Utilizing the Hamiltonian Dynamics to Study Resonant Interactions of Whistler-Mode Waves and Electrons in the Solar Wind

Abstract

To study the interaction of solar wind electrons and large-amplitude whistler waves, a vectorized test particle simulation was developed with a variational component to calculate the Lyapunov exponents. A description of particle dynamics using the Hamiltonian formulation and secular perturbation theory confirmed that the electron’s pitch angle diffusion was along the constant Hamiltonian surface and that it was driven by the interaction with the resonance surfaces. Also, the role of large-amplitude whistlers in the scattering of solar wind electrons was established. Oblique whistlers were shown to be able to efficiently scatter field-aligned strahl electrons into the halo population in the solar wind. These waves could generate horn-like features in the velocity distribution function, consistent with the behavior reported in recent Particle-In-Cell studies.