scholarly journals Linear and nonlinear low-frequency collisional quantum Buneman Instability in electron-positron-ion Plasmas

2021 ◽  
Vol 49 (1) ◽  
Author(s):  
M. Nasir Khattak ◽  
◽  
U. Zakir ◽  
M. Yaqoob Khan ◽  
Niaz. Wali ◽  
...  
Keyword(s):  
Low Frequency ◽  
Coulomb Systems ◽  
Nonlinear Problems ◽  
Momentum Equation ◽  
Quantum Plasma ◽  
Potential Term ◽  
Quantum Hydrodynamic Model ◽  
Bohm Potential ◽  
Linear And Nonlinear ◽  
Quantum Limits

The linear and nonlinear low-frequency collisional quantum Buneman instability in electronpositron- ion plasmas have been studied. Buneman instability in low frequency three species quantum plasma has been investigated using the approach of the quantum hydrodynamic model. The one-dimensional low-frequency collisional model is revisited by introducing the Bohm potential term in the momentum equation along with the role of the positron. Low-frequency Buneman instability which arises by one stream of particles drifting over another is investigated in the presence of the positron. Different plasma configurations based on the relative velocities of streaming particles are analyzed and it is observed that positron content enhances the instability in classical limits. Further, we found that in pure quantum limits the instability growth rate is decreased by increasing the positron concentration. The present work is very useful for the nonlinear problems in Quantum Coulomb systems.

Laser beam guiding in partially stripped magnetized quantum plasma

Laser Physics ◽  
2021 ◽  
Vol 32 (1) ◽  
pp. 016002
Author(s):  
Punit Kumar ◽  
Nisha Singh Rathore
Keyword(s):  
Laser Beam ◽  
Spot Size ◽  
Quantum Plasma ◽  
Beam Power ◽  
Linear Wave ◽  
Linear Wave Equation ◽  
Quantum Hydrodynamic Model ◽  
Bohm Potential ◽  
Expansion Technique ◽  
Linearly Polarized

Abstract Relativistic and ponderomotive nonlinearities arising by the passage of a linearly polarized laser beam through a partially stripped magnetized quantum plasma are analyzed. The interaction formalism has been developed using the recently developed quantum hydrodynamic model. The effects associated with the Fermi pressure, quantum Bohm potential and electron spin have been incorporated. A nonparaxial, non-linear wave equation has been obtained by the use of source dependent expansion technique and spot size has been evaluated. The nonlinear relativistic self-focusing tends to focus the beam while the ponderomotive nonlinearity tends to defocus. The effect of magnetization and quantum effects on the spot size and the beam power have been studied.

scholarly journals Conversion efficiency of even harmonics of whistler pulse in quantum magnetoplasma

2019 ◽  
Vol 37 (01) ◽  
pp. 5-11
Author(s):  
Punit Kumar ◽  
Shiv Singh ◽  
Nafees Ahmad
Keyword(s):  
Magnetic Field ◽  
Conversion Efficiency ◽  
Plasma Electron ◽  
Quantum Plasma ◽  
Fundamental Wave ◽  
Quantum Hydrodynamic Model ◽  
Bohm Potential ◽  
Classical Plasma ◽  
Quantum Hydrodynamic ◽  
Statistical Pressure

AbstractStudy of even harmonic generation resulting from propagation of whistler pulse in homogeneous high-density quantum plasma immersed in an externally applied magnetic field, using the recently developed quantum hydrodynamic model is presented. The effects of quantum Bohm potential, quantum statistical pressure, and electron spin have been taken into account. The field amplitude of even harmonic of the whistler with respect to fundamental wave and the conversion efficiency for phase-mismatch has been analyzed. The conversion efficiency of harmonic radiation depends on the plasma electron density, magnetic field strength as well as the intensity of whistler pulse. The efficiency increases significantly with an increase in plasma density, magnetic field and whistler wave intensity. Higher conversion efficiency is observed in degenerate plasma for lower values of the static magnetic field as compared with classical plasma.

scholarly journals Ion solitary waves in a dense quantum plasma

2008 ◽  
Vol 74 (5) ◽  
pp. 581-584 ◽  
Author(s):  
B. ELIASSON ◽  
P. K. SHUKLA
Keyword(s):  
Solitary Waves ◽  
Electron Tunneling ◽  
Momentum Equation ◽  
Stationary Solutions ◽  
Quantum Plasma ◽  
Ion Density ◽  
Bohm Potential ◽  
The Poisson Equation ◽  
Ion Waves ◽  
Quantum Force

