Unperturbed state and solitary structures in an electron-positron plasma having dust impurity and density inhomogeneity

2014 ◽  
Vol 80 (4) ◽  
pp. 629-641 ◽  
Author(s):  
Hitendra K. Malik ◽  
Rakhee Malik
Keyword(s):  
Density Gradient ◽  
Mkdv Equation ◽  
Charged Dust ◽  
Unperturbed State ◽  
Pair Plasma ◽  
Electron Positron ◽  
Electrons And Positrons ◽  
Solitary Structures ◽  
Dust Distribution ◽  
Positively Charged

An electron–positron pair plasma having dust impurity and density non-uniformity is studied for its unperturbed state and evolution of solitary structures under the effect of either positively charged or negatively charged dust grains. Zeroth-order equations are solved to examine the unperturbed state of the plasma via unperturbed potential φ0, drift velocities of the electrons and positrons (ve0 and vp0), and plasma (positron) density gradient np0η. It is observed that the dust distribution affects the gradient np0η significantly, which increases very sharply with a small increment in the dust density gradient nd0η. With relation to the solitary structures, a modified form of Korteweg–deVries equation (mKdV equation) is realized in the said plasma, which reveals that a tailing structure is associated with the soliton (sech2 structure). This tail is less prominent in the present pair plasma, contrary to the observation made in ordinary plasmas having only ions and electrons. The dust impurity is found to influence the solitary structure much significantly and its presence suppresses the rarefactive solitons, which are generally observed in multi-component species plasmas.

Soliton propagation in a moving electron-positron pair plasma having negatively charged dust grains

2012 ◽  
Vol 19 (3) ◽  
pp. 032107 ◽  
Author(s):  
Rakhee Malik ◽  
Hitendra K. Malik ◽  
Subhash C. Kaushik
Keyword(s):  
Charged Dust ◽  
Dust Grains ◽  
Soliton Propagation ◽  
Pair Plasma ◽  
Electron Positron ◽  
Electron Positron Pair

scholarly journals Beam instabilities in a magnetized pair plasma

1999 ◽  
Vol 62 (1) ◽  
pp. 65-86 ◽  
Author(s):  
MAXIM LYUTIKOV
Keyword(s):  
Growth Rates ◽  
Particle Interaction ◽  
Kinetic Regime ◽  
Pulsar Magnetosphere ◽  
Pair Plasma ◽  
Electron Positron ◽  
Pulsar Radiation ◽  
Radiation Generation ◽  
Field Lines ◽  
Beam Instabilities

Beam instabilities in the strongly magnetized electron–positron plasma of a pulsar magnetosphere are considered. We analyse the resonance conditions and estimate the growth rates of the Cherenkov and cyclotron instabilities of the ordinary (O), extraordinary (X) and Alfvén modes in two limiting regimes: kinetic and hydrodynamic. The importance of the different instabilities as a source of coherent pulsar radiation generation is then estimated, taking into account the angular dependence of the growth rates and the limitations on the length of the coherent wave–particle interaction imposed by the curvature of the magnetic field lines. We conclude that in the pulsar magnetosphere, Cherenkov-type instabilities occur in the hydrodynamic regime, while cyclotron-type instabilities occur in the kinetic regime. We argue that electromagnetic cyclotron-type instabilities on the X, O and probably Alfvén waves are more likely to develop in the pulsar magnetosphere.

Comment on ‘Propagation of solitary waves and shock wavelength in the pair plasma (J. Plasma Phys. 78, 525–529, 2012)’

2014 ◽  
Vol 80 (3) ◽  
pp. 513-516
Author(s):  
Frank Verheest
Keyword(s):  
Shock Wave ◽  
Solitary Wave ◽  
Solitary Waves ◽  
Plasma Phys ◽  
Theoretical Underpinning ◽  
Pair Plasma ◽  
Electrons And Positrons ◽  
Small Dissipation ◽  
Pseudopotential Approach ◽  
Wave Properties

In a recent paper ‘Propagation of solitary waves and shock wavelength in the pair plasma (J. Plasma Phys. 78, 525–529, 2012)’, Malekolkalami and Mohammadi investigate nonlinear electrostatic solitary waves in a plasma comprising adiabatic electrons and positrons, and a stationary ion background. The paper contains two parts: First, the solitary wave properties are discussed through a pseudopotential approach, and then the influence of a small dissipation is intuitively sketched without theoretical underpinning. Small dissipation is claimed to lead to a shock wave whose wavelength is determined by linear oscillator analysis. Unfortunately, there are errors and inconsistencies in both the parts, and their combination is incoherent.

