Effect of obliquely external magnetic field on the intense laser pulse propagating in plasma medium

2020 ◽  
Vol 34 (07) ◽  
pp. 2050044
Author(s):  
Mehdi Abedi-Varaki
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Laser Pulse ◽  
Magnetoactive Plasma ◽  
Spot Size ◽  
The Self ◽  
Intense Laser ◽  
Intense Laser Pulse ◽  
Laser Spot Size ◽  
Self Focusing

In this paper, self-focusing of intense laser pulse propagating along the obliquely external magnetic field on the collisional magnetoactive plasma by using the perturbation theory have been studied. The wave equation describing the interaction of intense laser pulse with collisional magnetoactive plasma is derived. In addition, employing source-dependent expansion (SDE) method, the analysis of the laser spot-size is discussed. It is shown that with increasing of the angle in obliquely external magnetic field, the spot-size of laser pulse decreases and as a result laser pulse becomes more focused. Furthermore, it is concluded that the self-focusing quality of the laser pulse has been enhanced due to the presence of obliquely external magnetic field in the collisional magnetoactive plasma. Besides, it is seen that with increasing of [Formula: see text], the laser spot-size reduces and subsequently the self-focusing of the laser pulse in plasma enhances. Moreover, it is found that changing the collision effect in the magnetoactive plasma leads to increases of self-focusing properties.

scholarly journals Self focusing of a laser pulse in plasma with periodic density ripple

2009 ◽  
Vol 27 (2) ◽  
pp. 193-199 ◽  
Author(s):  
Sukhdeep Kaur ◽  
A.K. Sharma
Keyword(s):  
Laser Pulse ◽  
Spot Size ◽  
High Plasma ◽  
The Self ◽  
Intense Laser ◽  
Wave Number ◽  
Plasma Parameters ◽  
Density Region ◽  
Focusing Effect ◽  
Self Focusing

AbstractPropagation of an intense laser pulse in plasma with a periodically modulated density is considered using envelope equations. The laser induces modifications of the plasma refractive indexviarelativistic and ponderomotive nonlinearities. In the region of high plasma density, the self focusing effect of nonlinearity suppresses the diffraction divergence, and the laser converges. As the beam enters into the low density region, the diffraction tends to diverge it offsetting the convergence due to the curvature it has acquired. For a given set of plasma parameters, there is a critical power of the laser above which it propagates in a periodically focused manner. Below this power the laser undergoes overall divergence. At substantially higher powers, the laser beam continues to converge until the saturation effect of nonlinearity suppresses the self focusing and diffraction predominates. The effect of density ripple is to cause overall increase in the self focusing length. The minimum spot size decreases with the wave number of the ripple.

Nonlinear interaction of intense left- and right-hand polarized laser pulse with hot magnetized plasma

2017 ◽  
Vol 83 (4) ◽  
Author(s):  
M. Abedi-Varaki ◽  
S. Jafari
Keyword(s):  
Magnetic Field ◽  
Laser Pulse ◽  
Plasma Temperature ◽  
Spot Size ◽  
Magnetized Plasma ◽  
Laser Spot Size ◽  
Self Focusing ◽  
Right Hand ◽  
Left And Right ◽  
Oblique Magnetic Field

In this article, self-focusing of an intense circularly polarized laser pulse in the presence of an external oblique magnetic field in hot magnetized plasma, using Maxwell’s equations and the relativistic fluid momentum equation, is studied. An envelope equation governing the spot size of the laser beam for both of left- and right-hand polarizations has been derived and the effects of the plasma temperature and oblique magnetic field on the electron density distribution of hot plasma with respect to variation of the normalized laser spot size has been investigated. Numerical results depict that in right-hand polarization, self-focusing of the laser pulse along the propagation direction in hot magnetized plasma becomes better and more compressed with increasing $\unicode[STIX]{x1D703}$. Inversely, in left-hand polarization, increase of $\unicode[STIX]{x1D703}$ in an oblique magnetic field leads to enhancement of the spot size and reduction self-focusing. Besides, in the plasma density profile, self-focusing of the laser pulse improves in comparison with no oblique magnetic field. Also it is shown that plasma temperature has a key role in the laser spot size, normalized laser output power and the variation of plasma density.

scholarly journals Thermal behavior change in the self-focusing of an intense laser beam in magnetized electron-ion-positron plasma

2014 ◽  
Vol 32 (2) ◽  
pp. 321-330 ◽  
Author(s):  
N. Sepehri Javan ◽  
M. Hosseinpour Azad
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Laser Beam ◽  
Fluid Model ◽  
The Self ◽  
Intense Laser ◽  
Hot Electron ◽  
Circularly Polarized ◽  
Self Focusing ◽  
Electron Positron

AbstractSelf-focusing of an intense circularly-polarized laser beam in a hot electron-positron-ion magneto-plasma is studied. Using a relativistic fluid model, nonlinear equation describing laser-plasma interaction in the quasi-neutral approximation is derived. Expanding nonlinear current density in terms of normalized vector potential and saving only the parabolic terms, we investigated the self-focusing phenomenon for right- and left-hand circularly polarized laser beams. The evolution of laser beam spot size with Gaussian profile is considered. Effects of the external magnetic field, fraction of electron-positron pairs, and also the kind of polarization on the self-focusing property are studied. It is shown that a mixture of electron-positron pairs to the ion-electron plasma modifies the behavior of plasma with respect to the external magnetic field.

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