Penetration Of Electromagnetic Field Research Articles

Electromagnetic Field Penetration into a Cylindrical Cavity

For an E-polarized plane wave incident on a perfectly conducting cylindrical shell having a longitudinal slit aperture, the fields inside the cavity are determined by a numerical solution of the E-field integral equation. Selected data are presented and the first few complex frequency (SEM) singularities are determined for a variety of aperture sizes.

The anomalous skin effect in a cylindrical mercury arc plasma

The penetration of a radio frequency electromagnetic field into a mercury arc plasma has been measured. The radial variation of the field amplitude with a hot plasma theory recently developed for cylindrical plasmas.

Electromagnetic coupling to a cable through apertures

Electromagnetic field penetration through apertures is investigated numerically and experimentally. The coupling to a cable located behind an aperture is determined in terms of the open circuit voltage of the cable. A square and a circular aperture are taken as examples, and the open circuit voltage is calculated and verified by an experiment. The apertures are modeled by employing Babinet's principle and solving the complementary flat plate problem using wire-grid modeling. Comparisons with radar cross section measurements were also made to verify the wire-grid modeling.

Penetration of an electromagnetic field through metal

Penetration of an electromagnetic field through metal

Electromagnetic Field Penetration into a Spherical Cavity

A plane wave is symmetrically incident on a spherical shell with a circular aperture. The fields inside and outside the cavity are expanded in terms of spherical vector wave functions and the modal coefficients are found by application of the least squares method to the boundary conditions. Computed data are obtained and the results exhibited in the form of amplitude curves of the interior and aperture fields as functions of position for a variety of cavity and aperture sizes. Within the cavity it appears that the field variations are primarily determined by the cavity size and that the aperture size serves only to scale them.

Anomalous skin effect for a plasma column in a magnetic field

The influence of a steady axial magnetic field on the anomalous penetration of low frequency electromagnetic fields into a cylindrical plasma column is investigated by considering a plasma with a Gaussian electron density distribution. For this model, a complete solution is obtained for Boltzmann's equation coupled to Maxwell's equations, and the fields calculated exactly. The results show dramatic changes of the internal fields for small changes of the applied magnetic field when the average Lamour radius of the electrons is of the order of the plasma radius.

Electromagnetic Pulse Penetration Through Small Apertures

The electromagnetic field penetration through small apertures is discussed for general aperture shapes. Approximnate analytical expressions are obtained for the penetration fields. In particular the fields that penetrate a small aperture into the region between two parallel, perfectly conducting plates are determined and some numerical results are obtained.

High frequency electromagnetic field in plasma with negative dielectric constant

A nonlinear mechanism is considered for the penetration of a transverse electromagnetic field into plasma with E=1- omega 02<0 and Te>>Ti. It is shown that the modulated finite amplitude electromagnetic wave produces plasma density fluctuations which form an electro-acoustic wave and transmits the electromagnetic field into the plasma with a velocity of the order of that ion sound. A theory describing the formation and evolution of the electroacoustic waves is developed.

Inhomogeneous Plasmas: On the Reflection and Transmission of Fields of Arbitrary Polarization

One objective of this paper is to develop a simple numerical procedure to determine the electromagnetic field penetration through a slab many hundreds of wavelengths in thickness of cold plasma with collisions. The electron-density-collision frequency profiles may be arbitrary but must contain only a finite number of discontinuities. The solution of this problem leads to a differential equation of the Riccati type. Other objectives are to evaluate exactly the transmission loss through the aforementioned inhomogeneous plasma and to determine the field variation within the plasma slab when the incident field is of arbitrary polarization. This is accomplished by solving the E and H plane incidence problems separately and then employing superposition. The results are in the form of an integral involving the reflection coefficient. The differential equations for the reflection coefficient and the transmission integrals are easily evaluated to practically any desired degree of accuracy by computer. Analytical and numerical results are presented for a plasma half-space with an exponential electron-density distribution.

Shielding of low frequency E.M. radiation by a bounded plasma in a magnetic field

The penetration of electromagnetic fields into a plasma slab with conducting boundaries when omega << omega p, omega << omega c ( omega being the oscillation frequency of the fields, omega p the plasma frequency and omega c the electron cyclotron frequency) is considered. Under these conditions the shielding properties of the plasma depend strongly on the ratio of the electron Larmor radius to the thickness of the plasma slab as well as on the electron density in the plasma.

Аномальное проникновение электромагнитного поля в металл и радиочастотные размерные эффекты

Аномальное проникновение электромагнитного поля в металл и радиочастотные размерные эффекты

Penetration of Electromagnetic Fields through Superconducting Films

Penetration of Electromagnetic Fields through Superconducting Films