Lofted charged dust distribution above the Moon surface

2011 ◽  
Vol 59 (14) ◽  
pp. 1795-1803 ◽  
Author(s):  
Vladimir Pines ◽  
Marianna Zlatkowski ◽  
Arnon Chait
Keyword(s):  
Charged Dust ◽  
The Moon ◽  
Dust Distribution

Inward and outward dust acoustic cylindrical and spherical waves interaction in four-component dusty plasma with nonthermal ions

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Uday Narayan Ghosh ◽  
Prasanta Chatterjee ◽  
Barjinder Kaur
Keyword(s):  
Dusty Plasma ◽  
Charged Dust ◽  
Dust Grains ◽  
Mass Ratio ◽  
Temperature Ratio ◽  
Spherical Waves ◽  
Dust Acoustic ◽  
Waves Interaction ◽  
Positively Charged ◽  
Different Time Scales

Abstract A theoretical investigation by an all-inclusive adaptation of the PLK strategy is carried out in order to study the inward and outward interaction between two cylindrical and spherical dust acoustic solitary waves (DASWs) in an unmagnetized dusty plasma consisting of nonthermal distributed ions, negatively and positively charged dust grains along with electrons featuring Boltzmann’s distribution. The interactions and collisions between two cylindrical and spherical geometries at different time scales are studied. Also the combined effects of the nonthermality of ions, ion to electron temperature ratio as well as mass ratio of positive to negative dust grains have been studied in detail on the phase shifts raised due to collision. It has been seen that the properties of the cooperation of DASWs in cylindrical and spherical shaped are distinct.

scholarly journals Progress Towards a Laser Produced Relativistic Electron-Positron Pair Plasma

2016 ◽  
Vol 688 ◽  
pp. 012010 ◽  
Author(s):  
Hui Chen ◽  
J. Bonlie ◽  
R. Cauble ◽  
F. Fiuza ◽  
W. Goldstein ◽  
...  
Keyword(s):  
Relativistic Electron ◽  
Pair Plasma ◽  
Electron Positron ◽  
Electron Positron Pair

scholarly journals Driving positron beam acceleration with coherent transition radiation

2020 ◽  
Vol 3 (1) ◽  
Author(s):  
Zhangli Xu ◽  
Longqing Yi ◽  
Baifei Shen ◽  
Jiancai Xu ◽  
Liangliang Ji ◽  
...  
Keyword(s):  
Longitudinal Magnetic Field ◽  
Transition Radiation ◽  
Positron Beam ◽  
Acceleration Process ◽  
Wakefield Acceleration ◽  
Electron Positron ◽  
Electrons And Positrons ◽  
Energy Peak ◽  
Coherent Transition Radiation ◽  
Plasma Wakefield

Abstract Positron acceleration in plasma wakefield faces significant challenges, as the positron beam must be pre-generated and precisely coupled into the wakefield and, most critically, suffers from defocusing issues. Here we propose a scheme that utilizes laser-driven electrons to produce, inject, and accelerate positrons in a single setup. The high-charge electron beam from wakefield acceleration creates copious electron–positron pairs via the Bethe–Heitler process, followed by enormous coherent transition radiation due to the electrons’ exiting from the metallic foil. Simulation results show that the coherent transition radiation field reaches up to tens of GV m−1, which captures and accelerates the positrons to cut-off energy of 1.5 GeV with energy peak of 500 MeV (energy spread ~ 24.3%). An external longitudinal magnetic field of 30 T is also applied to guide the electrons and positrons during the acceleration process. This proposed method offers a promising way to obtain GeV fast positron sources.

scholarly journals Modes of Energy Loss from Isolated Magnetized Neutron Star

1987 ◽  
Vol 125 ◽  
pp. 450-450
Author(s):  
S. Shibata
Keyword(s):  
Magnetic Field ◽  
Neutron Star ◽  
Gamma Ray ◽  
Rotational Energy ◽  
Pair Creation ◽  
Dipole Radiation ◽  
Pair Plasma ◽  
Electron Positron ◽  
Closed Current ◽  
Electron Positron Pair

Pulsar may be regarded as a discharge tube by electron-positron pair creation. On this viewpoint we carry out two numerical calculations. The obtained magnetic field is consistent with the flow. We find that pulsars emit their rotational energy through three modes simultaneously. The three modes are (1)relativistic acceleration and following gamma-ray emission in the closed current circuit in the magnetosphere, (2)wind of the electron-positron pair plasma, and (3)dipole radiation.

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