The Use of a Lanthanum Hexaboride Filament in a Transmission Electron Microscope - The Philips EM-400

1977 ◽  
Vol 35 ◽  
pp. 64-65 ◽  
Author(s):  
V. R. Mumaw ◽  
B. L. Munger
Keyword(s):  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Lanthanum Hexaboride ◽  
Electron Source ◽  
Transmission Electron ◽  
Electron Microscopes ◽  
Scanning Electron Microscopes ◽  
Scanning Electron

The use of lanthanum hexaboride (LaBg) as an electron source in scanning electron microscopes equipped with an ion pumped emission chamber at less than 10~6 torr, has proven to be very advantageous. It was not until the introduction of the Philips EM-400 that a standard commercially available transmission electron microscope was differentially pumped between the emission chamber and the viewing chamber and capable of achieving a vacuum suitable for utilizing this type of electron source.Only minor modifications were necessary to use the LaBg filament (Kimbal Physics, Wilton, N.H.) in the Philips EM-400 electron microscope. The Wehnelt cap was modified so that the Wehnelt aperture can be removed without disassembly of the cap (Fig. 1). The Wehnelt aperture is 0.7 mm in diameter. A simple spanner wrench is used to remove the Wehnelt aperture. Rough centering of the filament was quite easy using a Zeiss operating stereomicroscope at 25X with the Wehnelt aperture removed.

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.

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.

Ultrastructure Research of the Gastritis from Returning Bile

1990 ◽  
Vol 48 (3) ◽  
pp. 202-203
Author(s):  
Shaopeng Hu ◽  
Jianhua Wang ◽  
Zhen Li ◽  
Huei Chen ◽  
Fei Cu ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Gastric Mucosa ◽  
Scanning Electron Microscope ◽  
Lamina Propria ◽  
Transmission Electron Microscope ◽  
Ultrastructural Change ◽  
Common Disease ◽  
Epithelial Surface ◽  
Transmission Electron ◽  
Scanning Electron

Gastritis from returning bile is a common disease, but the reason for the disease is not clear. As the pathologic ultrastructure research progresses, it has drawn attention to the ultrastructural change of cells in gastric mucosa by clinical workers. We observed gastric mucosa tissues of 15 patients suffering from gastritis with a transmission electron microscope (TEM) and a scanning electron microscope (SEM). It is the first report in China that fungus exists in the lamina propria of gastric mucosa tissue. The result is as follows.The gastric mucosa tissues of 15 patients suffering from gastritis were acquired by stomachoscopy. Both TEM and SEM specimens were prepared by the usual methods. Under the TEM, the epithelial surface became higher and larger. Mitochondria of the cells were swollen and cristae were disrupted. There were vacuoles in the cells. The nucleus showed disorder, heterochromatin became darker, and nucleolae could be observed.

Remote On-Line Control of a High-Voltage in situ Transmission Electron Microscope with A Rational User Interface

1996 ◽  
Vol 54 ◽  
pp. 384-385
Author(s):  
M.A. O’Keefe ◽  
J. Taylor ◽  
D. Owen ◽  
B. Crowley ◽  
K.H. Westmacott ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
User Interface ◽  
Transmission Electron Microscope ◽  
High Voltage ◽  
Materials Science ◽  
Transmission Electron ◽  
On Line ◽  
Electron Microscopes

Remote on-line electron microscopy is rapidly becoming more available as improvements continue to be developed in the software and hardware of interfaces and networks. Scanning electron microscopes have been driven remotely across both wide and local area networks. Initial implementations with transmission electron microscopes have targeted unique facilities like an advanced analytical electron microscope, a biological 3-D IVEM and a HVEM capable of in situ materials science applications. As implementations of on-line transmission electron microscopy become more widespread, it is essential that suitable standards be developed and followed. Two such standards have been proposed for a high-level protocol language for on-line access, and we have proposed a rational graphical user interface. The user interface we present here is based on experience gained with a full-function materials science application providing users of the National Center for Electron Microscopy with remote on-line access to a 1.5MeV Kratos EM-1500 in situ high-voltage transmission electron microscope via existing wide area networks. We have developed and implemented, and are continuing to refine, a set of tools, protocols, and interfaces to run the Kratos EM-1500 on-line for collaborative research. Computer tools for capturing and manipulating real-time video signals are integrated into a standardized user interface that may be used for remote access to any transmission electron microscope equipped with a suitable control computer.

Application of Transmission Electron Microscope and Scanning Electron Microscope in experimental tumor studies

1990 ◽  
Vol 48 (3) ◽  
pp. 306-307
Author(s):  
Gao Fengming
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Malignant Transformation ◽  
Transmission Electron Microscope ◽  
Experimental Tumor ◽  
Transmission Electron ◽  
Embryo Cells ◽  
Tumor Studies ◽  
Scanning Electron

Transmission electron microscope(TEM) and scanning electron microscope(SEM) were widely used in experimental tumor studies. They are useful for evaluation of cellular transformation in vitro, classification of histological types of tumors and treating effect of tumors. We have obtained some results as follows:1. Studies on the malignant transformation of mammalian cells in vitro. Syrian golden hamster embryo cells(SGHEC) were transformed in vitro by ThO2 and/or ore dust. In a few days after dust added into medium, some dust crystals were phagocytized. Two weeks later, malignant transformation took place. These cells were of different size, nuclear pleomorphism, numerous ribosomes, increasing of microvilli on cell surface with various length and thickness, and blebs and ruffles(Figs. 1,2). Myelomonocytic leukemic transformation of mouse embryo cells(MEC) was induced in vitro by 3H-TdR. Transformed cells were become round from fusiform. The number of mitochondria and endoplasmic reticulum was reduced, ribosomes and nucleoli increased, shape of nuclei irregular, microvilli increased, and blebs and ruffles appeared(Fig. 3).

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.

Analysis of Interesting Materials in the Environmental SEM: You Put What in Your Microscope?

2001 ◽  
Vol 7 (S2) ◽  
pp. 776-777
Author(s):  
John F. Mansfield
Keyword(s):  
Electron Microscope ◽  
Chemical Engineering ◽  
Materials Science ◽  
Variable Pressure ◽  
Environmental Scanning ◽  
Specimen Preparation ◽  
Wide Range ◽  
Electron Microscopes ◽  
Scanning Electron Microscopes ◽  
Scanning Electron

The environmental scanning electron microscope (ESEM™) and variable pressure electron microscope (VPSEM) have become accepted tools in the contemporary electron microscopy facility. Their flexibility and their ability to image almost any sample with little, and often no, specimen preparation has proved so attractive that each manufacturer of scanning electron microscopes now markets a low vacuum model.The University of Michigan Electron Microbeam Analysis Laboratory (EMAL) operates two variable pressure instruments, an ElectroScan E3 ESEM and a Hitachi S3200N VPSEM. The E3 ESEM was acquired in the early 1990s with funding from the Amoco Foundation and it has been used to examine an extremely wide variety of different materials. Since EMAL serves the entire university community, and offers support to neighboring institutions and local industry, the types of materials examined span a wide range. There are users from Materials Science & Engineering, Chemical Engineering, Nuclear Engineering, Electrical Engineering, Physics, Chemistry, Geology, Biology, Biophysics, Pharmacy and Pharmacology.

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