Whistler instability stimulated by the suprathermal electrons present in space plasmas

Abstract

In the absence of efficient collisions, deviations from thermal equilibrium of plasma particle distributions are controlled by the self-generated instabilities. The whistler instability is a notorious example, usually responsible for the regulation of electron temperature anisotropy $A=T_{\perp }/T_{\parallel }>$ (with $\perp ,\parallel$ respective to the magnetic field direction) observed in space plasmas, e.g., solar wind and planetary magnetospheres. Suprathermal electrons present in these environments change the plasma dispersion and stability properties, with expected consequences on the kinetic instabilities and the resulting fluctuations, which, in turn, scatter the electrons and reduce their anisotropy. In order to capture these mutual effects we use a quasilinear kinetic approach and PIC simulations, which provide a comprehensive characterization of the whistler instability under the influence of suprathermal electrons. Analysis is performed for a large variety of plasma conditions, ranging from low-beta plasmas encountered in outer corona or planetary magnetospheres to a high-beta solar wind characteristic to large heliospheric distances. Enhanced by the suprathermal electrons, whistler fluctuations stimulate the relaxation of temperature anisotropy, and this influence of suprathermals increases with plasma beta parameter.

arXiv commentaccepted for publications at Astrophysics and Space Science

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Cited by in corpus (14)

• Alternative high plasma beta regimes of electron heat-flux instabilities in the solar wind
• General dispersion properties of magnetized plasmas with drifting bi-Kappa distributions. DIS-K: DIspersion Solver for Kappa plasmas
• On quasi-parallel whistler waves in the solar wind
• Electron energy partition across interplanetary shocks: III. Analysis
• Linear Dispersion Theory of Parallel Electromagnetic Modes for Regularized Kappa-Distributions
• Electron Temperature Anisotropy and Electron Beam Constraints From Electron Kinetic Instabilities in the Solar Wind
• Towards a general quasi-linear approach for the instabilities of bi-Kappa plasmas. Whistler instability
• Whistler instabilities from the interplay of electron anisotropies in space plasmas: A quasilinear approach
• Electromagnetic ion cyclotron instability stimulated by the suprathermal ions in space plasmas: A quasi-linear approach
• A new low-beta regime for unstable proton firehose modes in bi-Kappa distributed plasmas
• Quantifying the diffusion of suprathermal electrons by whistler waves between 0.2 and 1 AU with Solar Orbiter and Parker Solar Probe
• On the interplay of solar wind proton and electron instabilities: Linear and quasi-linear approaches
• Kinetic theory of ${\mathrm{sech}}^{2}x$ electron holes and applications to Kappa-distributed plasmas
• Numerical simulations of temperature anisotropy instabilities stimulated by suprathermal protons