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Title: Self-focusing and defocusing of Gaussian laser beams in collisional underdense magnetized plasmas with considering the nonlinear ohmic heating and ponderomotive force effects

Abstract

The propagation characteristics of a Gaussian laser beam in collisional magnetized plasma are investigated by considering the ponderomotive and ohmic heating nonlinearities. Here, by taking into account the effect of the external magnetic field, the second order differential equation of the dimensionless beam width parameter is solved numerically. Furthermore, the nonlinear dielectric permittivity of the mentioned plasma medium in the paraxial approximation and its dependence on the propagation characteristics of the Gaussian laser pulse is obtained, and its variation in terms of the dimensionless plasma length is analyzed at different initial normalized plasma and cyclotron frequencies. The results show that the dimensionless beam width parameter is strongly affected by the initial plasma frequency, magnetic strength, and laser pulse intensity. Furthermore, it is found that there exists a certain intensity value below which the laser pulse tends to self focus, while the beam diverges above of this value. In addition, the results confirm that, by increasing the plasma and cyclotron frequencies (plasma density and magnetic strength), the self-focusing effect can occur intensively.

Authors:
; ;  [1]
  1. Physics Department and Laser-Plasma Research Institute of Shahid Beheshti University, G.C., 19839 Evin, Tehran (Iran, Islamic Republic of)
Publication Date:
OSTI Identifier:
22486457
Resource Type:
Journal Article
Journal Name:
Physics of Plasmas
Additional Journal Information:
Journal Volume: 22; Journal Issue: 10; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 1070-664X
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; BEAM PROFILES; COLLISIONAL PLASMA; CYCLOTRON FREQUENCY; DIELECTRIC MATERIALS; DIFFERENTIAL EQUATIONS; JOULE HEATING; LANGMUIR FREQUENCY; LASER RADIATION; MAGNETIC FIELDS; NONLINEAR PROBLEMS; PERMITTIVITY; PHOTON BEAMS; PLASMA DENSITY; PONDEROMOTIVE FORCE

Citation Formats

Ettehadi Abari, Mehdi, Sedaghat, Mahsa, and Shokri, Babak. Self-focusing and defocusing of Gaussian laser beams in collisional underdense magnetized plasmas with considering the nonlinear ohmic heating and ponderomotive force effects. United States: N. p., 2015. Web. doi:10.1063/1.4933357.
Ettehadi Abari, Mehdi, Sedaghat, Mahsa, & Shokri, Babak. Self-focusing and defocusing of Gaussian laser beams in collisional underdense magnetized plasmas with considering the nonlinear ohmic heating and ponderomotive force effects. United States. https://doi.org/10.1063/1.4933357
Ettehadi Abari, Mehdi, Sedaghat, Mahsa, and Shokri, Babak. 2015. "Self-focusing and defocusing of Gaussian laser beams in collisional underdense magnetized plasmas with considering the nonlinear ohmic heating and ponderomotive force effects". United States. https://doi.org/10.1063/1.4933357.
@article{osti_22486457,
title = {Self-focusing and defocusing of Gaussian laser beams in collisional underdense magnetized plasmas with considering the nonlinear ohmic heating and ponderomotive force effects},
author = {Ettehadi Abari, Mehdi and Sedaghat, Mahsa and Shokri, Babak},
abstractNote = {The propagation characteristics of a Gaussian laser beam in collisional magnetized plasma are investigated by considering the ponderomotive and ohmic heating nonlinearities. Here, by taking into account the effect of the external magnetic field, the second order differential equation of the dimensionless beam width parameter is solved numerically. Furthermore, the nonlinear dielectric permittivity of the mentioned plasma medium in the paraxial approximation and its dependence on the propagation characteristics of the Gaussian laser pulse is obtained, and its variation in terms of the dimensionless plasma length is analyzed at different initial normalized plasma and cyclotron frequencies. The results show that the dimensionless beam width parameter is strongly affected by the initial plasma frequency, magnetic strength, and laser pulse intensity. Furthermore, it is found that there exists a certain intensity value below which the laser pulse tends to self focus, while the beam diverges above of this value. In addition, the results confirm that, by increasing the plasma and cyclotron frequencies (plasma density and magnetic strength), the self-focusing effect can occur intensively.},
doi = {10.1063/1.4933357},
url = {https://www.osti.gov/biblio/22486457}, journal = {Physics of Plasmas},
issn = {1070-664X},
number = 10,
volume = 22,
place = {United States},
year = {Thu Oct 15 00:00:00 EDT 2015},
month = {Thu Oct 15 00:00:00 EDT 2015}
}