scholarly journals Прохождение электронов с энергией 10 keV через массив диэлектрических каналов

2021 ◽  
Vol 47 (1) ◽  
pp. 35
Author(s):  
К.А. Вохмянина ◽  
Л.В. Мышеловка ◽  
Д.А. Колесников ◽  
В.С. Сотникова ◽  
А.А. Каплий ◽  
...  
Keyword(s):  
Electron Beam ◽  
Tilt Angle ◽  
Incident Beam ◽  
Beam Axis ◽  
Energy Losses ◽  
Channel Diameter ◽  
Inner Channel

The passage of 10 keV electron beam through a bundle of a hollow polysulfone fiber with an inner channel diameter of 160 ± 60 μm was studied. Dependence of a fraction of the electron beam transmitted through the channels on the tilt angle of the channels relative to the incident beam axis is measured. The fraction of electrons that experienced energy losses of less than 10% after passing through the channels was estimated.

Low Beam Energy X-Ray Micro Analysis: How Useful Is It?

1997 ◽  
Vol 3 (S2) ◽  
pp. 881-882 ◽  
Author(s):  
Dale E. Newbury
Keyword(s):  
Electron Beam ◽  
Beam Energy ◽  
Strong Dependence ◽  
Incident Beam ◽  
X Ray ◽  
Upper Limit ◽  
History Of ◽  
Incident Beam Energy ◽  
Micro Analysis ◽  
Electron Range

Throughout the history of electron-beam X-ray microanalysis, analysts have made good use of the strong dependence of electron range on incident energy (R ≈ E1,7) to optimize the analytical volume when attacking certain types of problems, such as inclusions in a matrix or layered specimens. The “conventional” energy range for quantitative electron beam X-ray microanalysis can be thought of as beginning at 10 keV and extending to the upper limit of the accelerating potential, typically 30 - 50 keV depending on the instrument. The lower limit of 10 keV is selected because this is the lowest incident beam energy for which there is a satisfactory analytical X-ray peak excited from the K-, L-, or M- shells (in a few cases, two shells are simultaneously excited, e.g., Fe-K and Fe-L) for every element in the Periodic Table that is accessible to X-ray spectrometry, beginning with Be (Ek =116 eV) and extending to the transuranic elements. This criterion is based upon establishing a minimum overvoltage U = E0/Ec > 1.25, which is the practical minimum for useful excitation.

scholarly journals The instability of an electron beam with a finite radius in a boundless plasma

1996 ◽  
Vol 14 (4) ◽  
pp. 367-374 ◽  
Author(s):  
G. V. Lizunov ◽  
A. S. Volokitin ◽  
D. B. Skidanov
Keyword(s):  
Growth Rate ◽  
Electron Beam ◽  
Electron Beams ◽  
Wave Number ◽  
Energy Losses ◽  
Finite Radius ◽  
Wave Numbers ◽  
Surrounding Space ◽  
The Waves ◽  
Beam Dimension

Abstract. Within the framework of a linear theory, the instability of an electron beam with a finite radius in a cold magnetised boundless plasma is considered. It is shown that a finite beam dimension influences the generation of quasi-potential waves in two aspects: the perpendicular wave number is quantised so that the frequencies of the waves are subjected to strong selection; a new kind of instability appears due to wave energy losses by emission into surrounding space. Growth rate dependence of wave numbers and frequencies is investigated for typical parameters of experiments with electron beams in space.

Image Degeneration by Charging Effects on Photographic Media

1969 ◽  
Vol 27 ◽  
pp. 132-133
Author(s):  
J. H. Reisner ◽  
J. A. Horner
Keyword(s):  
Electron Beam ◽  
Electrostatic Field ◽  
Effective Charge ◽  
Incident Beam ◽  
High Energy ◽  
Energy Electron ◽  
High Energy Electron ◽  
Conducting Surface ◽  
Charge Center

Insulators irradiated by a high energy electron beam in vacuum become charged positively. The charging produces an electrostatic field which causes the incident beam to be deflected progressively toward the effective charge center. Photographic materials are essentially dielectrics and exhibit charge phenomena which can disturb an image. The charging conditions are aggravated by suspending the photo material remotely from ground, or a conducting surface.

