Computer simulation of a 360° field‐of‐view ‘‘top‐hat’’ electrostatic analyzer

1988 ◽  
Vol 59 (1) ◽  
pp. 146-155 ◽  
Author(s):  
M. J. Sablik ◽  
D. Golimowski ◽  
J. R. Sharber ◽  
J. D. Winningham
Keyword(s):  
Computer Simulation ◽  
Field Of View ◽  
Electrostatic Analyzer

2π‐radian field‐of‐view toroidal electrostatic analyzer

1988 ◽  
Vol 59 (5) ◽  
pp. 743-751 ◽  
Author(s):  
D. T. Young ◽  
S. J. Bame ◽  
M. F. Thomsen ◽  
R. H. Martin ◽  
J. L. Burch ◽  
...  
Keyword(s):  
Field Of View ◽  
Electrostatic Analyzer

scholarly journals TELESCOPS WITH DIFFERENT MAGNIFICATION

2021 ◽  
Vol 6 ◽  
pp. 155-161
Author(s):  
Nikolay I. Kolmogorcev ◽  
Tatiana N. Khatsevich
Keyword(s):  
Computer Simulation ◽  
Optical System ◽  
Field Of View ◽  
Paraxial Approximation

The characteristics of pankratic telescopes are considered. It was found that in most modern models of pancratic telescopes, the ratio of the change in magnification and the ratio of the change in the angle of the field of view are not equal to each other. The synthesis of an optical system with a pacratic change of characteristics in the ocular part in the paraxial approximation was carried out using the methods of computer simulation. The analysis of a particular simulation result made it possible to identify the cause of the revealed inequality.

scholarly journals Angular Dependence of Atmospheric Turbulence Effect in Speckle Interferometry

1979 ◽  
Vol 50 ◽  
pp. 26-1-26-25
Author(s):  
David L. Fried
Keyword(s):  
Computer Simulation ◽  
Phase Shift ◽  
Preliminary Analysis ◽  
Speckle Interferometry ◽  
Point Sources ◽  
Field Of View ◽  
Frequency Separation ◽  
Propagation Path ◽  
Turbulence Effect ◽  
Incorrect Information

AbstractThe concepts of speckle interferometry as developed by Labeyrie, and of speckle imagery as formulated by Knox and Thompson are analyzed for dependence on field-of-view size. The preliminary analysis, assuming isoplanatism rederives the results of Korff, and derives the result previously inferred by Knox and Thompson from computer simulation, that allowable spatial frequency separation for difference of phase shift determination must be less than r0/λ When the assumption of isoplanatism is dropped, results are obtained for the expected object power spectrum in speckle interferometry and for the expected bispectrum in speckle imagery, showing the dependence on angular spread for an object consisting of a pair of point sources. An angle, ϑ, is defined (in terms of an integral over the strength of turbulence distribution along the propagation path), which bounds the range within which there are no significant anisoplanatism effects. It is noted that the effect of anisoplanatism is not to attenuate the information bearing signal but rather to impose incorrect information on the signal. Thus anisoplanatism can result in incorrect conclusions with no indication that there is a problem.

scholarly journals Research on Instrument Visibility of Ozone Wind Imaging Interferometer

2021 ◽  
Vol 13 (6) ◽  
pp. 1062
Author(s):  
Chunmin Zhang ◽  
Xiao Du ◽  
Tingyu Yan ◽  
Guixiu Li
Keyword(s):  
Remote Sensing ◽  
Computer Simulation ◽  
Glass Surface ◽  
Wind Field ◽  
Theoretical Basis ◽  
Beam Splitter ◽  
Field Of View ◽  
Mirror Surface ◽  
Imaging Interferometer ◽  
Practical Guidance

This paper discussed the principle of the ozone wind imaging interferometer developed by our group, which used remote sensing method to detect wind field and ozone concentration simultaneously, focused on the analysis and calculation of the instrument visibility and gave the theoretical representation of the instrument visibility. Computer simulation was used to analyze the influence of the system transmittance, compensation glass surface tilt and mirror surface accuracy on the instrument visibility. The results showed that the splitting ratio of the beam splitter and the field of view would affect the distribution of the instrument visibility; the tilt angle of the compensation glass surface can greatly affect the instrument visibility. We also gave the random error range of wind field speed and temperature at the instrument visibility U > 0.9. This research provides an important theoretical basis and practical guidance for the development and engineering of ozone wind imaging interferometers.

Very High Resolution Analysis of the Dynamics of a Coronal Plasmoid

1994 ◽  
Vol 144 ◽  
pp. 593-596
Author(s):  
O. Bouchard ◽  
S. Koutchmy ◽  
L. November ◽  
J.-C. Vial ◽  
J. B. Zirker
Keyword(s):  
High Resolution ◽  
Solar Eclipse ◽  
Total Solar Eclipse ◽  
Field Of View ◽  
Small Field ◽  
High Resolution Analysis ◽  
Ccd Observations ◽  
Resolution Analysis ◽  
Very High ◽  
Small Field Of View

AbstractWe present the results of the analysis of a movie taken over a small field of view in the intermediate corona at a spatial resolution of 0.5“, a temporal resolution of 1 s and a spectral passband of 7 nm. These CCD observations were made at the prime focus of the 3.6 m aperture CFHT telescope during the 1991 total solar eclipse.

