Whistler Chorus Amplification in the Magnetosphere: The Nonlinear Free-Electron Laser Model and the Ginzburg-Landau Equation

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Bonham, Brandon, Bhattacharjee, Amitava
Format: Preprint
Published: 2025
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866912673249099776
author Bonham, Brandon
Bhattacharjee, Amitava
author_facet Bonham, Brandon
Bhattacharjee, Amitava
contents We present a novel nonlinear model for whistler-mode chorus amplification based on the free-electron laser (FEL) mechanism. First, we derive the nonlinear collective variable equations for the whistler-electron interaction. Consistent with in situ satellite observations, these equations predict that a small seed wave can undergo exponential growth, reaching a peak of a few hundred picoteslas after a few milliseconds, followed by millisecond timescale amplitude modulations. Next, we show that when one accounts for multiple wave frequencies and wave spatial variations, the amplitude and phase of the whistler wave can be described by the Ginzburg-Landau equation (GLE), providing a framework for the investigation of solitary wave behavior of chorus modes. These findings enhance our understanding of wave-particle interactions and space weather in the Van Allen radiation belts, deepen the connection between whistler-electron dynamics and FELs, and reveal a novel connection between whistler-mode chorus and the GLE.
format Preprint
id arxiv_https___arxiv_org_abs_2506_06167
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Whistler Chorus Amplification in the Magnetosphere: The Nonlinear Free-Electron Laser Model and the Ginzburg-Landau Equation
Bonham, Brandon
Bhattacharjee, Amitava
Space Physics
We present a novel nonlinear model for whistler-mode chorus amplification based on the free-electron laser (FEL) mechanism. First, we derive the nonlinear collective variable equations for the whistler-electron interaction. Consistent with in situ satellite observations, these equations predict that a small seed wave can undergo exponential growth, reaching a peak of a few hundred picoteslas after a few milliseconds, followed by millisecond timescale amplitude modulations. Next, we show that when one accounts for multiple wave frequencies and wave spatial variations, the amplitude and phase of the whistler wave can be described by the Ginzburg-Landau equation (GLE), providing a framework for the investigation of solitary wave behavior of chorus modes. These findings enhance our understanding of wave-particle interactions and space weather in the Van Allen radiation belts, deepen the connection between whistler-electron dynamics and FELs, and reveal a novel connection between whistler-mode chorus and the GLE.
title Whistler Chorus Amplification in the Magnetosphere: The Nonlinear Free-Electron Laser Model and the Ginzburg-Landau Equation
topic Space Physics
url https://arxiv.org/abs/2506.06167