Magnetic field generation and relativistic electron dynamics in circularly polarized intense laser interaction with dense plasma

Abstract

The generation of both axial and azimuthal magnetic field components by the intense laser-dense plasma interaction and relativistic electron dynamics are studied in theoretical analysis and three-dimensional particle-in-cell simulations. For a circularly polarized laser, the cylindrical symmetry can be applied. Interacting with this laser, both axial and the azimuthally magnetic fields are generated and play an essential role in hot electron beam collimation, stabilization, and shaping. It is significantly different from the linearly polarized case, where the azimuthal current and the axial magnetic field are absent, therefore the axial current density gets filamentary early in the ramp plasma and is focused into a single channel in the dense (with a density larger than the critical density nc) plasma later, and the electron and ion density distributions as well as the azimuthally magnetic field profile are broadened in the polarized direction to form an ellipse-like structure in the transverse plane. Instead, the results for the circularly polarized laser analytically and numerically show a much better collimation of the relativistic electron beams than in the case of the linearly polarized laser, due to the axial field component generated by azimuthal electron dynamics.