Three-dimensional continuous modeling of beam-electron cloud interaction: Comparison with analytic models and predictions for the present and future circular machines

2006 ◽  
Vol 13 (5) ◽  
pp. 056710 ◽  
Author(s):  
A. Z. Ghalam ◽  
T. Katsouleas ◽  
V. K. Decyk ◽  
C. K. Huang ◽  
W. B. Mori ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Electron Cloud ◽  
Beam Electron ◽  
Continuous Modeling ◽  
Analytic Models

scholarly journals Three-Dimensional Spatial Distribution of Synapses in the Neocortex: A Dual-Beam Electron Microscopy Study

2013 ◽  
Vol 24 (6) ◽  
pp. 1579-1588 ◽  
Author(s):  
Angel Merchán-Pérez ◽  
José-Rodrigo Rodríguez ◽  
Santiago González ◽  
Víctor Robles ◽  
Javier DeFelipe ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Spatial Distribution ◽  
Three Dimensional ◽  
Microscopy Study ◽  
Electron Microscopy Study ◽  
Beam Electron ◽  
Dual Beam

Geometries, stabilities and electronic properties of bimetallic AlnPdm (n = 1–10, m = 1,2) clusters

2018 ◽  
Vol 32 (07) ◽  
pp. 1850073
Author(s):  
Ya-Fen Li ◽  
Fu-Qiang Zhang ◽  
Fang-Qin Ren ◽  
Wen-Jin Ma
Keyword(s):  
Electronic Properties ◽  
Three Dimensional ◽  
Dft Method ◽  
Electron Cloud ◽  
Nonlinear Optical Effect ◽  
Aluminum Clusters ◽  
Surface Sites ◽  
Orbital Hybridization ◽  
Peripheral Position ◽  
Pd Clusters

The geometries, stabilities and electronic properties of Al[Formula: see text]Pd[Formula: see text] (n = 1–10, m = 1, 2) have been systematically investigated by using the DFT method at B3PW91/GENECP level. The optimized results indicate that the lowest-energy structures of Al[Formula: see text]Pd clusters prefer to form three-dimensional (3D) structures and the Pd atom occupies a peripheral position of Al[Formula: see text]Pd clusters. The most stable Al[Formula: see text]Pd2 clusters can be obtained by adding one Al atom to the most stable structure of Al[Formula: see text]Pd2 clusters except for n = 7 and 10. The two Pd atoms are found to occupy the exclusive surface sites. The analysis of stabilities reveals that Al3Pd[Formula: see text] and Al7Pd[Formula: see text] clusters are more stable than their neighbors. The doping of Pd atoms enhances the stabilities of aluminum clusters. The charges always transfer from Al atoms to Pd atoms in Al[Formula: see text]Pd[Formula: see text] clusters. There exists strong spd orbital hybridization between Pd and Al. The results of polarizability imply that the nucleus and electron cloud of these clusters are easily affected by the external field and the nonlinear optical effect of Al[Formula: see text]Pd and Al[Formula: see text]Pd2 clusters is enhanced with the increase of cluster size.

scholarly journals Новые типы фотонно-кристаллических двухзазорных резонаторов для миниатюрных многолучевых клистронов коротковолновой части СВЧ-диапазона

2020 ◽  
Vol 46 (3) ◽  
pp. 35
Author(s):  
А.В. Ливчина ◽  
В.А. Царев
Keyword(s):  
Photonic Crystal ◽  
Electron Flow ◽  
Three Dimensional ◽  
Solid Metal ◽  
Beam Electron ◽  
Oscillatory Systems ◽  
Highly Efficient ◽  
Dimensional Parameters ◽  
Metal Body ◽  
Electrodynamic Modeling

The results of three-dimensional electrodynamic modeling of photonic-crystal double-gaps resonators designed for use in miniature multi-beams klystrons. In the new resonators, the solid metal body is replaced by a similarly shaped lattice of metal rods, allowing to suppress parasitic types of vibrations. It is shown that such oscillatory systems have an improved complex of electrodynamic and mass-dimensional parameters. The conditions of tuning these systems to a highly efficient two-mode of interaction are investigated with multi-beam electron flow simultaneously at two frequencies corresponding to the main (antiphase) and the first higher (in-phase) types of oscillations.

scholarly journals Effects of Strain Rates on Kinetics of Elements of Repeated Pattern Structures: A Continuous Modeling Approach

2012 ◽  
Vol 19 (4) ◽  
pp. 545-554 ◽  
Author(s):  
A. Salehian
Keyword(s):  
Three Dimensional ◽  
Dimensional Structure ◽  
Strain Rates ◽  
Pattern Structures ◽  
Strain Components ◽  
Equivalent Continuum Model ◽  
Promising Solution ◽  
Frequency Changes ◽  
Continuous Modeling ◽  
Kinetics Of

Space inflatable technology is a promising solution to placing large metrology systems in space. Lighter weight, higher packaging efficiency, and easier maintenance are among a few of their advantages over mechanically deployed structures. On the other hand, their large volume after deployment makes them susceptible to disturbances in space. Therefore, vibration control is one major issue for this technology. The present work is an extension of the previous work of the author on continuum modeling of these structures for their vibrations analysis. Kinetic and strain energy expressions of the fundamental lattice elements of a structure are expanded in terms of the nodal displacement components. Certain assumptions are made to reduce the order of strain components in a three-dimensional structure in order to find the equivalent continuum model. Additionally, this work includes the effects of strain rates on the kinetics of these structures. The frequency results for various structures are compared to those of a previous model which neglects such effects. It is shown that the frequency changes are noticeable when the strain rate components are included in the kinetic energy derivations.

Burgers Vector Analysis of Vertical Dislocations in Ge Crystals by Large-Angle Convergent Beam Electron Diffraction

2015 ◽  
Vol 21 (3) ◽  
pp. 637-645 ◽  
Author(s):  
Heiko Groiss ◽  
Martin Glaser ◽  
Anna Marzegalli ◽  
Fabio Isa ◽  
Giovanni Isella ◽  
...  
Keyword(s):  
Electron Diffraction ◽  
Large Angle ◽  
Three Dimensional ◽  
Chemical Vapor ◽  
Dark Field ◽  
Convergent Beam Electron Diffraction ◽  
Vector Analysis ◽  
Burgers Vector ◽  
Beam Electron ◽  
Convergent Beam

AbstractBy transmission electron microscopy with extended Burgers vector analyses, we demonstrate the edge and screw character of vertical dislocations (VDs) in novel SiGe heterostructures. The investigated pillar-shaped Ge epilayers on prepatterned Si(001) substrates are an attempt to avoid the high defect densities of lattice mismatched heteroepitaxy. The Ge pillars are almost completely strain-relaxed and essentially defect-free, except for the rather unexpected VDs. We investigated both pillar-shaped and unstructured Ge epilayers grown either by molecular beam epitaxy or by chemical vapor deposition to derive a general picture of the underlying dislocation mechanisms. For the Burgers vector analysis we used a combination of dark field imaging and large-angle convergent beam electron diffraction (LACBED). With LACBED simulations we identify ideally suited zeroth and second order Laue zone Bragg lines for an unambiguous determination of the three-dimensional Burgers vectors. By analyzing dislocation reactions we confirm the origin of the observed types of VDs, which can be efficiently distinguished by LACBED. The screw type VDs are formed by a reaction of perfect 60° dislocations, whereas the edge types are sessile dislocations that can be formed by cross-slips and climbing processes. The understanding of these origins allows us to suggest strategies to avoid VDs.

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