The Electric Field Very Near a Driven Cylindrical Antenna

Radio Science ◽  
1966 ◽  
Vol 1 (3) ◽  
pp. 353-360 ◽  
Author(s):  
Ronold W. P. King ◽  
Tai Tsun Wu
Keyword(s):  
Electric Field ◽  
Cylindrical Antenna

The Field in a Narrow Circumferential Slot in a Coaxial Waveguide

1973 ◽  
Vol 51 (9) ◽  
pp. 946-955 ◽  
Author(s):  
R. A. Hurd
Keyword(s):  
Electric Field ◽  
Outer Wall ◽  
Coaxial Waveguide ◽  
Input Admittance ◽  
Quantity Of Interest ◽  
Cylindrical Antenna

The first three terms in the expansion of the electric field in a narrow circumferential gap in the outer wall of a coaxial waveguide have been determined. Also found is the input admittance of an infinite, coaxially fed cylindrical antenna, a quantity of interest in the theory of sleeve antennas.

scholarly journals An Efficient Deterministic-Stochastic Model of the Human Body Exposed to ELF Electric Field

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Anna Šušnjara ◽  
Dragan Poljak
Keyword(s):  
Electric Field ◽  
Stochastic Model ◽  
Human Body ◽  
Low Frequency ◽  
Stochastic Approach ◽  
Axial Current ◽  
The Body ◽  
Cylindrical Antenna ◽  
New Perspective ◽  
Mean Trend

The paper deals with the deterministic-stochastic model of the human body represented as cylindrical antenna illuminated by a low frequency electric field. Both analytical and numerical (Galerkin-Bubnov scheme of Boundary Element Method) deterministic solutions of the problem are outlined. This contribution introduces the new perspective of the problem: the variability inherent to input parameters, such as the height of the body, the shape of the body, and the conductivity of body tissue, is propagated to the output of interest (induced axial current). The stochastic approach is based on the stochastic collocation (SC) method. Computational examples show the mean trend of both analytically and numerically computed axial current with the confidence margins for different set of input random variables. The results point out the possibility of improving the efficiency in calculation of basic restriction parameter values in electromagnetic dosimetry.

INFINITE PLANAR AND COLLINEAR ARRAYS OF CYLINDRICAL ANTENNAS

1967 ◽  
Vol 45 (9) ◽  
pp. 3107-3117 ◽  
Author(s):  
A. L. VanKoughnett
Keyword(s):  
Boundary Condition ◽  
Electric Field ◽  
Field Variation ◽  
Algebraic Equations ◽  
Planar Arrays ◽  
Cylindrical Antenna ◽  
Electric Field Variation ◽  
Cylindrical Antennas ◽  
Active Impedance ◽  
Infinite Planar

The active impedance and current distribution on a cylindrical antenna in a uniform, infinite, planar or collinear array are examined. A Fourier series for the antenna current is derived by relating the electric field variation in the gaps between adjacent collinear elements to the current. The electric field in the gaps is expanded in a series of Chebyshev polynomials whose coefficients are found by solving the set of algebraic equations obtained by enforcing at a number of points the boundary condition that the current vanish in the gaps between the ends of adjacent elements. The analysis is suitable for any combination of element length and scan angle, provided that the distance between the ends of adjacent collinear elements is comparable to or less than the element length. Results are compared with those based upon sinusoidally distributed currents and discrepancies are noted for arrays with closely spaced collinear elements and for wide H-plane scan angles of planar arrays.

Resolution in photoelectron microscopy

1991 ◽  
Vol 49 ◽  
pp. 458-459
Author(s):  
G. F. Rempfer
Keyword(s):  
Electron Microscopy ◽  
Electric Field ◽  
Ultraviolet Light ◽  
Uniform Field ◽  
Virtual Image ◽  
Lens System ◽  
Photoemission Electron Microscopy ◽  
Planar Electrode ◽  
Electron Lens ◽  
Photoemission Electron

In photoelectron microscopy (PEM), also called photoemission electron microscopy (PEEM), the image is formed by electrons which have been liberated from the specimen by ultraviolet light. The electrons are accelerated by an electric field before being imaged by an electron lens system. The specimen is supported on a planar electrode (or the electrode itself may be the specimen), and the accelerating field is applied between the specimen, which serves as the cathode, and an anode. The accelerating field is essentially uniform except for microfields near the surface of the specimen and a diverging field near the anode aperture. The uniform field forms a virtual image of the specimen (virtual specimen) at unit lateral magnification, approximately twice as far from the anode as is the specimen. The diverging field at the anode aperture in turn forms a virtual image of the virtual specimen at magnification 2/3, at a distance from the anode of 4/3 the specimen distance. This demagnified virtual image is the object for the objective stage of the lens system.

Field-assisted ionization theory for microscopists

1994 ◽  
Vol 52 ◽  
pp. 820-821
Author(s):  
Patrick P. Camus
Keyword(s):  
Electric Field ◽  
Electron Tunneling ◽  
Ionization Probability ◽  
Critical Distance ◽  
Tunneling Probability ◽  
Field Ionization ◽  
Radius Of Curvature ◽  
Field Evaporation ◽  
A Value ◽  
Ion Emission

The theory of field ion emission is the study of electron tunneling probability enhanced by the application of a high electric field. At subnanometer distances and kilovolt potentials, the probability of tunneling of electrons increases markedly. Field ionization of gas atoms produce atomic resolution images of the surface of the specimen, while field evaporation of surface atoms sections the specimen. Details of emission theory may be found in monographs.Field ionization (FI) is the phenomena whereby an electric field assists in the ionization of gas atoms via tunneling. The tunneling probability is a maximum at a critical distance above the surface,xc, Fig. 1. Energy is required to ionize the gas atom at xc, I, but at a value reduced by the appliedelectric field, xcFe, while energy is recovered by placing the electron in the specimen, φ. The highest ionization probability occurs for those regions on the specimen that have the highest local electric field. Those atoms which protrude from the average surfacehave the smallest radius of curvature, the highest field and therefore produce the highest ionizationprobability and brightest spots on the imaging screen, Fig. 2. This technique is called field ion microscopy (FIM).

Linear growth of instabilities on a liquid metal under normal electric field

1993 ◽  
Vol 3 (8) ◽  
pp. 1201-1225 ◽  
Author(s):  
G. N�ron de Surgy ◽  
J.-P. Chabrerie ◽  
O. Denoux ◽  
J.-E. Wesfreid
Keyword(s):  
Liquid Metal ◽  
Electric Field ◽  
Linear Growth ◽  
Normal Electric Field
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