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.

Harmonic generation in magnetized plasma for electromagnetic wave propagating parallel to external magnetic field

“…The magnetic field requirement is high (and hence not possible to achieve) for eliciting a magnetized response at laser frequencies from the charged species of the plasma. However, recent technological development in producing high magnetic fields of the order of kilo Tesla in the laboratory [33], and proposals to produce even stronger magnetic fields, in the order of Mega Tesla [34], has sparked research interest in the area of lasers interacting with magnetized plasmas, for which a variety of theoretical and simulation studies are now being conducted [35][36][37][38][39][40][41][42][43][44]. On the other hand, the available microwave and RF sources typically have low power and produce continuous waves.…”

Ion heating in laser interacting with magnetized plasma

“…This has opened up the possibility of studying the regime of laser interacting with magnetized plasmas. Recently, a number of studies have been carried out to explore this particular regime using particle-in-cell (PIC) simulations [34][35][36][37]. New mechanisms of laser energy coupling to ions have been proposed, which rely on generating electrostatic fields as a result of the difference between ⃗ E × ⃗ B 0 (Here ⃗ E is the oscillating electric field of the laser and ⃗ B 0 is the applied magnetic field) drifts and/or ponderomotive force felt by ions and electrons [38,39].…”