Nonlinear Waves and Coherent Structures in Laser Induced Plasmas and Polarized Vacuum
- PDF / 4,592,355 Bytes
- 23 Pages / 612 x 792 pts (letter) Page_size
- 2 Downloads / 214 Views
onlinear Waves and Coherent Structures in Laser Induced Plasmas and Polarized Vacuum Stephan I. Tzenov* Extreme Light Infrastructure—Nuclear Physics (ELI-NP), Magurele, Bucharest Ilfov County, 077125 Romania *e-mail: [email protected] Received February 14, 2020; revised March 13, 2020; accepted March 23, 2020
Abstract—Starting from the Vlasov–Maxwell equations describing the dynamics of various species in a free quasi-neutral plasma, an exact relativistic hydrodynamic closure for a special type of water-bag distributions satisfying the Vlasov equation has been derived.It has been shown that the set of equations for the macroscopic hydrodynamic variables coupled to the wave equations for the self-consistent electromagnetic field is equivalent to the Vlasov–Maxwell system. In the case of magnetized quasi-neutral plasma, the hydrodynamic substitution has been used to derive the hydrodynamic equations for the plasma density and current velocity, coupled to the wave equations for the self-consistent electromagnetic fields. Based on the method of multiple scales, a system comprising a vector nonlinear Schrodinger equation for the transverse envelopes of the selfconsistent plasma wakefield, coupled to a scalar nonlinear Schrodinger equation for the electron current velocity envelope for free plasma, has been derived. In the case of magnetized plasma, it has been shown that the whistler wave envelopes of the three basic modes satisfy a system of three coupled nonlinear Schrodinger equations. Numerical examples for typical plasma parameters have been presented, which demonstrate the relevance of the results thus obtained to the so-called shock laser-plasma acceleration. In addition, it has been shown that in the case of magnetized plasma, the whistler waves facilitate the transverse confinement considerably. The effect of the nonlinear corrections to the electric displacement vector and the intensity of the magnetic field in nonlinear electrodynamics of Heisenberg-Euler type has been studied. It has been shown that the slowly varying wave envelope in free polarized vacuum satisfies a nonlinear wave equation. In the case, where an external constant magnetic field is applied, the single nonlinear wave equation should be replaced by a system of two coupled nonlinear equations for the two independent wave polarizations. In both cases a novel effect of reduction of the speed of light can be observed, which is due to the vacuum polarization. DOI: 10.1134/S1063779620050081
1. INTRODUCTION The limitation of the accelerating field in modern technology superconducting radio-frequency cavities is about 100 MV/m due to electrical breakdown of the metallic surface. In order to reach higher energies, it is necessary to increase the acceleration length, and thus the size of the accelerator facility. In the mid 1950s, Budker and Veksler [1, 2] proposed utilizing plasma collective fields to accelerate charged particles more compactly. Twenty years later the idea of the wake field acceleration was further developed by Toshi Tajima and
Data Loading...
