Opacity of an Underdense Plasma Slab due to the Parametric Instabilities of an Ultraintense Laser Pulse

Abstract

The interaction of ultraintense laser beams with underdense plasma slabs has been investigated with two-dimensional particle-in-cell numerical simulations, showing a strong absorption and a correlatively low transmission. Energetic electrons in the multi-MeV range are produced. At very high intensities the plasma transparency is recovered. These results are interpreted in terms of the development of electron parametric instabilities in the self-consistently heated plasma.

Relativistic laser-plasma interactions in the quantum regime

“…Now, we linearize our system by introducing ψ(r, t) 15), we note that the equilibrium quasi-neutrality requires that ψ 0 is normalized such that | ψ 0 | 2 = n 0 /γ A . Using that A 0 fulfills the plane wave equation (30), the linearized KGE (32), Poisson's equation (15) and the EM wave equation (17) then becomē…”

“…Thus, in a classical plasma, nonlinear effects associated with relativistic electron mass increase and relativistic ponderomotive force very important, since they provide the possibility of the modulational instability [10,11] followed by a compression and localization of intense electromagnetic waves. In addition to the modulational instability, there are relativistic Raman forward and backward scattering instabilities [12][13][14][15] and the two-plasmon decay [16] instability that lead to strong collisionless heating of the plasma in the relativistic regime. The parametric instabilities of intense electromagnetic waves in magnetized plasmas have also been investigated [17][18][19].…”

“…Equations (6), (15) and (17) are our desired system that describes intense laser-plasma interactions in the quantum regime.…”

Enhancement of vacuum polarization effects in a plasma

“…Nevertheless, the parametric instabilities saturate due to nonlinear mechanisms before the laser beam will be depleted [50]. Moreover, the transmission of the laser wave through the plasma improves at laser intensities exceeding 10 20 W/cm 2 [51], and almost half of the laser pulse can be transmitted through the plasma on the length of about 200 wavelengths. On the other hand, the profile steepening of the electron and ion densities due to the laser ponderomotive force can play a more important role.…”

Resonant Compton scattering of electromagnetic waves in a quantum plasma

“…The production of coherent gamma radiation would open up the possibilities to explore matter on sub-atomic scales. Nonlinear interactions of large-amplitude electromagnetic (EM) waves with the plasma can lead to parametric instabilities [13] and relativistic effects [14][15][16][17][18]. Collective Klein-Gordon [19] and Dirac equations [20,21] have been used to model the relativistic interactions between quantum particles and electromagnetic fields and to derive quantum fluid models for the particles.…”