has recently been developed (Fig. 1). Moreover, due to the simplicity of the electron optical column and the automatically controlled ultra high vacuum system, a good quality and high resolution image can easily be obtained.The electron optical column, which is shown in Fig. 2, comprises a field emission gun, an electromagnetic lens, scanning coils, etc. The gun, which is composed of a field emitter, a wehnelt and an anode, is pre-aligned. The accelerating voltage is 15 kV and the emitter tip, made of tungsten single crystal, has a [310] orientation in the electron optical axis. The wehnelt is biased through a feedback circuit so as to maintain the emission current constant without varying the accelerating voltage.The electron probe current at the specimen surface is about 3 × 10-11 amp and the probe diameter is about 30Å at the working distance of 15 mm.

Interfacing a Personal Computer to an Analog Scanning Electron Microscope for Storing Images on Optical Disks

1990 ◽  
Vol 48 (2) ◽  
pp. 84-85
Author(s):  
Mark H. Ransick ◽  
Chadwick D. Barklay
Keyword(s):  
Image Analysis ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Low Cost ◽  
Hard Copy ◽  
Analog To Digital ◽  
Optical Disks ◽  
Electron Microscopes ◽  
Scanning Electron Microscopes ◽  
Scanning Electron

Most manufacturers of scanning electron microscopes (SEM) now offer models that display an image digitally. This holds many advantages, including the ability to store the image on a disk and perform image analysis on the sample. Most SEMs in service, however, produce only an analog video output; they do not have the ability to digitize the image. Film is the only method of storing images.Consequentially, film is a significant portion of every microscopy laboratory’s budget. Completely eliminating the use of film from use is not practical. There will always be the need to examine a hard copy of the image; many programs require duplicate copies of each image generated; and it is sound practice to keep a copy of each image on file. By archiving digital images to an inexpensive media, the amount of film used or the time devoted to processing negatives can be greatly reduced.By using personal computers (PCs)s, with a digitizing board and analog to digital (A/D) board, it is possible to construct a relatively low cost digitizing system for any SEM.

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