Transverse instability of magnetized electron holes
1Space Sciences Laboratory, University of California, Berkeley, California 94720, USA.
Physical Review Letters
|September 16, 2000
Summary
Electron phase-space holes become unstable in a magnetic field due to trapped electron dynamics. A low gyro-to-bounce frequency ratio causes potential spikes to disintegrate.
Area of Science:
- Plasma physics
- Space physics
- Astrophysics
Background:
- Electron phase-space holes are nonlinear equilibria in plasmas.
- Their stability in multi-dimensional settings, especially with magnetic fields, is not fully understood.
- Previous studies have not fully addressed the role of trapped electron dynamics in their transverse stability.
Purpose of the Study:
- To investigate the transverse instability of electron phase-space holes.
- To determine the factors influencing this instability in the presence of a magnetic field.
- To clarify the long-standing problem of multi-dimensional hole stability.
Main Methods:
- Analysis of nonlinear equilibria.
- Investigating two-dimensional dynamics.
- Characterizing stability using the gyro-to-bounce frequency ratio.
Main Results:
- Identified a two-dimensional transverse instability.
- Demonstrated dependence on hole amplitudes, magnetic fields, and perpendicular velocity spread.
- Showed that a low gyro-to-bounce frequency ratio leads to disintegration of positive potential spikes.
Conclusions:
- The stability of electron phase-space holes is critically dependent on trapped electron dynamics.
- The gyro-to-bounce frequency ratio is a key parameter for understanding multi-dimensional hole stability.
- Instability leads to the disintegration of potential structures, impacting plasma dynamics.
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