Numerical study of the electrostatic field gradients present in various planar emitter field emission configurations relevant to experimental research

2005 ◽  
Vol 23 (2) ◽  
pp. 645 ◽  
Author(s):  
Adolfo González-Berríos ◽  
Fabrice Piazza ◽  
Gerardo Morell
Keyword(s):  
Field Emission ◽  
Experimental Research ◽  
Electrostatic Field ◽  
Numerical Study ◽  
Field Gradients

scholarly journals Wire Melt Electrospinning of Thin Polymeric Fibers via Strong Electrostatic Field Gradients

2018 ◽  
Vol 304 (1) ◽  
pp. 1800417 ◽  
Author(s):  
Kai Morikawa ◽  
Aniruddh Vashisth ◽  
Christian J. Grimme ◽  
Micah J. Green ◽  
Mohammad Naraghi
Keyword(s):  
Electrostatic Field ◽  
Polymeric Fibers ◽  
Field Gradients ◽  
Melt Electrospinning

Control of electrostatic field localization in field-emission structures

2011 ◽  
Vol 37 (4) ◽  
pp. 336-339 ◽  
Author(s):  
N. P. Aban’shin ◽  
B. I. Gorfinkel’ ◽  
A. N. Yakunin
Keyword(s):  
Field Emission ◽  
Electrostatic Field ◽  
Field Localization

A miniature, all-electrostatic, field emission electron column for surface analytical microscopy

1997 ◽  
Vol 8 (5) ◽  
pp. 536-545 ◽  
Author(s):  
R H Roberts ◽  
M M El Gomati ◽  
J Kudjoe ◽  
I R Barkshire ◽  
S J Bean ◽  
...  
Keyword(s):  
Field Emission ◽  
Electrostatic Field ◽  
Emission Electron ◽  
Analytical Microscopy

scholarly journals The new design of the wood stove based on the numerical analysis and experimental research

2020 ◽  
Vol 154 ◽  
pp. 04001
Author(s):  
Przemysław Motyl ◽  
Marcin Wikło ◽  
Julita Bukalska ◽  
Bartosz Piechnik ◽  
Rafał Kalbarczyk
Keyword(s):  
Fluid Flow ◽  
Heat Exchange ◽  
Numerical Analysis ◽  
Heat Release ◽  
Experimental Research ◽  
Numerical Study ◽  
Combustion Process ◽  
Small Scale ◽  
Wood Stove ◽  
Wood Stoves

In Europe, especially in Poland, wood-fired stoves remain one of the most popular renewable household heating. The use of wood logs in small-scale units stoves are expected to increase substantially. The work proposes a comprehensive approach to modify the design of wood stoves with heating power up to 20 kW, including design works, simulations, and experimental research. The article also presents the numerical study of a combustion process including fluid flow, chemical combustion reaction, and heat exchange in the wood stove. The retrofit enhanced a more stable heat release from the wood stove, which increased efficiency and reduction of the harmful components of combustion.

scholarly journals Numerical Study of Electrostatic Field Distortion on LPTPC End-Plates based on Bulk Micromegas Modules

2018 ◽  
Vol 174 ◽  
pp. 06007
Author(s):  
Purba Bhattacharya ◽  
Deb Sankar Bhattacharya ◽  
Supratik Mukhopadhyay ◽  
Nayana Majumdar ◽  
Sudeb Bhattacharya ◽  
...  
Keyword(s):  
Electrostatic Field ◽  
Linear Collider ◽  
Numerical Study ◽  
Superconducting Magnet ◽  
Simulation Framework ◽  
Test Beam ◽  
Field Distortion ◽  
Signal Sensitivity ◽  
Micro Pattern ◽  
First Time

The R&D activities for the linear collider TPC (LC-TPC) are currently working on the adoption of the micro pattern devices for the gaseous amplification stage. Several beam tests have been carried out at DESY with a 5 GeV electron beam in a 1 T superconducting magnet. We worked on a large prototype TPC with an end-plate that was built, for the first time, using seven resistive bulk Micromegas modules. During experiments, reduced signal sensitivity was observed at the boundary of these modules. Electrostatic field distortion near the module boundaries was considered to be the possible major reason behind these observations. In the present work, we will explore this hypothesis through numerical simulation. Our aim has been to understand the origin of distortions observed close to the edges of the test beam modules and to explore the possibility of using the Garfield simulation framework for investigating a phenomenon as complex as distortion.

