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.

Novel features of electromagnetic waves in an isotropic degenerate electron-ion plasma

2021 ◽  
Author(s):  
P. Maryam ◽  
Rozina Chaudhary ◽  
Shahid Ali ◽  
Hassan Amir Shah ◽  
Stefaan Poedts
Keyword(s):  
Nonlinear Interaction ◽  
Electromagnetic Waves ◽  
Tunneling Effect ◽  
Fermi Velocity ◽  
Degenerate Electron ◽  
Linear Dispersion ◽  
Direct Function ◽  
Ion Plasma ◽  
Damping Rate ◽  
Electron Quantum

Abstract Within the framework of kinetic theory, the nonlinear interaction of electromagnetic waves (EMWs) with a degenerate electron-ion plasma is studied to account for the electron quantum mechanical effects. For this purpose, a specific quantum regime is considered, for which the degenerate electron Fermi velocity is assumed to be taken of the order of group velocity of EMWs. This eventually leads to the existence of nonlinear Landau damping rate for the EMWs in the presence of electron Ponderomotive force. The electrons-ion density oscillations may be arisen from the nonlinear interaction of EMWs, leading to a new type of nonlinear Schrödinger equation in terms of a complex amplitude for electromagnetic pump wave. The profiles of nonlinear damping rate reveal that EMWs become less damped for increasing the quantum tunnelling effects. The electrostatic response for the linear electrostatic waves is also investigated and derived a linear dispersion for the ion-acoustic damping rate. The latter is a direct function of electron Fermi speed and does not rely on the Bohm tunneling effect. The obtained results are numerically analyzed for the two microwaves of different harmonics in the context of nonrelativistic astrophysical dense plasma environments, e.g., white dwarfs, where the electron quantum corrections cannot be ignored.

scholarly journals High Photocurrent Density and Continuous Electron Emission Characterization of a Multi-Alkali Antimonide Photocathode

Electronics ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 1991
Author(s):  
Jun Dai ◽  
Yikun Ding ◽  
Cunjun Ruan ◽  
Xiangyan Xu ◽  
Hulin Liu
Keyword(s):  
Electric Fields ◽  
Current Density ◽  
Electron Emission ◽  
Continuous Wave ◽  
High Current Density ◽  
Optical Power ◽  
Photocurrent Density ◽  
Maximum Current ◽  
Section Electron

High photocurrent density cathodes that enable small cross-section electron beams are required for high-power terahertz vacuum devices. Multi-alkali antimonide photocathodes may be well suited for generating sub-mm electron beam sources. This paper involves the repeatability, stability, uniformity, and linearity experiments of the multi-alkali antimonide photocathodes electron emission operations under a continuous-wave 450 nm laser with a bias voltage of 5000 V. The effect of heat, electric contact, and cathode surface roughness to emission characterizations is analyzed. The methods to maintain the high-current-density emission and avoid the fatigue of the photocathode are verified. The emission can be repeated with increased optical power. The stable photocurrent density of near 1 A/cm2 and maximum current density of near 1.43 A/cm2 is recorded. The continuous photocurrent density is significantly improved compared to the current density reported in traditional applications. It is found that the current curves measuring at different areas of the photocathode differ greatly after the laser power of 800 mW. The increase in current for some areas may be attributed to the conductive current caused by built-in electric fields between the emission rough area and its adjacent areas.

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.

The Field Emission of Globe-Like Diamond Microcrystalline Aggregate Films

2011 ◽  
Vol 279 ◽  
pp. 88-92
Author(s):  
Jin Hai Gao ◽  
Wu Qing Zhang ◽  
Zhen Li
Keyword(s):  
Field Emission ◽  
Electric Fields ◽  
Current Density ◽  
Microwave Plasma ◽  
Chemical Vapor ◽  
Chemical Vapor Deposition Method ◽  
Emission Properties ◽  
Plasma Chemical Vapor Deposition ◽  
Field Emission Properties ◽  
Turn On

The globe-like diamond microcrystalline aggregates films were fabricated by microwave plasma chemical vapor deposition method. The field emission properties and emission stability of the films were tested using a diode structure in vacuum. It was found that the globe-like diamond microcrystalline aggregates films exhibited good electron emission properties and stability. The turn-on field of 0. 55 V /μm and the current density of 11mA/cm2 at the electric fields of 2.73V/μm were obtained. At the successive operator circles, the turn-on field tends to stabilize at 1. 08V /μm and the current density of 6.6 mA/cm2 is obtained.

Nonlinear interaction of intense electromagnetic waves with a magnetoactive electron-positron-ion plasma

2013 ◽  
Vol 20 (8) ◽  
pp. 082123 ◽  
Author(s):  
S. M. Khorashadizadeh ◽  
E. Rastbood ◽  
H. Zeinaddini Meymand ◽  
A. R. Niknam
Keyword(s):  
Nonlinear Interaction ◽  
Electromagnetic Waves ◽  
Ion Plasma ◽  
Electron Positron
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