Solution of electron optics problems with space charge in 2D and 3D

1995 ◽  
Author(s):  
John A. Rouse ◽  
Xieqing Zhu ◽  
Eric Munro
Keyword(s):  
Space Charge ◽  
Electron Optics ◽  
2D And 3D

Investigation of an NEA Diamond Vacuum Microtriode Array

1996 ◽  
Vol 423 ◽  
Author(s):  
C. W. Hatfield ◽  
G. L. Bilbro ◽  
A. S. Morris ◽  
P. K. Baumann ◽  
B. L. Ward ◽  
...  
Keyword(s):  
Space Charge ◽  
Applied Voltage ◽  
Circuit Simulation ◽  
Emission Current ◽  
Microwave Circuit ◽  
Electron Optics ◽  
Electrical Measurements ◽  
Simulation Data ◽  
Diamond Surfaces ◽  
Rf Amplifier

AbstractThe properties and characteristics of vacuum microtriodes based on NEA diamond surfaces were modelled. Specifically, an NEA diamond vacuum microtriode array was investigated using electrical measurements, electron optics software, and microwave circuit simulation. Data for emission current versus applied voltage for various anode-to-cathode distances for diamond NEA surfaces was analyzed and various parameters were extracted. Electron optics software was used to determine Fowler-Nordheim and space-charge-limited DC I-V characteristics for each microtriode. Microwave circuit simulation was done to determine the behavior of arrays of these vacuum microtriodes in an RF amplifier circuit.

Use of Space Charge in Electron Optics

1955 ◽  
Vol 26 (3) ◽  
pp. 327-330 ◽  
Author(s):  
E. A. Ash
Keyword(s):  
Space Charge ◽  
Electron Optics ◽  
Use Of Space

scholarly journals Self-consistent long-term dynamics of space charge driven resonances in 2D and 3D

2021 ◽  
Vol 24 (2) ◽  
Author(s):  
Ingo Hofmann ◽  
Adrian Oeftiger ◽  
Oliver Boine-Frankenheim
Keyword(s):  
Space Charge ◽  
Self Consistent ◽  
2D And 3D

On an Application of the Metallurgical Stage to Chromosome Morphology

1967 ◽  
Vol 25 ◽  
pp. 28-29
Author(s):  
Godfrey C. Hoskins
Keyword(s):  
Human Chromosome ◽  
Electron Micrographs ◽  
Chromosome Morphology ◽  
Electron Optics ◽  
Electron Micrograph ◽  
Photographic Evidence ◽  
Sophisticated Equipment ◽  
Periodic Arrangement

The first serious electron microscooic studies of chromosomes accompanied by pictures were by I. Elvers in 1941 and 1943. His prodigious study, from the manufacture of micronets to the development of procedures for interpreting electron micrographs has gone all but unnoticed. The application of todays sophisticated equipment confirms many of the findings he gleaned from interpretation of images distorted by the electron optics of that time. In his figure 18 he notes periodic arrangement of pepsin sensitive “prickles” now called secondary fibers. In his figure 66 precise regularity of arrangement of these fibers can be seen. In his figure 22 he reproduces Siegbahn's first stereoscopic electron micrograph of chromosomes.The two stereoscopic pairs of electron micrographs of a human chromosome presented here were taken with a metallurgical stage on a Phillips EM200. These views are interpreted as providing photographic evidence that primary fibers (1°F) about 1,200Å thick are surrounded by secondary fibers (2°F) arranged in regular intervals of about 2,800Å in this metanhase human chromosome. At the telomere the primary fibers bend back on themselves and entwine through the center of each of each chromatid. The secondary fibers are seen to continue to surround primary fibers at telomeres. Thus at telomeres, secondary fibers present a surface not unlike that of the side of the chromosome, and no more susceptible to the addition of broken elements from other chromosomes.

Applications of Photoelectron Microscopy

1976 ◽  
Vol 34 ◽  
pp. 506-507
Author(s):  
William J. Baxter
Keyword(s):  
Electron Microscopy ◽  
Thermal Decomposition ◽  
Chemical Composition ◽  
Ultraviolet Radiation ◽  
Thin Layer ◽  
Edge Effects ◽  
Electron Optics ◽  
Surface Layers ◽  
Crystalline Orientation ◽  
Fluorescent Screen

In this form of electron microscopy, photoelectrons emitted from a metal by ultraviolet radiation are accelerated and imaged onto a fluorescent screen by conventional electron optics. image contrast is determined by spatial variations in the intensity of the photoemission. The dominant source of contrast is due to changes in the photoelectric work function, between surfaces of different crystalline orientation, or different chemical composition. Topographical variations produce a relatively weak contrast due to shadowing and edge effects.Since the photoelectrons originate from the surface layers (e.g. ∼5-10 nm for metals), photoelectron microscopy is surface sensitive. Thus to see the microstructure of a metal the thin layer (∼3 nm) of surface oxide must be removed, either by ion bombardment or by thermal decomposition in the vacuum of the microscope.

Analysis of 2D and 3D defects associated with precipitation of Cu in silicon

1991 ◽  
Vol 49 ◽  
pp. 870-871
Author(s):  
P.M. Rice ◽  
MJ. Kim ◽  
R.W. Carpenter
Keyword(s):  
Colony Growth ◽  
Dark Field ◽  
Dark Side ◽  
Silicide Phase ◽  
Strain Fields ◽  
Near Surface ◽  
Unknown Composition ◽  
Secondary Precipitates ◽  
20 Nm ◽  
2D And 3D

Extrinsic gettering of Cu on near-surface dislocations in Si has been the topic of recent investigation. It was shown that the Cu precipitated hetergeneously on dislocations as Cu silicide along with voids, and also with a secondary planar precipitate of unknown composition. Here we report the results of investigations of the sense of the strain fields about the large (~100 nm) silicide precipitates, and further analysis of the small (~10-20 nm) planar precipitates.Numerous dark field images were analyzed in accordance with Ashby and Brown's criteria for determining the sense of the strain fields about precipitates. While the situation is complicated by the presence of dislocations and secondary precipitates, micrographs like those shown in Fig. 1(a) and 1(b) tend to show anomalously wide strain fields with the dark side on the side of negative g, indicating the strain fields about the silicide precipitates are vacancy in nature. This is in conflict with information reported on the η'' phase (the Cu silicide phase presumed to precipitate within the bulk) whose interstitial strain field is considered responsible for the interstitial Si atoms which cause the bounding dislocation to expand during star colony growth.

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