Simulation Study of the Effect of CNT Geometric Characteristics on the Electric Field Enhancement Factor

2012 ◽  
Vol 62 (3) ◽  
pp. 294
Author(s):  
Tae Dong Lee ◽  
Seong Ryong Ryu
Keyword(s):  
Electric Field ◽  
Simulation Study ◽  
Enhancement Factor ◽  
Field Enhancement ◽  
Field Enhancement Factor ◽  
Electric Field Enhancement ◽  
Geometric Characteristics

scholarly journals Distribution of earth atmospheric electric field in the vicinity of the vehicles for transport petroleum derivates

2006 ◽  
Vol 19 (2) ◽  
pp. 189-196 ◽  
Author(s):  
Alenka Milovanovic
Keyword(s):  
Electric Field ◽  
Human Body ◽  
Enhancement Factor ◽  
Field Enhancement ◽  
Field Enhancement Factor ◽  
Atmospheric Electric Field ◽  
Electric Field Enhancement ◽  
Petrol Station ◽  
Electrode Method ◽  
Petrol Pump

In this paper using Equivalent Electrode Method (EEM) Atmospheric Electric Field (AEF) distribution in the vicinity of the cargo vehicle is approximately numerically determined, when the vehicles are situated on petrol station near by petrol pump and people. The petrol pump is always grounded, but human body and vehicle are treated as grounded or 'floating' electrodes. Several results of electric field enhancement factor for the vehicle including maps of equienergetic curves are presented.

scholarly journals ELECTRIC FIELD ENHANCEMENT FACTORS AROUND A METALLIC, END-CAPPED CYLINDER

NANO ◽  
2006 ◽  
Vol 01 (01) ◽  
pp. 87-93 ◽  
Author(s):  
S. PODENOK ◽  
M. SVENINGSSON ◽  
K. HANSEN ◽  
E. E. B. CAMPBELL
Keyword(s):  
Carbon Nanotubes ◽  
Electric Field ◽  
Local Field ◽  
Enhancement Factor ◽  
Field Enhancement ◽  
Field Enhancement Factor ◽  
Electric Field Enhancement ◽  
Enhancement Factors ◽  
Plane Capacitor ◽  
Metallic Cylinder

We have calculated the electric field enhancement factor for a metallic cylinder with a hemispherical end-cap in a plane capacitor geometry paying particular attention to the dependence of the field enhancement factor on the anode distance. In addition, we have investigated the angular dependence of the local field at the end-cap. The numerical results, which cover a range of different ratios of cylinder lengths and anode distances, can be fitted with simple functional expressions which provide a useful scaling for calculations of field emission currents from closed cap carbon nanotubes or nanowires.

scholarly journals Study on surface enhanced Raman scattering of Au and Au@Al2O3 spherical dimers based on 3D finite element method

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Bao-xin Yan ◽  
Yan-ying Zhu ◽  
Yong Wei ◽  
Huan Pei
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Electric Field ◽  
Raman Scattering ◽  
Enhancement Factor ◽  
Field Enhancement ◽  
Electric Field Enhancement ◽  
Surface Enhanced ◽  
Surface Enhanced Raman ◽  
Enhanced Raman Scattering

AbstractIn this paper, the surface enhanced Raman scattering (SERS) characteristics of Au and Au@Al2O3 nanoparticle dimers were calculated and analyzed by using finite element method (3D-FEM). Firstly, the electric field enhancement factors of Au nanoparticles at the dimer gap were optimized from three aspects: the incident angle of the incident light, the radius of nanoparticle and the distance of the dimer. Then, aluminum oxide is wrapped on the Au dimer. What is different from the previous simulation is that Al2O3 shell and Au core are regarded as a whole and the total radius of Au@Al2O3 dimer is controlled to remain unchanged. By comparing the distance of Au nucleus between Au and Au@Al2O3 dimer, it is found that the electric field enhancement factor of Au@Al2O3 dimer is much greater than that of Au dimer with the increase of Al2O3 thickness. The peak of electric field of Au@Al2O3 dimer moves towards the middle of the resonance peak of the two materials, and it is more concentrated than that of the Au dimer. The maximum electric field enhancement factor 583 is reached at the shell thickness of 1 nm. Our results provide a theoretical reference for the design of SERS substrate and the extension of the research scope.

