scholarly journals Development of an Electron-Atom Compton Scattering Apparatus Using a Picosecond Pulsed Electron Gun

Atoms ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 19
Author(s):  
Yuichi Tachibana ◽  
Yuuki Onitsuka ◽  
Masakazu Yamazaki ◽  
Masahiko Takahashi
Keyword(s):  
Compton Scattering ◽  
Electron Gun ◽  
Future Application ◽  
Pulsed Electron Beam ◽  
Electron Atom ◽  
Real Time Measurement ◽  
Pump And Probe ◽  
Molecular Reaction ◽  
Evolving System ◽  
Technical Details

An apparatus has been developed for electron-atom Compton scattering experiments that can employ a pulsed laser and a picosecond pulsed electron beam in a pump-and-probe scheme. The design and technical details of the apparatus are described. Furthermore, experimental results on the Xe atom in its ground state are presented to illustrate the performance of the pulsed electron gun and the detection and spectrometric capabilities for scattered electrons. The scope of future application is also discussed, involving real-time measurement of intramolecular force acting on each constituent atom with different mass numbers, in a transient, evolving system during a molecular reaction.

scholarly journals Production of Nanopowders of Metal Oxides Using Pulsed Electron Beam in Low Pressure Gas

2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
S. Yu. Sokovnin ◽  
V. G. Il'ves
Keyword(s):  
Electron Beam ◽  
Room Temperature ◽  
Room Temperature Ferromagnetism ◽  
Low Pressure ◽  
Electron Gun ◽  
Specific Power ◽  
Large Area ◽  
Pulsed Electron Beam ◽  
Higher Power ◽  
Characteristic Particle

The installation for production of metal oxide nanopowders was created. The method involves evaporation of the target by a pulsed-electron beam, condensation of the vapors of the material in a low-pressure gas, and deposition of nanopowders on a cold large-area crystallizer. In a new installation, a higher-power electron gun with a hollow cathode, which ensures the formation of the current pulse of the electron beam with amplitude up to 1 A and a duration of 100 μs, and a crystallizer of a larger diameter (0.3 m) and length (0.5 m), which makes it possible to decrease the agglomeration, were used. The results of the evaporation of targets made of YSZ, CeGdOx, Zn-ZnO, Al2O3, and ZnO were presented. Room-temperature ferromagnetism has been observed in YSZ, Zn-ZnO, and Cu(Al)-doped Al2O3. The proposed method makes it possible to obtain nanopowders of oxides with a characteristic particle size of 3–5 nm and agglomerates consisting of them 20–600 nm in size, specific surfaces of up 338 m2/g, productivity of up to 12 g/h, and a specific power consumption ≥112 (W h)/g.

Development of multi-channel apparatus for electron-atom Compton scattering to study the momentum distribution of atoms in a molecule

2017 ◽  
Vol 88 (6) ◽  
pp. 063103 ◽  
Author(s):  
Masakazu Yamazaki ◽  
Masaki Hosono ◽  
Yaguo Tang ◽  
Masahiko Takahashi
Keyword(s):  
Compton Scattering ◽  
Momentum Distribution ◽  
Electron Atom

Transient self-dewetting of steels after pulsed electron beam melting

2001 ◽  
Vol 16 (8) ◽  
pp. 2343-2349 ◽  
Author(s):  
N. Mingolo ◽  
A. N. Roviglione ◽  
O. E. Marti´nez
Keyword(s):  
Electron Beam Melting ◽  
Liquid Surface ◽  
Electron Gun ◽  
Nonlinear Instability ◽  
Metallic Surfaces ◽  
Pulsed Electron Beam ◽  
Purity Iron ◽  
High Purity Iron ◽  
Fast Cooling ◽  
Steel Surfaces

Experimental evidence of transient self-dewetting of metallic surfaces is presented. Steel surfaces are melted by a pulsed electron gun, and the subsequent fast cooling against its substrate gives rise to the formation of characteristic patterns that we attribute to the dewetting of the liquid film. The patterns formed are similar to those obtained by spinodal dewetting, that is, when the dewetting action develops from a nonlinear instability on the liquid surface, and not from holes nucleation. High-purity iron does not show a similar behavior, indicating that the origin of the instability is due to the influence of the sulfur in the temperature dependence of the surface tension of the melt, which gives rise to a Be’nard-Marangoni instability.

