scholarly journals Excitation of ion wakefields by electromagnetic pulses in dense plasmas

2009 ◽  
Vol 75 (1) ◽  
pp. 15-18 ◽  
Author(s):  
P. K. SHUKLA
Keyword(s):  
Wave Equation ◽  
Electromagnetic Wave ◽  
Electromagnetic Waves ◽  
Electromagnetic Pulse ◽  
Dense Plasma ◽  
Ponderomotive Force ◽  
Electromagnetic Pulses ◽  
Dense Plasmas ◽  
High Energies

AbstractThe excitation of electrostatic ion wakefields by electromagnetic pulses in a very dense plasma is considered. For this purpose, a wave equation for the ion wakefield in the presence of the ponderomotive force of the electromagnetic waves is obtained. Choosing a typical profile for the electromagnetic pulse, the form of the ion wakefields is deduced. The electromagnetic wave-generated ion wakefields can trap protons and accelerate them to high energies in dense plasmas.

scholarly journals Generation of magnetic fields by the ponderomotive force of electromagnetic waves in dense plasmas

2009 ◽  
Vol 76 (1) ◽  
pp. 25-28 ◽  
Author(s):  
P. K. SHUKLA ◽  
NITIN SHUKLA ◽  
L. STENFLO
Keyword(s):  
Electromagnetic Wave ◽  
Magnetic Fields ◽  
Electromagnetic Waves ◽  
Ponderomotive Force ◽  
Intense Laser ◽  
Quantum Plasma ◽  
Dense Plasmas ◽  
Solid Density ◽  
Astrophysical Objects ◽  
Density Plasma

AbstractWe show that the non-stationary ponderomotive force of a large-amplitude electromagnetic wave in a very dense quantum plasma with streaming degenerate electrons can spontaneously create d.c. magnetic fields. The present result can account for the seed magnetic fields in compact astrophysical objects and in the next-generation intense laser–solid density plasma interaction experiments.

scholarly journals Development and Preliminary Analysis of a VLF-Band Electromagnetic-Wave Observation System for Short-Term Earthquake Precursory Monitoring

2021 ◽  
Vol 9 ◽  
Author(s):  
Toshiyasu Nagao ◽  
Masashi Kamogawa ◽  
Jun Izutsu ◽  
Tomoyuki Suzuki ◽  
Airi Saito ◽  
...  
Keyword(s):  
Electromagnetic Wave ◽  
Data Storage ◽  
Electromagnetic Waves ◽  
Information Criterion ◽  
Observation System ◽  
Time Of Arrival ◽  
Electromagnetic Pulses ◽  
Observation Network ◽  
Inland Earthquake ◽  
Large Earthquakes

Preseismic VLF electromagnetic pulses occasionally increase a few days before large earthquakes, especially inland earthquakes. More than two decades ago, the Tokai University group developed a digital recording system for collecting the preseismic electromagnetic pulse data and showed remarkable results. However, due to the limitations of personal computers’ data storage and CPU power during that time, they discontinued the observation. We relaunched this research using current technology. This paper shows the development of the new observation system and presents preliminary results. In addition, we introduce an electromagnetic-wave arrival discrimination algorithm that combines the autoregressive model and the Akaike information criterion, which are commonly used for automatic waveform reading in seismology, to obtain accurate data on the time of arrival (TOA) of electromagnetic waves. Then, source positioning was performed using TOA of electromagnetic waves. Seven electromagnetic pulses near the epicenter were observed 2 days before the largest inland earthquake (M = 5.6) that occurred near the observation network during the observation period (2016–2020). These VLF pulses may be a seismic precursory phenomenon because they were not electromagnetic pulses originating from lightning. These results encourage future observations.

scholarly journals Absorption of Electromagnetic Waves in Non-Dispersive Plasma due to Effect of Ponderomotive Force

2020 ◽  
Vol 6 (1) ◽  
pp. 123-130
Author(s):  
P. K. Thakur ◽  
S. Bhaila ◽  
J. J. Nakarmi
Keyword(s):  
Electromagnetic Wave ◽  
Absorption Coefficient ◽  
Electromagnetic Waves ◽  
Unit Volume ◽  
Ponderomotive Force ◽  
Debye Length ◽  
Angular Frequency ◽  
Incident Laser ◽  
Electron Fluid

