Notice of Removal: Electron-optical system with Field Emitter For Spectroscopic Gyrotrons

2019 ◽  
Author(s):  
G.G. Sominskii ◽  
E.P. Taradaev ◽  
T.A. Tumareva ◽  
A.A. Rukavitsina ◽  
M.E. Givargizov ◽  
...  
Keyword(s):  
Optical System ◽  
Electron Optical System ◽  
Field Emitter

The concept of an electron-optical system with field emitter for a spectroscopic gyrotron

2016 ◽  
Vol 78 ◽  
pp. 185-189 ◽  
Author(s):  
M.Yu. Glyavin ◽  
V.N. Manuilov ◽  
G.G. Sominskii ◽  
E.P. Taradaev ◽  
T.A. Tumareva
Keyword(s):  
Optical System ◽  
Electron Optical System ◽  
Field Emitter

A Field Emission System For Transmission Electron Microscopy

1973 ◽  
Vol 31 ◽  
pp. 298-299
Author(s):  
Michel Troyonal ◽  
Huei Pei Kuoal ◽  
Benjamin M. Siegelal
Keyword(s):  
Electron Microscope ◽  
Field Emission ◽  
Optical System ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Objective Lens ◽  
Electron Optical System ◽  
Cross Sectional ◽  
Transmission Electron ◽  
Emission System

A field emission system for our experimental ultra high vacuum electron microscope has been designed, constructed and tested. The electron optical system is based on the prototype whose performance has already been reported. A cross-sectional schematic illustrating the field emission source, preaccelerator lens and accelerator is given in Fig. 1. This field emission system is designed to be used with an electron microscope operated at 100-150kV in the conventional transmission mode. The electron optical system used to control the imaging of the field emission beam on the specimen consists of a weak condenser lens and the pre-field of a strong objective lens. The pre-accelerator lens is an einzel lens and is operated together with the accelerator in the constant angular magnification mode (CAM).

Atomic Resolution in Crystal Aperture Stem

1990 ◽  
Vol 48 (1) ◽  
pp. 236-237
Author(s):  
J T Fourie
Keyword(s):  
Optical System ◽  
Spherical Aberration ◽  
Three Dimensional ◽  
Transmission Function ◽  
Optical Systems ◽  
Bragg Angle ◽  
Electron Optical System ◽  
Intimate Contact ◽  
Diffraction Effects ◽  
Design Aspect

The attempts at improvement of electron optical systems to date, have largely been directed towards the design aspect of magnetic lenses and towards the establishment of ideal lens combinations. In the present work the emphasis has been placed on the utilization of a unique three-dimensional crystal objective aperture within a standard electron optical system with the aim to reduce the spherical aberration without introducing diffraction effects. A brief summary of this work together with a description of results obtained recently, will be given.The concept of utilizing a crystal as aperture in an electron optical system was introduced by Fourie who employed a {111} crystal foil as a collector aperture, by mounting the sample directly on top of the foil and in intimate contact with the foil. In the present work the sample was mounted on the bottom of the foil so that the crystal would function as an objective or probe forming aperture. The transmission function of such a crystal aperture depends on the thickness, t, and the orientation of the foil. The expression for calculating the transmission function was derived by Hashimoto, Howie and Whelan on the basis of the electron equivalent of the Borrmann anomalous absorption effect in crystals. In Fig. 1 the functions for a g220 diffraction vector and t = 0.53 and 1.0 μm are shown. Here n= Θ‒ΘB, where Θ is the angle between the incident ray and the (hkl) planes, and ΘB is the Bragg angle.

On Designing the Electron-Optical System of a Multibarrel Gyrotron

2021 ◽  
Author(s):  
V. E. Zapevalov ◽  
A. S. Zuev ◽  
A. N. Kuftin ◽  
O. P. Plankin ◽  
E. S. Semenov
Keyword(s):  
Optical System ◽  
Electron Optical System
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