Dynamic Scanning Electron Microscopy of Small Particles

1975 ◽  
Vol 33 ◽  
pp. 280-281
Author(s):  
W. Krakow ◽  
W. C. Nixon
Keyword(s):  
Electron Microscopy ◽  
Low Noise ◽  
Time Sequence ◽  
Field Of View ◽  
Video Tape ◽  
Small Particles ◽  
Polystyrene Spheres ◽  
Field Distributions ◽  
Dynamic Scanning ◽  
Scanning Electron

The scanning electron microscope (SEM) can be run at television scanning rates and used with a video tape recorder to observe dynamic specimen changes. With a conventional tungsten source, a low noise TV image is obtained with a field of view sufficient to cover the area of the specimen to be recorded. Contrast and resolution considerations have been elucidated and many changing specimens have been studied at TV rates.To extend the work on measuring the magnitude of charge and field distributions of small particles in the SEM, we have investigated their motion and electrostatic interaction at TV rates. Fig. 1 shows a time sequence of polystyrene spheres on a conducting grating surface inclined to the microscope axis. In (la) there are four particles present in the field of view, while in (lb) a fifth particle has moved into view.

STM studies of crystal growth

1991 ◽  
Vol 49 ◽  
pp. 374-375
Author(s):  
M. G. Lagally
Keyword(s):  
Crystal Growth ◽  
Molecular Beam ◽  
Chemical Vapor ◽  
Sputter Deposition ◽  
Field Of View ◽  
Scanning Tunneling ◽  
Wide Field ◽  
Tunneling Microscopy ◽  
Wide Field Of View ◽  
The One

It has been recognized since the earliest days of crystal growth that kinetic processes of all Kinds control the nature of the growth. As the technology of crystal growth has become ever more refined, with the advent of such atomistic processes as molecular beam epitaxy, chemical vapor deposition, sputter deposition, and plasma enhanced techniques for the creation of “crystals” as little as one or a few atomic layers thick, multilayer structures, and novel materials combinations, the need to understand the mechanisms controlling the growth process is becoming more critical. Unfortunately, available techniques have not lent themselves well to obtaining a truly microscopic picture of such processes. Because of its atomic resolution on the one hand, and the achievable wide field of view on the other (of the order of micrometers) scanning tunneling microscopy (STM) gives us this opportunity. In this talk, we briefly review the types of growth kinetics measurements that can be made using STM. The use of STM for studies of kinetics is one of the more recent applications of what is itself still a very young field.

A High Resolution Scanning Microscope

1968 ◽  
Vol 26 ◽  
pp. 356-357
Author(s):  
A. V. Crewe ◽  
J. Wall ◽  
L. M. Welter
Keyword(s):  
High Resolution ◽  
Field Emission ◽  
Spherical Aberration ◽  
Focal Length ◽  
Spot Size ◽  
Emission Source ◽  
Field Of View ◽  
Scanning Microscope ◽  
Magnetic Lens ◽  
High Quality

A scanning microscope using a field emission source has been described elsewhere. This microscope has now been improved by replacing the single magnetic lens with a high quality lens of the type described by Ruska. This lens has a focal length of 1 mm and a spherical aberration coefficient of 0.5 mm. The final spot size, and therefore the microscope resolution, is limited by the aberration of this lens to about 6 Å.The lens has been constructed very carefully, maintaining a tolerance of + 1 μ on all critical surfaces. The gun is prealigned on the lens to form a compact unit. The only mechanical adjustments are those which control the specimen and the tip positions. The microscope can be used in two modes. With the lens off and the gun focused on the specimen, the resolution is 250 Å over an undistorted field of view of 2 mm. With the lens on,the resolution is 20 Å or better over a field of view of 40 microns. The magnification can be accurately varied by attenuating the raster current.

Ratio imaging of intracellular ion concentration

1992 ◽  
Vol 50 (2) ◽  
pp. 1160-1161
Author(s):  
Stephen R. Bolsover
Keyword(s):  
Individual Cell ◽  
Video Camera ◽  
Field Of View ◽  
Ion Concentration ◽  
Fluorescence Signal ◽  
Ion Imaging ◽  
Ratiometric Fluorescence ◽  
Ratio Imaging ◽  
The Mean ◽  
The Many

The field of intracellular ion concentration measurement expanded greatly in the 1980's due primarily to the development by Roger Tsien of ratiometric fluorescence dyes. These dyes have many applications, and in particular they make possible to image ion concentrations: to produce maps of the ion concentration within living cells. Ion imagers comprise a fluorescence microscope, an imaging light detector such as a video camera, and a computer system to process the fluorescence signal and display the map of ion concentration.Ion imaging can be used for two distinct purposes. In the first, the imager looks at a field of cells, measuring the mean ion concentration in each cell of the many in the field of view. One can then, for instance, challenge the cells with an agonist and examine the response of each individual cell. Ion imagers are not necessary for this sort of experiment: one can instead use a system that measures the mean ion concentration in a just one cell at any one time. However, they are very much more convenient.

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