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Title: Ponderomotive self-focusing of Gaussian laser beam in warm collisional plasma

The propagation characteristics of a Gaussian laser beam through warm collisional plasma are investigated by considering the ponderomotive force nonlinearity and the complex eikonal function. By introducing the dielectric permittivity of warm unmagnetized plasma and using the WKB and paraxial ray approximations, the coupled differential equations defining the variations of laser beam parameters are obtained and solved numerically. Effects of laser and plasma parameters such as the collision frequency, the initial laser intensity and its spot size on the beam width parameter and the axis laser intensity distribution are analyzed. It is shown that, self-focusing of the laser beam takes place faster by increasing the collision frequency and initial laser spot size and then after some distance propagation the laser beam abruptly loses its initial diameter and vastly diverges. Furthermore, the modified electron density distribution is obtained and the collision frequency effect on this distribution is studied.
Authors:
 [1] ;  [2] ;  [3] ;  [1]
  1. Plasma Physics Research School, Tehran (Iran, Islamic Republic of)
  2. (Iran, Islamic Republic of)
  3. Laser and Plasma Research Institute, Shahid Beheshti University, G.C., Tehran (Iran, Islamic Republic of)
Publication Date:
OSTI Identifier:
22299978
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physics of Plasmas; Journal Volume: 21; Journal Issue: 6; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; BEAMS; COLLISIONAL PLASMA; COLLISIONS; DIFFERENTIAL EQUATIONS; EIKONAL APPROXIMATION; LASERS; NONLINEAR PROBLEMS; PERMITTIVITY; PONDEROMOTIVE FORCE