Observations of Brillouin scattering process in Particle-In-Cell simulations for laser pulse interacting with magnetized overdense plasma

Abstract

Parametric processes play an important role in applications related to laser plasma interaction [P K Kaw, Review of Modern Plasma Physics, 1.1 (2017)]. Occurrence of these processes has primarily been reported in the context of laser interacting with an un-magnetized plasma. The regime of magnetized plasma, on the other hand, has remained largely unexplored from this perspective. Recent technological advancements in the production of high magnetic fields [Nakamura, Daisuke, et al, Review of Scientific Instruments, 89.9, 095106 (2018)] bring the area of laser interaction with magnetized plasma targets to the forefront of investigation. In this study, the parametric process of Brillouin scattering for a magnetised plasma target has been demonstrated with the help of one dimensional Particle-in-cell simulations using the platform of OSIRIS-4.0. The external magnetic field has been chosen to be directed along the laser propagation direction. This geometry supports the propagation of right (R) and left (L) circularly polarized electromagnetic waves in the plasma when the laser frequency falls in the appropriate pass band of the respective dispersion curves. A detailed study identifying the scattering process with differing strengths of the applied external magnetic field, and for various polarizations of the incident electromagnetic pulse has been carried out. The conditions favouring the excitation of parametric Brillouin scattering process has been outlined. The nonlinear regime of the scattering process has also been investigated.