Turning point temperature and competition between relativistic and ponderomotive effects in self-focusing of laser beam in plasma

Journal Article · Tue Oct 15 04:00:00 EDT 2013 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.4824455· OSTI ID:22218552

Bokaei, B.; Niknam, A. R. ^[1]; Jafari Milani, M. R. ^[2]

---

1. Laser and Plasma Research Institute, Shahid Beheshti University, G.C., Tehran (Iran, Islamic Republic of)
2. Plasma Physics Research School, Tehran (Iran, Islamic Republic of)

The propagation characters of Gaussian laser beam in collisionless plasma are investigated by considering the ponderomotive and relativistic nonlinearities. The second-order differential equation of dimensionless beam width parameter is solved numerically, taking into account the effect of electron temperature. The results show that the ponderomotive force does not facilitate the relativistic self-focusing in all intensity ranges. In fact, there exists a certain intensity value that, if below this value, the ponderomotive nonlinearity can contribute to the relativistic self-focusing, or obstruct it, if above. It is also indicated that there is a temperature interval in which self-focusing can occur, while the beam diverges outside of this region. In addition, the results represent the existence of a “turning point temperature” in the mentioned interval that the self-focusing has the strongest power. The value of the turning point is dependent on laser intensity in which higher intensities result in higher turning point.

• OSTI ID: 22218552
• Journal Information: Physics of Plasmas, Journal Name: Physics of Plasmas Journal Issue: 10 Vol. 20; ISSN PHPAEN; ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
BEAM PROFILES
BEAM-PLASMA SYSTEMS
COLLISIONLESS PLASMA
DIFFERENTIAL EQUATIONS
ELECTRON TEMPERATURE
ION TEMPERATURE
LASERS
LIGHT TRANSMISSION
NONLINEAR PROBLEMS
NUMERICAL ANALYSIS
PONDEROMOTIVE FORCE
RELATIVISTIC PLASMA