Electric fields and electromagnetic waves

1981 ◽  
Vol 19 (1) ◽  
pp. 50-51 ◽  
Author(s):  
George A. Dulk ◽  
Robert Stoller
Keyword(s):  
Electric Fields ◽  
Electromagnetic Waves

MUTUAL NONLINEAR INTERACTION OF A NUMBER OF ELECTROMAGNETIC WAVES IN A PLASMA

1963 ◽  
Vol 41 (10) ◽  
pp. 1702-1711 ◽  
Author(s):  
Mahendra Singh Sodha ◽  
Carl J. Palumbo
Keyword(s):  
Wave Equation ◽  
Electric Fields ◽  
Current Density ◽  
Nonlinear Interaction ◽  
Electromagnetic Waves ◽  
Physical Significance ◽  
Mutual Interaction ◽  
Modulated Waves ◽  
Boltzmann's Equation ◽  
Uniform Plasma

In this communication the authors have obtained an expression for current density in a slightly ionized uniform plasma in the presence of a number of electric fields of different frequencies by solving the appropriate Boltzmann's equation. This expression along with the wave equation has been used to investigate the nonlinear mutual interaction of a number of electromagnetic waves, propagating in a plasma. Limitations of the present analysis have also been indicated and the physical significance of the results has been discussed. The technique has also been applied to investigate the mutual interaction of amplitude-modulated waves, and the results express a generalization of Luxembourg effect to a number of strong modulated waves.

WAVE PROPAGATION IN A CYLINDRICAL WAVE GUIDE CONTAINING INHOMOGENEOUS PLASMA INVOLVING A TURNING POINT

1963 ◽  
Vol 41 (1) ◽  
pp. 113-131 ◽  
Author(s):  
S. N. Samaddar
Keyword(s):  
Electric Fields ◽  
Electromagnetic Waves ◽  
Turning Point ◽  
Boundary Effect ◽  
Inhomogeneous Plasma ◽  
Simple Zero ◽  
Wave Guide ◽  
Wave Number ◽  
Axially Symmetric ◽  
Radial Wave

Propagation of axially symmetric E-type and H-type modes of electromagnetic waves in a radially inhomogeneous plasma inside a wave guide is considered. For E-type modes conditions for the propagation of slow surface waves along the plasma–dielectric interface have been obtained. Approximate expressions for fields for wavelengths much smaller than the ratio of the gradient of the permittivity to the permittivity of the plasma are also given.It is also shown that if the dielectric constant ε(r) of the plasma vanishes along a particular surface r = r0, the electromagnetic fields for E-type modes behave singularly along this surface. In particular, if ε(r) has a simple zero at r0 ≠ 0, the radial and the longitudinal electric fields become singular as 1/ε(r0) and log ε(r0) respectively at r0. On the other hand, if ε(r) has a multiple zero at r0, the singularities of the above-mentioned fields will be as strong as a multiple pole at r0.Turning-point phenomena are also observed when the radial wave number [Formula: see text] vanishes along a surface. It is shown that the fields are oscillatory in the region [Formula: see text] and evanescent in the region [Formula: see text] for both E-type and H-type modes. The treatment of the singular behavior of the fields at ε(r) = 0, and of the turning-point phenomena at [Formula: see text], does not consider any boundary effect; therefore the results obtained here will be valid also for an inhomogeneous plasma column in free space.

Discussions and Communications: Propagation of Transient Electromagnetic Waves in a Conducting Medium

Geophysics ◽  
1955 ◽  
Vol 20 (4) ◽  
pp. 959-961 ◽  
Keyword(s):  
Electric Field ◽  
Electric Fields ◽  
Electromagnetic Waves ◽  
Step Function ◽  
Conducting Medium ◽  
Initial Value ◽  
Transient Electromagnetic ◽  
Ramp Function

Wait (1951) has calculated the transient electric fields for several types of step-function current sources placed inside a conducting medium. Now any generated pulse will require a finite build-up time to reach its final magnitude from its initial value of zero. In most cases, this type of pulse may be very well approximated by a ramp-function pulse (Figure 1). Expressions for the electric field of this type of pulse will be deduced in the following analysis.

