Electron beam moiré fringes imaging by image converter tube with a magnetic lens

2016 ◽  
Vol 119 (21) ◽  
pp. 213102
Keyword(s):  
Electron Beam ◽  
Image Converter ◽  
Magnetic Lens ◽  
Moiré Fringes ◽  
Electron Beam Moiré

Measurement of electron beam moire fringes with pulsed-dilation framing camera using different lasers

Optik ◽  
2019 ◽  
Vol 195 ◽  
pp. 163149
Author(s):  
Yanli Bai ◽  
Rongbin Yao ◽  
Haiying Gao ◽  
Xun Wang ◽  
Dajian Liu
Keyword(s):  
Electron Beam ◽  
Moiré Fringes ◽  
Framing Camera ◽  
Electron Beam Moiré

Observation of electron beam moiré fringes in an image conversion tube

2016 ◽  
Vol 170 ◽  
pp. 19-23 ◽  
Author(s):  
Yunfei Lei ◽  
Yubo Liao ◽  
Jing-hua Long ◽  
Houzhi Cai ◽  
Yanli Bai ◽  
...  
Keyword(s):  
Electron Beam ◽  
Image Conversion ◽  
Moiré Fringes ◽  
Electron Beam Moiré

Performance and applications of the holography electron microscope

1993 ◽  
Vol 51 ◽  
pp. 1078-1079
Author(s):  
Akira Tonomura
Keyword(s):  
Electron Beam ◽  
Electron Microscope ◽  
Phase Measurement ◽  
Electron Holography ◽  
Imaging Method ◽  
High Contrast ◽  
Magnetic Lens ◽  
High Brightness ◽  
Holographic Imaging ◽  
Dynamic Observation

Electron holography is a two-step imaging method. However, the ultimate performance of holographic imaging is mainly determined by the brightness of the electron beam used in the hologram-formation process. In our 350kV holography electron microscope (see Fig. 1), the decrease in the inherently high brightness of field-emitted electrons is minimized by superposing a magnetic lens in the gun, for a resulting value of 2 × 109 A/cm2 sr. This high brightness has lead to the following distinguished features. The minimum spacing (d) of carrier fringes is d = 0.09 Å, thus allowing a reconstructed image with a resolution, at least in principle, as high as 3d=0.3 Å. The precision in phase measurement can be as high as 2π/100, since the position of fringes can be known precisely from a high-contrast hologram formed under highly collimated illumination. Dynamic observation becomes possible because the current density is high.

scholarly journals Methods and algorithm for calculating the focal parameters of a hollow conical electron beam in high-voltage glow discharge electron guns with a focusing magnetic lens

2021 ◽  
pp. 17-32
Author(s):  
Igor Melnyk ◽  
Sergey Tugay ◽  
Volodymyr Kyryk ◽  
Iryna Shved
Keyword(s):  
Electron Beam ◽  
Glow Discharge ◽  
High Voltage ◽  
Discrete Mathematics ◽  
Drift Region ◽  
Magnetic Lens ◽  
Focal Distance ◽  
Electron Guns ◽  
Focal Parameters ◽  
Focal Ring

The algorithm is considered for calculating the focal distance of a hollow conical electron beam generated by high-voltage glow discharge electron guns with magnetic focusing of the beam in the drift region, as well as a method for calculating the diameter of the focal ring and its thickness for such a beam. The proposed algorithm is based on the theory of electron drift in the field of a focusing magnetic lens and is designed using the methods of discrete mathematics and the minimax analysis. The obtained simulation results made it possible to establish the influence of the magnetic lens current on the focal diameter of a hollow conical electron beam and on its focal ring thickness. It is shown that the change in the focal parameters of a hollow conical electron beam can be effectively provided through the regulation of the magnetic lens current.

Analysis of an extraordinary electron beam moiré phenomena in a pulse-dilation framing camera

Optik ◽  
2019 ◽  
Vol 199 ◽  
pp. 163516
Author(s):  
Yanli Bai ◽  
Rongbin Yao ◽  
Haiying Gao ◽  
Xun Wang ◽  
Dajian Liu
Keyword(s):  
Electron Beam ◽  
Framing Camera ◽  
Electron Beam Moiré

Electron beam moiré

1993 ◽  
Vol 33 (4) ◽  
pp. 270-277 ◽  
Author(s):  
J. W. Dally ◽  
D. T. Read
Keyword(s):  
Electron Beam ◽  
Electron Beam Moiré

