Solutions of the nonlinear paraxial equation due to laser 
plasma–interactions

Osman, Frederick; Beech, Robert; Hora, Heinrich

doi:10.1017/s0263034604221139

Cited by 9 publications

(7 citation statements)

References 2 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, after the experiments of Badziak et al~1999, 2003Badziak et al~1999, , 2004aBadziak et al~1999, , 2004b! and the theory of the skin layer acceleration~Hora et Hora, 2003;Miley et al, 2003Miley et al, , 2004Osman et al, 2004aOsman et al, , 2004bHora, 2004!, the ps laser pulses in the TW to few PW range may provide the conditions A and B as explained in Section 4.…”

Section: Fusion Energymentioning

confidence: 99%

Difference between relativistic petawatt-picosecond laser-plasma interaction and subrelativistic plasma-block generation

Hora

2005

Laser Part. Beams

View full text Add to dashboard Cite

Some preliminary views are presented to the topic "Fast High Density Plasma Blocks Driven by Picosecond Terawatt Lasers" of the UWS-International Workshop 1-4 December 2004 in Sydney, Australia, underlining the motivation to explain the difference between the relativistic and the subrelativistic effects of ps-laser pulse interaction with plasma at powers above TW. This refers to specifically selected experimental and theoretical presentations at the workshop containing results for explaining the differences but also the important applications for studies on the fast ignitor scheme for application on nuclear fusion energy. One of the aims with relativistic proton beams is to realize conditions of spark ignition, while the subrelativistic case implies the generation of fast plasma blocks eventually with the possibility to ignite a fusion flame in uncompressed solid DT fuel for a power station with high efficiency.

show abstract

Section: Fusion Energymentioning

confidence: 99%

Difference between relativistic petawatt-picosecond laser-plasma interaction and subrelativistic plasma-block generation

Hora

2005

Laser Part. Beams

View full text Add to dashboard Cite

show abstract

“…There has been important work on the solution of the time-dependent nonlinear paraxial equation [Osman et al, 2000[Osman et al, , 2004, corresponding to laser plasma interaction, presenting numerical and theoretical studies in the semiclassical limit. The essential differences between the focusing and defocusing cases were investigated for an arbitrary nonlinearity.…”

Section: Introductionmentioning

confidence: 99%

Self‐focusing of an electromagnetic pulse in the ionosphere

Faisal

Bhasin

Sodha³

2009

J. Geophys. Res.

View full text Add to dashboard Cite

[1] In this paper, the self-focusing of electromagnetic pulsed beams having Gaussian and sine profiles in the ionosphere have been studied. The self-focusing of an electromagnetic pulse is caused by the nonlinearity in the dielectric function caused by the nonuniform distribution of electron temperature, determined by the Ohmic heating, solar radiation and energy loss in collisions with ions and neutrals. The radial distribution of the electron temperature causes a radial distribution of electron density and thereby that of the refractive index, which causes self-focusing. The wave frequency has been assumed to be much larger than the electron collision frequency, and the temperature of the ions has been assumed to be equal to the temperature of neutrals; this assumption is justified in the ionosphere up to a height of 400 km. In the analysis, the electromagnetic wave equation and the energy balance equation has been solved simultaneously to obtain ordinary differential equations governing the beam width parameter and the electron temperature (on and away from the axis), respectively, in the paraxial approximation. For computations, the database for the midlatitude daytime ionosphere at the height of 150 km, compiled by Gurevich (1978), has been used. The transient behavior of the electron temperature (on and away from the axis) has been graphically presented for different values of pulse widths. The dependence of the beam width parameter on the distance of propagation for different times of retardation has also been plotted and discussed.

show abstract

“…Using the formalism of Akhmanov et al [1968] and its extension by Sodha et al [1974, 1976] as well as the radial distribution of the dielectric function (as indicated in the preceding paragraph), the self‐focusing of an electromagnetic Gaussian beam in the ionosphere has been investigated in the paraxial approximation. There has been important work on the solution of the time‐dependent paraxial [ Osman et al , 2000, 2004] or nonlinear Schrödinger's equation with particular reference to solitons [ Beech and Osman , 2005]; however, this has not been made use of in the present investigation on account of the fact that the present analysis is confined to the steady state.…”

Section: Introductionmentioning

confidence: 99%

Stationary self‐focusing of Gaussian electromagnetic beams in the ionosphere

Sodha

Sharma

2006

Radio Science

View full text Add to dashboard Cite

[1] The self-focusing of a Gaussian electromagnetic beam in the ionosphere has been investigated in the paraxial approximation, when the wave frequency is much higher than the electron collision frequency and the electron cyclotron frequency; the radial redistribution of the electron/ion density on account of nonuniform Ohmic heating by the Gaussian beam is taken as the dominant self-focusing mechanism. Using the energy balance equation (considering the solar radiation) and the available database for the midlatitude daytime ionosphere, the irradiance, corresponding to different values of the electron temperature has been evaluated. A curve fit yields (at a given height) a relatively simple analytical representation of the electron temperature as a function of irradiance. This expression has been used to obtain an analytical equation for the critical curve (the relation between initial beam width versus initial axial irradiance for propagation without change in beam width). It is seen that the critical curve has two humps, which implies that there may be none, one, two, three, or four values of critical axial irradiance, corresponding to a given beam width; such a possibility has not been pointed out before. The beam width-beam power plane may be divided into three regions, corresponding to self-focusing, oscillatory divergence, and steady divergence of the beam. The dependence of the beam width parameter on the distance of propagation has been obtained for three typical points in the three regions. The numerical results correspond to horizontal propagation at a height of 150 km in the daytime midlatitude ionosphere for the wave frequency w = 5 Â 10 7 s À1 and duration less than the electron concentration relaxation time, during which the electron density remains almost unaffected by the enhanced electron temperature.Citation: Sodha, M. S., and A. Sharma (2006), Stationary self-focusing of Gaussian electromagnetic beams in the ionosphere,

show abstract

Solutions of the nonlinear paraxial equation due to laser plasma–interactions

Cited by 9 publications

References 2 publications

Difference between relativistic petawatt-picosecond laser-plasma interaction and subrelativistic plasma-block generation

Difference between relativistic petawatt-picosecond laser-plasma interaction and subrelativistic plasma-block generation

Self‐focusing of an electromagnetic pulse in the ionosphere

Stationary self‐focusing of Gaussian electromagnetic beams in the ionosphere

Contact Info

Product

Resources

About