scholarly journals Thermal electron anisotropy driven by kinetic Alfven waves in the Earth's magnetotail

2020 ◽  
Author(s):  
Alexander Lukin ◽  
Anton Artemyev ◽  
Evgeny Panov ◽  
Rumi Nakamura ◽  
Anatoly Petrukovich ◽  
...  
Keyword(s):  
Electric Fields ◽  
Electromagnetic Waves ◽  
Alfven Waves ◽  
Alfvén Waves ◽  
Plasma Flows ◽  
Thermal Electron ◽  
Electron Population ◽  
Electron Field ◽  
Kinetic Alfvén Waves

Abstract. Thermal and subthermal electron populations in the Earth's magnetotail are usually characterized by pronounced field-aligned anisotropy that contributes to generation of strong electric currents within the magnetotail current sheet. Formation of this anisotropy requires electron field-aligned acceleration, and thus likely involves field-aligned electric fields. Such fields can be carried by various electromagnetic waves generated by fast plasma flows interacting with ambient magnetotail plasma. In this paper we consider one of the most intense observed wave emissions, kinetic Alfven waves, that often accompany fast plasma flows in the magnetotail. Using two tail seasons (2017, 2018) of MMS observations we have collected statistics of 80 fast plasma flows (or bursty bulk flows) events with distinctive enhancement of intensity of broadband electromagnetic waves (kinetic Alfven waves). We show correlation the intensity of electric fields of kinetic Alfven waves and characteristics of electron anisotropy distributions: the parallel electron anisotropy increases with magnitude of the wave parallel electric field. Also the energy range of this electron anisotropic population is well within the expected acceleration range for assumed kinetic Alfven waves. Our results indicate an important role of KAWs in production of thermal field-aligned electron population typically observed in the Earth's magnetotail.

scholarly journals High Power Electromagnetic Waves Exposure of Healthy and Tumor Bearing Mice: Assessment of Effects on Mice Growth, Behavior, Tumor Growth, and Vessel Permeabilization

2021 ◽  
Vol 22 (16) ◽  
pp. 8516
Author(s):  
Jelena Kolosnjaj-Tabi ◽  
Muriel Golzio ◽  
Elisabeth Bellard ◽  
Alexandre Catrain ◽  
Thomas Chretiennot ◽  
...  
Keyword(s):  
Pilot Study ◽  
Electric Fields ◽  
High Power ◽  
Electromagnetic Waves ◽  
Field Experiments ◽  
Narrow Band ◽  
Biological Effects ◽  
Wide Band ◽  
Tumor Bearing ◽  
Peak Value

High power radiofrequencies may transiently or permanently disrupt the functioning of electronic devices, but their effect on living systems remains unknown. With the aim to evaluate the safety and biological effects of narrow-band and wide-band high-power electromagnetic (HPEM) waves, we studied their effects upon exposure of healthy and tumor-bearing mice. In field experiments, the exposure to 1.5 GHz narrow-band electromagnetic fields with the incident amplitude peak value level in the range of 40 kV/m and 150 MHz wide-band electric fields with the amplitude peak value in the range of 200 kV/m, did not alter healthy and tumor-bearing animals’ growth, nor it had any impact on cutaneous murine tumors’ growth. While we did not observe any noticeable behavioral changes in mice during the exposure to narrow-band signals when wide-band HPEM signals were applied, mice could behave in a similar way as they respond to loud noise signals: namely, if a mouse was exploring the cage prior to signal application, it returned to companion mates when wide-band HPEM signals were applied. Moreover, the effect of wide-band signals was assessed on normal blood vessels permeability in real-time in dorsal-chamber-bearing mice exposed in a pilot study using wide-band signal applicators. Our pilot study conducted within the applicator and performed at the laboratory scale suggests that the exposure to wide-band signals with the amplitude of 47.5 kV/m does not result in increased vessel permeability.