Low-Voltage Scanning Electron Microscope (LVSEM) with a Single-Polepiece Lens

1990 ◽  
Vol 48 (1) ◽  
pp. 398-399
Author(s):  
I. Müllerová ◽  
M. Lenc
Keyword(s):  
Field Emission ◽  
Electrostatic Field ◽  
Beam Energy ◽  
Semiconductor Detector ◽  
Low Voltage ◽  
Primary Beam ◽  
Resolution Limit ◽  
Magnetic Lens ◽  
Angular Density ◽  
Cathode Lens

The advantages of the LV SEM are well known. Recently a lot of interesting results from this field were presented which were obtained thanks to development of field emission guns and to the enourmous progress in the computation techniques in electron optics.One of the simplest arrangements of the LVSEM is shown in Figure 1. The Tesla SEM BS 350 with a field emission gun and the TF-W/100-Zr cathode was used for our experiment. The gun provides 10−10 A current in the diffraction limited spot (for the angular density 0.20mA sr−1). If a potential Usp is applied to the specimen the energy E of the electrons that strike the specimen is Ep-eUsp (Ep-primary beam energy, e-elementary charge). The produced secondary (SE) and backscattered (BSE) electrons are accelerated towards the semiconductor detector by the electrostatic field and their energy spectrum extends from eUsp to Ep. The final energy of the SE and BSE can then be sufficient for achieving a reasonable amplification of the semiconductor detector which is directly proportional to the energy of the electrons that strike the detector. We calculated optical properties for a combination of the electrostatic and magnetic lenses of the basic geometry shown in Figure 1 and for an arrangement with the single polepiece lens shown in Figure 2. We particularly investigated coefficients of the chromatic (Cc) and spherical (Cs) aberrations as functions of the ratio of the primary beam energy to the energy of the electrons that strike the specimen Ep/E for some optimum position of the specimen, electropstatic and magnetic field. Our results are shown in Table 1. The coefficients Cs and Cc do not change with the energy Epor E if the ratio Ep/E is maitained the same and aberrations are lower for larger ratios Ep/E, so that the influence of the contribution of the electrostatic lens aberrations is negligible for our geometry. For example, if we require a resolution limit r=2nm and an energy of the electrons that strike the specimen E=300eV, it is possible to calculate that the coefficient of the aberrations must be Cs<0.21mm and Cc<0.14mm for an energy width AE=0.2eV, so that we need the ratio Ep/E≥150 for the arrangement shown in Figure 1 (i.e.Ep≥45keV) and Ep/E≥33 for the arrangement shown in Figure 2 (i.e.Ep≥10keV).The advantages of the combination of the magnetic lens with the electrostatic cathode lens for the high resolution very low energy electron microscopy are well known . We assume that for the LVSEM only a medium electrostatic field strength is admitted at the specimen surface. Nevertheless, our experimental arrangements should certainly be optimized in the future.

Study on the Effect upon Wear of Steel Ball from Injection Pressure in Reinforced Grinding Processing

2014 ◽  
Vol 915-916 ◽  
pp. 189-192
Author(s):  
Jin Rui Xiao ◽  
Xiao Chu Liu ◽  
Bi Hong Xie ◽  
Jian Wen Zhang ◽  
Jun Huang ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Surface Morphology ◽  
Field Emission ◽  
Experimental Research ◽  
Injection Pressure ◽  
Steel Ball ◽  
Emission Electron

An experiment is used to research the influence of injection stress towards the wear of steel ball in reinforced grinding processing under the setting condition. The field-emission electron microscope is used to obverse the samples surface morphology and the phonology equipment of surface morphology is used to measure the surface morphology of samples. The surface of the steel ball wear degree is analyzed by the surface morphology indirectly. Experimental research shows that in the condition of setting experiment, the injection pressure of reinforced grinding should not lager than 0.6MPa. If not, the obvious wear will appear in the surface of steel ball and the disadvantageous influence will happen, such as scratching the surface of workpiece under processing.

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