Characteristics of the foil lens for the correction of the spherical aberration and its application to STEM

1978 ◽  
Vol 36 (1) ◽  
pp. 38-39
Author(s):  
M. Hibino ◽  
M. Kuzuya ◽  
T. Hanai ◽  
S. Maruse
Keyword(s):  
Electron Beam ◽  
Potential Distribution ◽  
Spherical Aberration ◽  
Magnetic Lens ◽  
Aperture Diaphragm ◽  
Concave Lens ◽  
Thin Conducting

There have been a number of methods proposed and investigated for the correction of the spherical aberration, since this aberration is one of the most important factors which limit the performance of various kinds of electron beam instruments. A foil lens has been investigated preliminarily and the possibility of correcting the spherical aberration of a conventional magnetic lens with reasonable ease has been shown for the first time.The foil lens studied consists of an aperture diaphragm and a thin conducting foil fundamentally as is shown in Fig. 1, and is simple enough in design and adjustment. When the voltage is applied between the diaphragm and the foil, the curved potential distribution is produced around the aperture and the foil lens acts as a concave or negative lens. This concave lens produces the negative spherical aberration and can be utilized to correct the positive spherical aberration of the conventional magnetic lens.

Development of A 350-KV Holography Electron Microscope and its Applications

1990 ◽  
Vol 48 (1) ◽  
pp. 222-223
Author(s):  
Takeshi Kawasaki ◽  
Junji Endo ◽  
Tsuyoshi Matsuda ◽  
Akira Tonomura
Keyword(s):  
Thin Film ◽  
Electron Beam ◽  
Electron Microscope ◽  
Field Emission ◽  
Source Image ◽  
Electron Holography ◽  
Magnetic Lens ◽  
Lattice Image ◽  
Gold Thin Film ◽  
Spacing Lattice

The 350 kV field-emission electron microscope shown in Fig.1 has been developed to widen the applications of electron holography. A field emission beam is used because it is very bright at first and monochromatic. However, its brightness deteriorates while passing through accelerating electrodes and condenser lenses because of their spherical and chromatic aberrations. A magnetic lens is installed just below a (310)-oriented tungsten tip. A magnetic lens is used so that the electron source image can be located at the most favorable position between the accelerating tube and the first condenser lens to minimize the aberrations and to increase brightness. The measured brightness (probe current) ranges from 1.4x109 A/cm2/sr (0.37 nA) to 6.7x108 A/cm2/sr (2.2 nA) with 10 μA total emission current at 300 kV.These increased brightness and narrow energy spread of the electron beam enable observing fine spacing lattice fringes in a gold thin film. Lattice fringes of 0.065 nm spacing were actually observed in the electron micrograph shown in Fig. 2. The incident electron beam was along the [001] axis, and the (400) and reflected beams were used to form the fringes. A 0.055 nm spacing lattice image is shown in Fig. 3. These fringes resulted from the interference of the electron beam, with an incident axis from the [111] direction into the gold thin film, by the and diffracted beams. This spacing is the shortest observed to date.

Electron Beam Moire´ Study of Fracture of a Glass Fiber Reinforced Plastic Composite

1994 ◽  
Vol 61 (2) ◽  
pp. 402-409 ◽  
Author(s):  
D. T. Read ◽  
J. W. Dally
Keyword(s):  
Electron Beam ◽  
Glass Fiber ◽  
Local Strains ◽  
Glass Fiber Reinforced Plastic ◽  
Fiber Reinforced Plastic ◽  
Plastic Composite ◽  
Glass Fiber Reinforced ◽  
Reinforced Plastic ◽  
Fringe Patterns ◽  
Electron Beam Moiré

Using the method of electron beam moire´, a small region at an interface of a [O2/ 90]s glass fiber reinforced plastic composite has been examined during tensile testing. The tensile test was conducted inside a scanning electron microscope, with a high spatial frequency line grating (10,000 lines/mm) at the interface between a longitudinal ply and a transverse ply. During the test, this region was observed at a magnification of 1900 × . Local strain measurements were made by interpreting the moire´ fringe patterns over gage lengths that varied from 10 to 30 μm. The magnitude and distribution of the local strains depended on the damage that occurred with monotonically increasing load. Load shedding by the transverse ply was evident from the fringe patterns. Extremely high local strains were observed: longitudinal fiber strains up to three percent, normal strains up to three percent, and shear strains up to 40 percent in the epoxy matrix.

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