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

Journal Article · Sun Jun 15 04:00:00 EDT 2014 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.4883644· OSTI ID:22299978

Farahbod, A. H. ^[1]

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1. Plasma Physics Research School, Tehran (Iran, Islamic Republic of)

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.

• OSTI ID: 22299978
• Journal Information: Physics of Plasmas, Journal Name: Physics of Plasmas Journal Issue: 6 Vol. 21; ISSN PHPAEN; ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
BEAMS
COLLISIONAL PLASMA
COLLISIONS
DIFFERENTIAL EQUATIONS
EIKONAL APPROXIMATION
LASERS
NONLINEAR PROBLEMS
PERMITTIVITY
PONDEROMOTIVE FORCE