AbstractThe existence of localized ion waves in a dense quantum plasma is established. Specifically, ion solitary waves are stationary solutions of the equations composed of the nonlinear ion continuity and ion momentum equations, together with the Poisson equation and the inertialess electron momentum equation in which the electric force is balanced by the quantum force associated with the Bohm potential that causes electron tunneling at nanoscales. The solitary ion waves are characterized by a large-amplitude electrostatic potential and ion density maxima and smaller amplitude minima on the flanks of the solitary waves. We identify the speed interval for the existence of the ion solitary waves around a quantum Mach number that is of the order of unity.

scholarly journals Dispersion properties of electrostatic oscillations in quantum plasmas

2009 ◽  
Vol 76 (1) ◽  
pp. 7-17 ◽  
Author(s):  
BENGT ELIASSON ◽  
PADMA KANT SHUKLA
Keyword(s):  
Low Frequency ◽  
Electron Plasma ◽  
Quantum Plasma ◽  
Plasma Oscillations ◽  
Heisenberg Uncertainty Principle ◽  
Electrostatic Wave ◽  
Dense Plasmas ◽  
Astrophysical Objects ◽  
Heisenberg Uncertainty ◽  
Semiconductor Plasmas

AbstractWe present a derivation of the dispersion relation for electrostatic oscillations in a zero-temperature quantum plasma, in which degenerate electrons are governed by the Wigner equation, while non-degenerate ions follow the classical fluid equations. The Poisson equation determines the electrostatic wave potential. We consider parameters ranging from semiconductor plasmas to metallic plasmas and electron densities of compressed matter such as in laser compression schemes and dense astrophysical objects. Owing to the wave diffraction caused by overlapping electron wave function because of the Heisenberg uncertainty principle in dense plasmas, we have the possibility of Landau damping of the high-frequency electron plasma oscillations at large enough wavenumbers. The exact dispersion relations for the electron plasma oscillations are solved numerically and compared with the ones obtained by using approximate formulas for the electron susceptibility in the high- and low-frequency cases.

scholarly journals Identification of Linear and Nonlinear Causal Relationship Among Low-Frequency Climatic Phenomena in the Last Millennium

2019 ◽  
Author(s):  
Lucas Massaroppe ◽  
Maria Gabriela Louzada Malfatti ◽  
Igor Stivanelli Custodio ◽  
Pedro Leite da Silva Dias
Keyword(s):  
Causal Relationship ◽  
Low Frequency ◽  
Last Millennium ◽  
Linear And Nonlinear

Linear and Nonlinear Problems of Wave Resistance to the Movement of Objects Along Elastic Guides

2020 ◽  
pp. 97-121
Author(s):  
Vladimir I. Erofeev ◽  
Sergey I. Gerasimov ◽  
Elena E. Lisenkova ◽  
Alexey O. Malkhanov ◽  
Vladimir M. Sandalov
Keyword(s):  
Nonlinear Problems ◽  
Wave Resistance ◽  
Linear And Nonlinear

Error estimation for linear and nonlinear problems

2017 ◽  
pp. 183-194 ◽  
Author(s):  
Antonio Huerta ◽  
Pedro Díez ◽  
Juan José Egozcue
Keyword(s):  
Error Estimation ◽  
Nonlinear Problems ◽  
Linear And Nonlinear

Nonlinear problems of structural mechanics. Methods of optimal design of structures

2021 ◽  
Author(s):  
Boris Tuhfatullin
Keyword(s):  
Optimal Design ◽  
Steel Frames ◽  
Nonlinear Problems ◽  
Structural Mechanics ◽  
Linear And Nonlinear Programming ◽  
Several Variables ◽  
Construction Mechanics ◽  
Flat Steel ◽  
Linear And Nonlinear ◽  
Modern Technologies

The textbook discusses methods of optimal design of structures, including methods for minimizing the functions of one and several variables; methods for solving linear and nonlinear programming problems; examples of optimal design of flat steel frames with elements made of rolled and composite I-beams. It is intended for students studying in the specialty 08.05.01 "Construction of unique buildings and structures", undergraduates studying in the training program 08.04.01.24 "Modern technologies of design and construction of buildings and structures", studying the discipline "Nonlinear problems of structural mechanics", as well as for postgraduates of the direction 08.06.01 " Engineering and construction technologies. Construction of buildings and structures", studying the discipline "Construction Mechanics".

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