The Plasma Wave Investigation (PWI) onboard the BepiColombo/MMO: First measurement of electric fields, electromagnetic waves, and radio waves around Mercury

2010 ◽  
Vol 58 (1-2) ◽  
pp. 238-278 ◽  
Author(s):  
Y. Kasaba ◽  
J.-L. Bougeret ◽  
L.G. Blomberg ◽  
H. Kojima ◽  
S. Yagitani ◽  
...  
Keyword(s):  
Plasma Wave ◽  
Electric Fields ◽  
Electromagnetic Waves ◽  
Radio Waves

scholarly journals Evaluations of Acute and Sub-Acute Biological Effects of Narrowband and Moderate-Band High Power Electromagnetic Waves on Cellular Spheroids

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Laure Gibot ◽  
Jelena Kolosnjaj-Tabi ◽  
Elisabeth Bellard ◽  
Thomas Chretiennot ◽  
Quentin Saurin ◽  
...  
Keyword(s):  
Electric Fields ◽  
High Power ◽  
Electromagnetic Waves ◽  
Biological Effects ◽  
Membrane Integrity ◽  
Dermal Fibroblasts ◽  
Mitochondrial Potential ◽  
Cellular Spheroids ◽  
Physiological Processes ◽  
Electromagnetic Signals

Abstract High power electromagnetic signals can disrupt the functioning of electronic devices. As electromagnetism plays a role in cells homeostasis, such electromagnetic signals could potentially also alter some physiological processes. Herein we report on distinct biological parameters assessment after cellular spheroids exposure to high power electromagnetic signals, such as the ones used for defense applications. Signals effects were assessed in tumor cells spheroids and in normal human dermal fibroblasts spheroids, where macroscopic aspect, growth, plasma membrane integrity, induction of apoptosis, ATP content, and mitochondrial potential were investigated after spheroids exposure to high power electromagnetic signals. No significant effects were observed, indicating that 1.5 GHz narrowband electromagnetic fields with incident amplitude level of 40 kV/m, and 150 MHz moderate-band electric fields with an amplitude of 72.5 to approximately 200 kV/m, do not cause any significant alterations of assessed parameters.

Intense longitudinal electric fields generated from transverse electromagnetic waves

2004 ◽  
Vol 84 (19) ◽  
pp. 3855-3857 ◽  
Author(s):  
Godai Miyaji ◽  
Noriaki Miyanaga ◽  
Koji Tsubakimoto ◽  
Keiichi Sueda ◽  
Ken Ohbayashi
Keyword(s):  
Electric Fields ◽  
Electromagnetic Waves ◽  
Transverse Electromagnetic

scholarly journals Effects of multiple scatter on the propagation and absorption of electromagnetic waves in a field-aligned-striated cold magneto-plasma: implications for ionospheric modification experiments

2002 ◽  
Vol 20 (1) ◽  
pp. 41-55 ◽  
Author(s):  
T. R. Robinson
Keyword(s):  
Electric Fields ◽  
Plasma Density ◽  
Electromagnetic Waves ◽  
Broad Band ◽  
Radio Science ◽  
Multiple Scatter ◽  
Electromagnetic Test ◽  
Ionospheric Modification ◽  
Hybrid Resonance ◽  
Single Scatter

Abstract. A new theory of the propagation of low power electromagnetic test waves through the upper-hybrid resonance layer in the presence of magnetic field-aligned plasma density striations, which includes the effects of multiple scatter, is presented. The case of sinusoidal striations in a cold magnetoplasma is treated rigorously and then extended, in an approximate manner, to the broad-band striation spectrum and warm plasma cases. In contrast to previous, single scatter theories, it is found that the interaction layer is much broader than the wavelength of the test wave. This is due to the combined electric fields of the scattered waves becoming localised on the contour of a fixed plasma density, which corresponds to a constant value for the local upper-hybrid resonance frequency over the whole interaction region. The results are applied to the calculation of the refractive index of an ordinary mode test wave during modification experiments in the ionospheric F-region. Although strong anomalous absorption arises, no new cutoffs occur at the upper-hybrid resonance, so that in contrast to the predictions of previous single scatter theories, no additional reflections occur there. These results are consistent with observations made during ionospheric modification experiments at Tromsø, Norway.Key words. Ionosphere (active experiments; ionospheric irregularities) Radio science (ionospheric propagation)

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