A High Performance Energy Analyzer for Use in Electron Scanning Microscopy

1969 ◽  
Vol 27 ◽  
pp. 14-15
Author(s):  
A. V. Crewe ◽  
M. Isaacson ◽  
D. Johnson
Keyword(s):  
High Performance ◽  
Vertical Plane ◽  
Median Plane ◽  
Electron Gun ◽  
Uniform Field ◽  
Loss Mechanism ◽  
Electron Scanning Microscopy ◽  
Sector Type ◽  
Double Focusing ◽  
Electron Energy Loss

A double focusing magnetic spectrometer has been constructed for use with a field emission electron gun scanning microscope in order to study the electron energy loss mechanism in thin specimens. It is of the uniform field sector type with curved pole pieces. The shape of the pole pieces is determined by requiring that all particles be focused to a point at the image slit (point 1). The resultant shape gives perfect focusing in the median plane (Fig. 1) and first order focusing in the vertical plane (Fig. 2).

Observation of Phase Contrast Images in STEM and CTEM Modes by Using 100 kV Field Emission Electron Gun

1974 ◽  
Vol 32 ◽  
pp. 390-391
Author(s):  
Y. Harada ◽  
T. Goto ◽  
H. Koike ◽  
T. Someya
Keyword(s):  
Field Emission ◽  
Phase Contrast ◽  
Image Formation ◽  
Fresnel Diffraction ◽  
Experimental Results ◽  
Electron Gun ◽  
Scanning Microscopy ◽  
Emission Electron ◽  
Lattice Images

Since phase contrasts of STEM images, that is, Fresnel diffraction fringes or lattice images, manifest themselves in field emission scanning microscopy, the mechanism for image formation in the STEM mode has been investigated and compared with that in CTEM mode, resulting in the theory of reciprocity. It reveals that contrast in STEM images exhibits the same properties as contrast in CTEM images. However, it appears that the validity of the reciprocity theory, especially on the details of phase contrast, has not yet been fully proven by the experiments. In this work, we shall investigate the phase contrast images obtained in both the STEM and CTEM modes of a field emission microscope (100kV), and evaluate the validity of the reciprocity theory by comparing the experimental results.

Structure and migration of planar defects in crystals observed in atomic scale

1978 ◽  
Vol 36 (1) ◽  
pp. 284-285 ◽  
Author(s):  
H. Hashimoto ◽  
Y. Sugimoto ◽  
Y. Takai ◽  
H. Endoh
Keyword(s):  
Electron Microscope ◽  
Rotation Angle ◽  
Crystal Surface ◽  
Electron Gun ◽  
Atomic Scale ◽  
Present Observation ◽  
Twist Boundary ◽  
Optical Magnification ◽  
Zinc Crystal ◽  
And Migration

As was demonstrated by the present authors that atomic structure of simple crystal can be photographed by the conventional 100 kV electron microscope adjusted at “aberration free focus (AFF)” condition. In order to operate the microscope at AFF condition effectively, highly stabilized electron beams with small energy spread and small beam divergence are necessary. In the present observation, a 120 kV electron microscope with LaB6 electron gun was used. The most of the images were taken with the direct electron optical magnification of 1.3 million times and then magnified photographically.1. Twist boundary of ZnSFig. 1 is the image of wurtzite single crystal with twist boundary grown on the surface of zinc crystal by the reaction of sulphur vapour of 1540 Torr at 500°C. Crystal surface is parallel to (00.1) plane and electron beam is incident along the axis normal to the crystal surface. In the twist boundary there is a dislocation net work between two perfect crystals with a certain rotation angle.

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