Laser propagation and soliton generation in strongly magnetized plasmas

• Published in: Physics of plasmas 2016-03, Vol.23 (3)
• Main Authors: Feng, W., Li, J. Q., Kishimoto, Y.
• Format: Article
• Language: English
• Subjects: 70 PLASMA PHYSICS AND FUSION TECHNOLOGY; AMPLITUDES; APPROXIMATIONS; Circular polarization; CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; Computer simulation; EFFICIENCY; Field strength; HEAT; IONS; Laser beam heating; Laser modes; LASER-RADIATION HEATING; LASERS; MAGNETIC FIELDS; Mathematical models; One dimensional models; ONE-DIMENSIONAL CALCULATIONS; Particle in cell technique; PARTICLES; PLASMA; Plasma physics; PLASMA SIMULATION; Plasmas (physics); POLARIZATION; Propagation; Propagation modes; Pulse propagation; PULSES; Simulation; SOLITONS; TEMPERATURE DEPENDENCE; Temperature effects; Two dimensional models; TWO-DIMENSIONAL CALCULATIONS; WAVE EQUATIONS
• ISSN: 1070-664X; 1089-7674
• DOI: 10.1063/1.4942789

The propagation characteristics of various laser modes with different polarization, as well as the soliton generation in strongly magnetized plasmas are studied numerically through one-dimensional (1D) particle-in-cell (PIC) simulations and analytically by solving the laser wave equation. PIC simulations show that the laser heating efficiency substantially depends on the magnetic field strength, the propagation modes of the laser pulse and their intensities. Generally, large amplitude laser can efficiently heat the plasma with strong magnetic field. Theoretical analyses on the linear propagation of the laser pulse in both under-dense and over-dense magnetized plasmas are well confirmed by the numerical observations. Most interestingly, it is found that a standing or moving soliton with frequency lower than the laser frequency is generated in certain magnetic field strength and laser intensity range, which can greatly enhance the laser heating efficiency. The range of magnetic field strength for the right-hand circularly polarized (RCP) soliton formation with high and low frequencies is identified by solving the soliton equations including the contribution of ion's motion and the finite temperature effects under the quasi-neutral approximation. In the limit of immobile ions, the RCP soliton tends to be peaked and stronger as the magnetic field increases, while the enhanced soliton becomes broader as the temperature increases. These findings in 1D model are well validated by 2D simulations.