scholarly journals Transverse structure of the wave function of field emission electron beam determined by intrinsic transverse energy

2018 ◽  
Vol 124 (4) ◽  
pp. 044304 ◽  
Author(s):  
Soichiro Tsujino
Keyword(s):  
Wave Function ◽  
Electron Beam ◽  
Field Emission ◽  
Transverse Energy ◽  
Transverse Structure ◽  
Emission Electron

Development of a 1-MV Field-Emission Electron Microscope III. Electron Optical Design and Development of Field-Emission Electron Gun

2000 ◽  
Vol 6 (S2) ◽  
pp. 1142-1143
Author(s):  
Takaho Yoshida ◽  
Takeshi Kawasaki ◽  
Junji Endo ◽  
Tadao Furutsu ◽  
Isao Matsui ◽  
...  
Keyword(s):  
Electron Beam ◽  
Field Emission ◽  
Optical Design ◽  
Electron Gun ◽  
Electron Holography ◽  
Optimized Design ◽  
Emission Electron ◽  
Transmission Electron ◽  
Electron Microscopes ◽  
Aharonov Bohm

Bright and coherent electron beams have been opening new frontiers in science and technology. So far, we have developed several field-emission transmission electron microscopes (FE-TEM) with increasing accelerating voltages to provide higher beam brightness. By using a 200-kV FE-TEM and electron holography techniques, we directly confirmed the Aharonov-Bohm effect. A 350-kV FE-TEM equipped with a low-temperature specimen stage enabled us to observe moving vortices in superconductors.2 Most Recently, we have developed a new 1-MV FE-TEM with a newly designed FE gun to obtain an even brighter and more coherent electron beam.Electron beam brightness, Br, defined in Figure 1, is suitable for measuring the performance of electron guns, since both lens aberrations and mechanical/electrical vibrations contribute to a decrease in beam brightness, and beam coherency is proportional to (Br)1/2. Therefore, we optimized design of the illuminating system and its operation by maximizing the electron beam brightness.

Evaluation of a 100 kV thermal field emission electron-beam nanolithography system

2000 ◽  
Vol 18 (6) ◽  
pp. 3089 ◽  
Author(s):  
D. M. Tennant ◽  
R. Fullowan ◽  
H. Takemura ◽  
M. Isobe ◽  
Y. Nakagawa
Keyword(s):  
Electron Beam ◽  
Field Emission ◽  
Thermal Field ◽  
Emission Electron

Fabrication and beam characteristics of an ultra-sharp electrode for field emission electron beam

2004 ◽  
Author(s):  
Seong-Soo Kim ◽  
Jong-Hang Lee ◽  
Youn-Chan Yim ◽  
Jung-Woo Hyun ◽  
Cheol-Woo Park ◽  
...  
Keyword(s):  
Electron Beam ◽  
Field Emission ◽  
Emission Electron ◽  
Beam Characteristics

Holographic contrast transfer theory

1992 ◽  
Vol 50 (2) ◽  
pp. 984-985
Author(s):  
R. Plass ◽  
L. D. Marks
Keyword(s):  
Electron Beam ◽  
Transfer Function ◽  
Field Emission ◽  
Electron Holography ◽  
Contrast Transfer Function ◽  
Beam Focusing ◽  
Emission Electron ◽  
Transmission Electron ◽  
Electron Microscopes ◽  
Image Position

With the advent of reliable cold field emission transmission electron microscopes there is substantial interest in using the amplitude and phase information recorded in electron holograms to optically or numerically correct for the coherent aberrations of transmission electron microscopes. However electron holography cannot compensate for incoherent aberrations. The derivation of the contrast transfer function for off axis electron holography in this paper shows there is no fundamental improvement in resolution for electron holography over conventional transmission electron microscopy.Evaluating the contrast transfer function involves mathematically following an electron beam through a field emission electron microscope set up for off axis electron holography. Due to the high coherence of the field emission electron beam coherent aberrations caused by the pre-specimen beam focusing system must be accounted for. Starting with a spacial frequency distribution, C(v), for the electron beam leaving the gun, the electron beam is limited by the condenser aperture and coherently aberrated by the condenser lens and objective pre-field as it passes to the specimen region:

YBCO SQUIDs fabricated by field-emission electron beam source

1999 ◽  
Vol 9 (2) ◽  
pp. 3089-3092
Author(s):  
S.-J. Kim ◽  
J. Chen ◽  
Y. Mizugaki ◽  
K. Nakajima ◽  
T. Yamashita
Keyword(s):  
Electron Beam ◽  
Field Emission ◽  
Beam Source ◽  
Emission Electron

scholarly journals Electron Diagnostics for Extreme High Brightness Nano-Blade Field Emission Cathodes

Instruments ◽  
2019 ◽  
Vol 3 (4) ◽  
pp. 57
Author(s):  
Gerard Lawler ◽  
Kunal Sanwalka ◽  
Yumeng Zhuang ◽  
Victor Yu ◽  
Timo Paschen ◽  
...  
Keyword(s):  
Electron Beam ◽  
Field Emission ◽  
Transverse Energy ◽  
Modern Science ◽  
Damage Threshold ◽  
X Rays ◽  
The Novel ◽  
High Brightness ◽  
Nanoscale Structure ◽  
Field Emission Cathodes

Electron beams are essential tools in modern science. They are ubiquitous in fields ranging from microscopy to the creation of coherent ultra-fast X-rays to lithography. To keep pace with demand, electron beam brightness must be continually increased. One of the main strategic aims of the Center for Bright Beams (CBB), a National Science Foundation Science and Technology Center, is to increase brightness from photocathodes by two orders of magnitude. Improving the state-of-the-art for photoemission-based cathodes is one possibility. Several factors have led to an alternative design becoming an increasing necessity; the nanoscale structure. Field emission sources from nano-tips would be an ideal candidate were it not for their low current and damage threshold. A 1-dimensional extended nano-fabricated blade, i.e., a projected tip, can solve the problems inherent in both designs. The novel geometry has been demonstrated to produce extremely high brightness electron beam bunches and is significantly more robust and easier to manufacture than traditional photocathodes. Theory indicates electron emission up to keV energies. We thus present a system of diagnostics capable of analyzing the cathodes and assessing their viability. The diagnostics are designed to measure the electron spectrum up to keV energies, with sub meV resolution at <100 eV, mean transverse energy (MTE), emission uniformity, and cathode lifetime. We also report preliminary data on total extracted charge and maximum detectable electron energy with a simplified retarding field spectrometer.

Silicon field emission electron beam sources

1995 ◽  
Author(s):  
D. Palmer ◽  
J. Shaw ◽  
H. Gray ◽  
J. Mancusi ◽  
G.E. McGuire ◽  
...  
Keyword(s):  
Electron Beam ◽  
Field Emission ◽  
Emission Electron

Dynamic Observation of Vortices in Superconductors Using Electron Waves

1995 ◽  
Vol 404 ◽  
Author(s):  
A. Tonomura
Keyword(s):  
Electron Beam ◽  
Field Emission ◽  
Direct Observation ◽  
Point Defects ◽  
Lorentz Microscopy ◽  
Dynamic Observation ◽  
Emission Electron ◽  
Coherent Field ◽  
Lines Of Force

AbstractIndividual vortices in superconductors were directly and even dynamically observed by using a “coherent” field emission electron beam. Magnetic lines of force of vortices were quantitatively observed in a holographic interference micrograph and their dynamics were observed by Lorentz microscopy. The interaction of vortices with both line- and point-defects was investigated by direct observation.

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