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arXiv · 1504.05243

Nonlinear sub-cyclotron resonance as a formation mechanism for gaps in banded chorus

Xiangrong Fu·Zehua Guo·Chuanfei Dong·S. Peter Gary
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Abstract

An interesting characteristic of magnetospheric chorus is the presence of a frequency gap at $\omega \simeq 0.5\Omega_e$, where $\Omega_e$ is the electron cyclotron angular frequency. Recent chorus observations sometimes show additional gaps near $0.3\Omega_e$ and $0.6\Omega_e$. Here we present a novel nonlinear mechanism for the formation of these gaps using Hamiltonian theory and test-particle simulations in a homogeneous, magnetized, collisionless plasma. We find that an oblique whistler wave with frequency at a fraction of the electron cyclotron frequency can resonate with electrons, leading to effective energy exchange between the wave and particles.

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Xiangrong Fu, Zehua Guo, Chuanfei Dong, S. Peter Gary. 2015-04-20. Nonlinear sub-cyclotron resonance as a formation mechanism for gaps in banded chorus. https://arxiv.org/abs/1504.05243

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