Dielectric constant and laser beam propagation in an underdense collisional plasma: effects of electron temperature

Abstract

Dielectric constant and laser beam propagation in an underdense collisional plasma are investigated, using the wave and dielectric function equations, for their dependence on the electron temperature. Simulation results show that, due to the influence of the ponderomotive force there is a nonlinear variation of electron temperature in an underdense collisional plasma, and this leads to a complicated and interesting nonlinear variation of dielectric constant; this nonlinear variation of dielectric constant directly affects the beam propagation and gives rise to laser beam self-focusing in some spatial-temporal regions; in particular, the beam width and the beam intensity present an oscillatory variation in the self-focusing region. The influence of several parameters on the dielectric function and beam self-focusing is discussed.

Nonlinear structure of electromagnetic field, electron temperature and electron density in interaction of relativistic laser and plasma with density ripple

“…In the nonlinear effects, due to electromagnetic field, plasma density, and temperature have important influence on laser-plasma interaction, and their distribution and influence have been a research hotspot (Xia & Xu, 2013;Harilal et al, 1997;Xia et al, 2011a;2011b). In theoretical researched works, Qiao et al (2005) have discussed the magnetic-field profile and plasma density cavitation in intense laser-plasma interaction and found they depend on the laser intensity.…”

Collisions effect in the heating of underdense plasma by a high-intensity short laser pulse

“…The propagation of an electromagnetic pulse in collisional plasmas may involve a variety of physical phenomena [22][23][24][25]. In collisional plasma, the focusing of electromagnetic beams is due to a nonuniform profile of the dielectric function on account of nonuniform ohmic heating and of the associated electron plasma diffusion.…”

Effect of Higher Order Axial Electron Temperature on Self-Focusing of Electromagnetic Pulsed Beam in Collisional Plasma

“…[3] In these phenomenon, beam self-focusing is a very important nonlinear phenomenon, which not only affect the ratio of absorption and conversion on electromagnetic beam but also influence other parameters instabilities. In general, there are three types mechanism of beam selffocusing formation, viz., relativistic, [4] ponderomotive, [5] and collisional, [6] have been identified and many papers on the role of these nonlinearities in the self focusing of the beams have been published [7−8] in the last 40 years.…”