Non‐linear absorption of an intense laser pulse propagating in wiggler‐assisted underdense collisional plasma

Daraei

2023

J. Plasma Phys.

In this research, the process of electron acceleration and wakefield generation by Gaussian-like (GL), super-Gaussian (SG) and Bessel–Gaussian (BG) laser pulses through cold collisionless plasma in the presence of a planar magnetostatic wiggler are studied. Three different types of laser spatial profiles, GL, SG and BG, are considered. Additionally, using the hydrodynamics fluid equations, Maxwell's equations as well as the perturbation technique for GL, SG and BG laser pulses in the weakly nonlinear regime and in the presence of a planar magnetostatic wiggler, governing equations for analysing the laser wakefield and electron acceleration have been derived and compared correspondingly. In addition, the effect of some important factors, including the wiggler field strengths, laser intensity, pulse length, plasma electron density and laser frequency on the wakefield and the electron energy gain, have been investigated. Numerical results show that enhancing the wiggler magnetic field results in an increase in the amplitude of the wakefield. Furthermore, it is observed that in comparison with the wakefield amplitude excited by SG and GL laser pulses, the amplitude of the wakefield excited by BG laser pulse is larger when the wiggler field is enhanced. Moreover, it is realized that the type of the laser profile, selected laser parameters and wiggler magnetic field are the most decisive and effective factors in the wakefield amplitude and shape of wakefield generation through cold collisionless plasma. Also, it is seen that as the pulse length declines, the amplitude of the wakefield increases, and correspondingly the resonance positions shift to higher ${({\varOmega _w}/{\varOmega _p})_{max}}$ values.

Section: Introductionmentioning

confidence: 99%

“…One of the areas of interest for researchers is the study into the effects of external fields such as the wiggler field and the uniform magnetic fields on the interactions of intense laser pulses with plasma. These fields have a centralizing role on the electron beam that is employed to accelerate within the plasma (Abedi-Varaki 2017;Abedi-Varaki & Jafari 2017a,b, 2018aAbedi-Varaki & Panahi 2019;Gopal et al 2021a). The electron acceleration in the laser-plasma interaction leads to nonlinear effects such as self-focusing, self-modulation, filamentation, second-harmonic generation, terahertz radiation generation and so on.…”

Section: Introductionmentioning

confidence: 99%

Impact of wiggler magnetic field on wakefield generation and electron acceleration by Gaussian, super-Gaussian and Bessel–Gaussian laser pulses propagating in collisionless plasma

Daraei

2023

J. Plasma Phys.

“…[ 16–18 ] In addition, the interaction of intense laser pulse with plasma can lead to a number of nonlinear effects including, self‐focusing, [ 19–25 ] self‐compression, [ 26–28 ] Raman and Brillouin scattering instabilities, [ 29 ] as well as modulational and filamentational instabilities. [ 30–32 ] As is well known, self‐focusing is a non‐linear optical phenomenon that can occur as a result of intensity‐dependent refraction. Indeed, self‐focusing (de‐focusing) occurs while the refractive index is an increasing (decreasing) pulse intensity function.…”

Section: Introductionmentioning

confidence: 99%

Influence of non‐uniform magnetic field on relativistic q‐Gaussian laser pulses propagating in magnetized plasmas

Daraei

Contributions to Plasma Physics

2022

In this work, the influence of a non‐uniform magnetic field on the self‐focusing of relativistic q‐Gaussian (QG) laser pulse propagating in magnetized plasma is studied. Utilizing the non‐linear Schrodinger equation with higher‐order paraxial approximation, the higher‐order terms of the dielectric function and the eikonal in the presence of a non‐uniform magnetic field have been obtained. Numerical results reveal that while the non‐uniform magnetized field decreases, the pulse width parameter (g) decreases, and subsequently the spot‐size of the laser declines too. As a consequence, the QG laser pulse will be more focused. Besides, it is shown that increasing the values of q‐parameter leads to a decline in self‐focusing qualities and, at lower values of q‐parameter, sharp self‐focusing of QG laser pulse is observed. Furthermore, it is found that when the QG laser pulse is propagated in the magnetized plasma, the amplitude of the pulse width decreases with decreasing the δ‐parameter, and consequently, the laser pulse becomes more compressed. Moreover, it is observed that the application of a non‐uniform magnetic field improves the self‐focusing of the QG laser pulse propagated through magnetized plasma.

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

2020

Int. J. Mod. Phys. B

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.