Imaging bulk insulators with secondary electrons in an UHV STEM

1991 ◽  
Vol 49 ◽  
pp. 662-663
Author(s):  
J. Liu ◽  
G. G. Hembree ◽  
J. A. Venable
Keyword(s):  
Electron Beam ◽  
Surface Potential ◽  
Coming Out ◽  
Electron Spectroscopy ◽  
High Spatial Resolution ◽  
Target Material ◽  
Incident Beam ◽  
Secondary Electrons ◽  
Resolution Electron ◽  
Electron Imaging

When an insulator is bombarded by electrons a surface potential will build up if the total number of electrons entering the sample is not equal to that coming out. This potential can be positive or negative depending on the energy of the incident electrons and the target material. The effects of charging will limit, or at least perturb, the use of electron beam techniques for examining the surface properties of insulators. Various methods have been developed to avoid insulator charging. However none of these methods can be applied to high spatial resolution electron beam studies of clean insulator surfaces. At the electron beam energies typically used in STEM instruments the surface of bulk insulators will always acquire a negative potential. Secondary electron imaging (SEI) and Auger electron spectroscopy (AES) would be possible if the surface potential were stable under electron beam illumination and was small compared with the incident beam potential.

The Observation Of Mg)-Al Interface By Hrem and Microdiffraction

1985 ◽  
Vol 43 ◽  
pp. 240-241
Author(s):  
S.Y. Zhang ◽  
J.M. Cowley
Keyword(s):  
Electron Microscopy ◽  
Electron Beam ◽  
High Resolution ◽  
Materials Science ◽  
Incident Beam ◽  
High Resolution Electron Microscopy ◽  
Interface Structure ◽  
Resolution Electron ◽  
Powerful Means ◽  
Interface Structures

The combination of high resolution electron microscopy (HREM) and nanodiffraction techniques provided a powerful means for characterizing many of the interface structures which are of fundamental importance in materials science. In this work the interface structure between magnesium oxide and aluminum has been examined by HREM (with JEM-200CX) and nanodiffraction (with HB-5). The interfaces were formed by evaporating Al on freshly prepared cubic MgO smoke crystals under various vacuum conditions, at 10 -4, 10-5 10-6 and 10-7 torr. The Al layers on the MgO (001) surface are about 100Å thick. TEM observations were performed with the incident beam along the MgO [100] direction so that the interface could be revealed clearly. The nanodiffraction patterns were obtained with the electron beam of 15Å diameter parallel to the interface.

From the Scanning Electron Microscope to the Scanning Electron Macroscope with X-Ray Microanalysis in the ESEM

2000 ◽  
Vol 6 (S2) ◽  
pp. 792-793 ◽  
Author(s):  
Raynald Gauvin
Keyword(s):  
Monte Carlo ◽  
Electron Beam ◽  
Electron Microscope ◽  
Incident Beam ◽  
Correction Procedure ◽  
Measured Intensity ◽  
X Ray ◽  
Image Position ◽  
Corrected Intensity ◽  
Scanning Electron

Recently, a new correction procedure has been proposed in order to perform X-Ray microanalysis in the ESEM or in the VP-SEM1. This new correction procedure is based on this equation:where I is the measured intensity at a given pressure P, Ip is the intensity that would be generated without any gas in the microscope (the corrected intensity) and Im is the intensity with complete scattering of the electron beam. Im is therefore the contribution of the skirt on I. In equation (1), fp is the fraction of the incident beam, which is not scattered by the gas above the specimen, and it can be obtained from Monte Carlo simulations or from an analytical equation.

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