Standing electromagnetic solitons in degenerate relativistic plasmas

Abstract

The existence of standing high frequency electromagnetic (EM) solitons in a fully degenerate overdense electron plasma is studied applying relativistic hydrodynamics and Maxwell equations. The stable soliton solutions are found in both relativistic and nonrelativistic degenerate plasmas.A significant amount of recent publications describe electromagnetic (EM) waves in relativistic plasmas and majority of them discuss possible roles of these waves in different astrophysical phenomena. Highly relativistic plasmas are observed in the cores of white dwarfs [2], in magnetosphere of pulsars [1], in the MeV epoch of the early Universe [4] and additionally, they probably show up in the bipolar jets in Active Galactic Nuclei (AGN) [3]. Plasma can be relativistic in two following cases: either bulk velocities of fluid cells should be close to the speed of light, or the kinetic energy of particles should be greater then their rest energy. In compact objects, such as white dwarfs and magnetars, the number densities of electrons is believed to be roughly between 10 26 cm −3 and 10 34 cm −3 [5], [6]. High density plasma can be produced in the laboratory as well, indeed contemporary petawatt laser systems have the focal intensities I = 2 × 10 22 W/cm 2 [7]. Moreover, pulses with higher than I = 10 26 W/cm 2 intensities are expected to be achieved soon [8]. Superdense plasmas might be formed with densities in the range of 10 23 cm −3 and 10 28 cm −3 [9], during the interaction of such EM pulses with solid or gaseous targets. Such plasma will be opaque for conventional laser systems operate at wavelengths λ ∼ 1µm. The Linac Coherent Light Source (LCLS) is an X-ray free-electron laser produce femtosecond powerful pulses of coherent soft and hard X-rays with wavelengths from 2.2nm to 0.06nm [10]. Exploiting the possibility to focus X-ray laser beams on a spot with down to laser wavelength, the focal intensities I ≃ 7 × 10 25 W/cm 2 are expected to be reached [11]. Successful operation of X-ray free-electron lasers in different centers world wide [12] opens up new perspectives to study the EM pulse penetration and its subsequent dynamics in super dense plasma in laboratory conditions.Highly compressed plasma with an average interparticle distance smaller than their thermal de Broglie wavelength, can be considered as a degenerate Fermi gas. When plasma density increases, the more ideal it becomes and the interactions of its particles can be neglected [13].EM solitons in classical relativistic plasma is being studied intensively [14], but existence and stability of solitary solutions in degenerate quantum relativistic plasma are investigated mostly for low frequencies (see [15] and references therein). The publication goal is to consider existence of a standing, high frequency EM soliton in the relativistic degenerate electron plasma. Importance of the standing soliton solutions for overall dynamics of EM pulses is established theoretically [16] -[19] as well as experimentally for classical relativistic plasma [20]. These publicatio...

Generation of wakefields and electromagnetic solitons in relativistic degenerate plasmas

“…Nonlinear 1D relativistic solitons were studied analytically in Refs. [25][26][27] and numerically in Refs. [28,29].…”

On the filamentation instability in degenerate relativistic plasmas

“…In a series of papers [5]- [8], where authors examined the nonlinear character of interactions of plasma waves and high frequency EM waves it was found that ✩ Fully documented templates are available in the elsarticle package on CTAN.…”

“…In the present paper, we apply the fluid-Maxwell model developed in [5], [7] to study the possibility of FI of intense narrow electromagnetic pulse L ⊥ << L (where L and L ⊥ are the characteristic longitudinal and transverse spatial dimensions of the field, respectively) in the transparent degenerate electron plasma to show the possibility of FI in relativistic degenerate plasma embedded in the field of arbitrary strong EM radiation.…”

Investigation of electromagnetic soliton in the Cairns–Tsallis model for plasma

“…For discussion on the formation and features of EM soliton, the Maxwell and fluid equations should be solved. A multiple scales technique is used to solve the fluid-Maxwell equations in cold plasma [10][11][12][13][14]. Kuehl and Zhang [15] have expressed the creation of bright and dark EM soliton in weakly relativistic approximation.…”