Journal article
Cyclotron Acceleration of Relativistic Electrons Through Landau Resonance With Obliquely Propagating Whistler‐Mode Chorus Emissions
Journal of geophysical research. Space physics, Vol.124(4), pp.2795-2810
04/2019
DOI: 10.1029/2018JA026374
Abstract
Efficient acceleration of relativistic electrons at Landau resonance with obliquely propagating whistler‐mode chorus emissions is confirmed by theory, simulation, and observation. The acceleration is due to the perpendicular component of the wave electric field. We first review theoretical analysis of nonlinear motion of resonant electrons interacting with obliquely propagating whistler‐mode chorus. We have derived formulae of inhomogeneity factors for Landau and cyclotron resonances to analyze nonlinear wave trapping of energetic electrons by an obliquely propagating chorus element. We performed test particle simulations to confirm that nonlinear wave trapping by both Landau and cyclotron resonances can take place for a wide range of energies. For an element of large amplitude chorus waves observed by the Van Allen Probes, we have performed detailed analyses of the wave form data based on theoretical framework of nonlinear trapping of resonant electrons. We compare the efficiencies of accelerations by cyclotron and Landau resonances. We find significant acceleration can take place both in Landau and cyclotron resonances. What controls the dynamics of relativistic electrons in the Landau resonance is the perpendicular field components rather than the parallel electric field of the oblique chorus wave. In evaluating the efficiency of nonlinear trapping, we have taken into account variation of the wave trapping potential structure controlled by the inhomogeneity factors.
Key Points
Oblique chorus waves can accelerate relativistic electrons effectively through Landau resonance
The acceleration is due to the perpendicular component of the wave electric field
Nonlinear trapping conditions and efficiency of electron acceleration are confirmed by spacecraft observation
Details
- Title: Subtitle
- Cyclotron Acceleration of Relativistic Electrons Through Landau Resonance With Obliquely Propagating Whistler‐Mode Chorus Emissions
- Creators
- Yoshiharu Omura - Kyoto UniversityYi‐Kai Hsieh - Kyoto UniversityJohn C. Foster - Massachusetts Institute of TechnologyPhilip J. Erickson - Massachusetts Institute of TechnologyCraig A. Kletzing - University of IowaDaniel N. Baker - Laboratory for Atmospheric and Space Physics
- Resource Type
- Journal article
- Publication Details
- Journal of geophysical research. Space physics, Vol.124(4), pp.2795-2810
- DOI
- 10.1029/2018JA026374
- ISSN
- 2169-9380
- eISSN
- 2169-9402
- Number of pages
- 16
- Grant note
- Ministry of Education, Culture, Sports, Science and Technology, Japan and JSPS (17H06140)
- Language
- English
- Date published
- 04/2019
- Academic Unit
- Physics and Astronomy
- Record Identifier
- 9984429052202771
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