scholarly journals Study on Surface Enhanced Raman Scattering of Au and Au@Al2O3 Spherical Dimers Based on 3D Finite Element Method

2020 ◽  
Author(s):  
Baoxin Yan ◽  
Yanying Zhu ◽  
Yong Wei ◽  
Huan Pei
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Electric Field ◽  
Enhancement Factor ◽  
Field Enhancement ◽  
Electric Field Enhancement ◽  
Surface Enhanced ◽  
Surface Enhanced Raman ◽  
Enhanced Raman Scattering ◽  
Peak Electric Field

Abstract In this paper, the surface enhanced Raman scattering (SERS) characteristics of Au and Au@Al2O3 nanoparticle dimers were calculated and analyzed by using finite element method (3D-FEM). Firstly, the electric field enhancement factors of Au nanoparticles at the dimer gap were optimized from three aspects: the incident angle of the incident light, the radius of nanoparticle and the distance of the dimer. Then, aluminum oxide is wrapped on the Au dimer. What is different from the previous simulation is that Al2O3 shell and Au core are regarded as a whole and the total radius of Au@Al2O3 dimer is controlled to remain unchanged. By comparing the distance of Au nucleus between Au and Au@Al2O3 dimer, it is found that the electric field enhancement factor of Au@Al2O3 dimer is much greater than that of Au dimer with the increase of Al2O3 thickness. The peak electric field of Au@Al2O3 dimer moves towards the middle of the resonance peak of the two materials, but the peak electric field of Au dimer is more concentrated than that of Au dimer, so that the excitation wavelength has less influence on Raman enhancement. The maximum electric field enhancement factor 583 is reached at the shell thickness of 1 nm. Our results provide a theoretical reference for the design of SERS substrate and the extension of the research scope.

scholarly journals Studies of enhanced field emission relevant to high field superconducting radio frequency devices

2021 ◽  
pp. 7-7
Author(s):  
Marija Radmilovic-Radjenovic ◽  
Zeljka Nikitovic ◽  
Ranislav Radjenovic
Keyword(s):  
Electric Field ◽  
Radio Frequency ◽  
Field Emission ◽  
Enhancement Factor ◽  
Field Enhancement ◽  
Field Enhancement Factor ◽  
Accurate Estimation ◽  
Cavity Surface ◽  
Planar Surfaces ◽  
Superconducting Radio Frequency

Surface roughness represents the measure of the irregularities on the surface contributing to the local field enhancement. The traditional Fowler-Nordheim equation established for perfectly planar surfaces is not suitable for describing emission from rough surfaces. Instead, it is more appropriate to use the equation that accounts for the field enhancement factor describing the effect of the surface morphology. In superconducting radio frequency cavities field emission may occur in the irises and the tips on the cavity surface may act as an emitter leading to the high electric field. For this study, calculations for hemispherical, cylindrical, and conical tips have been performed by using a multiphysics software package COMSOL. The focus was put on the dependence of the field enhancement factor on the shape and the radius of the protrusions. The electric field strength and the current density increase with increasing the root mean square average of the profile heights due to field enhancement at the cavity irises. The lowest value of the electric field has been achieved for the hemisphere. The calculated values for the field enhancement factors are consistent with the data from the literature, in which case the protrusion may represent a small local bump on the surface of a superconducting cavity. Based on the fit of the results, presented here, the relation between the enhancement factor and the radius has been suggested. The accurate estimation of the field emission may play a crucial role in the design of accelerators and other technological applications with requirements of very high precision.

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