Electromagnetic cyclotron instabilities in bi-Kappa distributed plasmas: A quasilinear approach

Abstract

Anisotropic bi-Kappa distributed plasmas, as encountered in the solar wind and planetary magnetospheres, are susceptible to a variety of kinetic instabilities including the cyclotron instabilities driven by an excess of perpendicular temperature T⊥>T∥ (where ∥,⊥ denote directions relative to the mean magnetic field). These instabilities have been extensively investigated in the past, mainly limiting to a linear stability analysis. About their quasilinear (weakly nonlinear) development, some insights have been revealed by numerical simulations using PIC and Vlasov solvers. This paper presents a self-consistent analytical approach, which provides for both the electron and proton cyclotron instabilities an extended picture of the quasilinear time evolution of the anisotropic temperatures as well as the wave energy densities.