The absorption coefficient of electromagnetic wave propagating through overdense absorbing plasma is calculated by using Fresnel’s formula. Also, the force acting per unit volume of the electron fluid is calculated along z direction. The Fresnel’s formula is reduced in terms of conductivity and angular frequency so that nature of absorption coefficient with respect to conductivity of plasma and angular frequency of wave is studied, with the assumption that conductivity and angular frequency are two independent terms. By keeping conductivity of plasma constant, it is seen that the absorption coefficient is increased with increase in angular frequency and also absorption coefficient has the lowest value for the highest value of conductivity. At constant angular frequency of incidence, the absorption coefficient is decreased with increase in conductivity and also absorption coefficient has the highest value of angular frequency of incidence. Also the nature of force on the plasma is studied by considering that the conductivity of plasma is very large with compare to angular frequency of incident laser. The expression of absorption coefficient is separated into real and imaginary parts, and then plots are studied with respect to these parts. It is found that in both cases, the force on plasma is existed for short in time and distance, and then damps exponentially. Also, the variation of potential with distance is cleared that the potential is shielded within multiple distance of Debye length.

scholarly journals TRANSILLUMINATION OF THE DENSE PLASMA BARRIER BY THE STRONG BEAM OF ELECTROMAGNETIC WAVES: COMPUTER SIMULATION

2020 ◽  
pp. 64-68
Author(s):  
B.R. Mykhailenko ◽  
I.O. Anisimov
Keyword(s):  
Computer Simulation ◽  
Electromagnetic Wave ◽  
Software Package ◽  
Electromagnetic Waves ◽  
Dense Plasma ◽  
Wave Beam ◽  
Incident Beam ◽  
Strong Electromagnetic Wave ◽  
Higher Power ◽  
Simulation Results

Transillumination of a dense plasma barrier by a strong electromagnetic wave beam has been studied via simulation using the PIConGPU software package. Formation of the channel with reduced plasma density, predicted theoretically and detected experimentally, was observed. For a higher power incident beam, plasma turbulent dynamics has been observed, which leads to its "fast" transillumination. The simulation results didn’t confirm the theoretically proposed mechanisms of "fast" transillumination.

NONLINEAR PROPAGATION OF ELECTROMAGNETIC WAVES IN MAGNETOPLASMAS. II

1964 ◽  
Vol 42 (2) ◽  
pp. 349-363 ◽  
Author(s):  
Mahendra S. Sodha ◽  
Carl J. Palumbo
Keyword(s):  
Magnetic Field ◽  
Wave Equation ◽  
Electromagnetic Wave ◽  
Isotropic Medium ◽  
Electromagnetic Waves ◽  
Nonlinear Propagation ◽  
Complex Conductivity ◽  
Arbitrary Angle ◽  
Reflection And Refraction ◽  
The Magnetic Field

In this communication the authors have investigated the nonlinear propagation of an electromagnetic wave at an arbitrary angle to the direction of the magnetic field in a plasma. The authors have derived an expression for the complex conductivity tensor of a Lorentzian magnetoplasma, which is correct to terms involving the square of the amplitude of the electric vector. This expression, along with the wave equation, has been used to analyze two specific problems, viz. the propagation of an electromagnetic wave in an infinite magnetoplasma and reflection and refraction at the interface of a nonlinear magnetoplasma and a linear isotropic medium.

scholarly journals Magnetization of Rydberg plasmas by electromagnetic waves

2009 ◽  
Vol 76 (1) ◽  
pp. 19-23 ◽  
Author(s):  
J. T. MENDONÇA ◽  
NITIN SHUKLA ◽  
P. K. SHUKLA
Keyword(s):  
Electromagnetic Wave ◽  
Magnetic Fields ◽  
High Frequency ◽  
Large Amplitude ◽  
Electromagnetic Waves ◽  
Ponderomotive Force

AbstractIt is shown that the ponderomotive force of a large-amplitude electromagnetic wave in Rydberg plasmas can generate quasi-stationary magnetic fields. The present result can account for the origin of seed magnetic fields in the ultracold Rydberg plasmas when they are irradiated by the high-frequency electromagnetic wave.

Detection of delamination in composites by using electromagnetic penetrating radar

2014 ◽  
Vol 5 (2) ◽  
pp. 151-156
Author(s):  
Z. Mechbal ◽  
A. Khamlichi
Keyword(s):  
Electromagnetic Wave ◽  
Electromagnetic Waves ◽  
Electromagnetic Wave Propagation ◽  
Wave Reflection ◽  
Image Features ◽  
Partial Reflection ◽  
Straight Path ◽  
Reflected Signal ◽  
Short Time ◽  
Intervening Factors

Composites made from E-glass/epoxy or aramid/epoxy are frequently used in aircraft and aerospace industries. These materials are prone to suffer from the presence of delamination, which can reduce severely the performance of aircrafts and even threaten their safety. Since electric conductivity of these composites is rather small, they can propagate electromagnetic waves. Detection of delamination damage can then be monitored by using an electromagnetic penetrating radar scanner, which consists of emitting waves having the form of short time pulses that are centered on a given work frequency. While propagating, these waves undergo partial reflection when running into an obstacle or a material discontinuity. Habitually, the radar is moved at constant speed along a straight path and the reflected signal is processed as a radargram that gives the reflected energy as function of the two-way time and the antenna position.In this work, modeling of electromagnetic wave propagation in composites made from E-glass/epoxy was performed analytically. The electromagnetic wave reflection from a delamination defect was analyzed as function of key intervening factors which include the defect extent and depth, as well as the work frequency. Various simulations were performed and the obtained results have enabled to correlate the reflection pattern image features to the actual delamination defect characteristics which can provide quantification of delamination.

New Approach to the Theory of Circular Dichroism

1998 ◽  
Vol 63 (8) ◽  
pp. 1187-1201 ◽  
Author(s):  
Jaroslav Zamastil ◽  
Lubomír Skála ◽  
Petr Pančoška ◽  
Oldřich Bílek
Keyword(s):  
Electromagnetic Wave ◽  
Circular Dichroism ◽  
Electromagnetic Waves ◽  
Maxwell Equations ◽  
Optically Active ◽  
Semiclassical Approach ◽  
New Approach ◽  
Isotropic Media ◽  
New Formula ◽  
Circular Dichroïsm

Using the semiclassical approach for the description of the propagation of the electromagnetic waves in optically active isotropic media we derive a new formula for the circular dichroism parameter. The theory is based on the idea of the time damped electromagnetic wave interacting with the molecules of the sample. In this theory, the Lambert-Beer law need not be taken as an empirical law, however, it follows naturally from the requirement that the electromagnetic wave obeys the Maxwell equations.

scholarly journals Preparation and electromagnetic properties characterization of reduced graphene oxide/strontium hexaferrite nanocomposites

2020 ◽  
Vol 9 (1) ◽  
pp. 105-114 ◽  
Author(s):  
Shumin Du ◽  
Huaiyin Chen ◽  
Ruoyu Hong
Keyword(s):  
Electromagnetic Wave ◽  
Environmental Pollution ◽  
Electromagnetic Interference ◽  
Electromagnetic Waves ◽  
Rapid Development ◽  
Living Environment ◽  
World Health ◽  
Electromagnetic Properties ◽  
Strontium Hexaferrite ◽  
Wave Radiation

AbstractWith the rapid development of electronics and information technology, electronics and electrical equipment have been widely used in our daily lives. The living environment is full of electromagnetic waves of various frequencies and energy. Electromagnetic wave radiation has evolved into a new type of environmental pollution that has been listed by the WHO (World Health Organization) as the fourth largest source of environmental pollution after water, atmosphere, and noise. Studies have shown that when electromagnetic wave radiation is too much, it can cause neurological disorders. And electromagnetic interference will cause the abnormal operation of medical equipment, precision instruments and other equipment, and therefore cause incalculable consequences. Therefore, electromagnetic protection has become a hot issue of concern to the social and scientific circles.

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