A firehose-like aperiodic instability of the counter-beaming electron plasma
| Autor: | Marian Lazar, Rodrigo A. López, Shaaban Mohammed Shaaban Shaaban, Stefaan Poedts, Pablo S. Moya |
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| Rok vydání: | 2020 |
| Předmět: |
Physics
Condensed matter physics FOS: Physical sciences Electron Plasma Condensed Matter Physics Firehose instability Instability Space Physics (physics.space-ph) Physics - Plasma Physics Magnetic field Plasma Physics (physics.plasm-ph) Two-stream instability Nuclear Energy and Engineering Thermal velocity Physics - Space Physics Anisotropy |
| Popis: | Depending on the physical conditions involved the beam plasma systems may reveal new unstable regimes triggered by the wave instabilities of different nature. We show through linear theory and numerical simulations the existence of an aperiodic electromagnetic instability which solely develops and control the stability of two symmetric plasma populations counter-moving along the regular magnetic field with a relative drift, $v_d$, small enough to not exceed the particle thermal speed, $\alpha_e$. Emerging at highly oblique angles this mode resembles properties of the aperiodic firehose instability driven by temperature anisotropy. The high growth rates achieved with increasing the relative drift or/and decreasing the plasma beta parameter lead to significant saturation levels of the fluctuating magnetic field power, which explain the relative fast relaxation of electrons. For $v_d>\alpha_e$ this instability can coexist with the electrostatic two-stream instability, dominating the long-term dynamics of the plasma as soon as $v_d$ has relaxed to values smaller than the thermal speed. Comment: Submitted to: Plasma Phys. Control. Fusion on Jan. 31 2020 |
| Databáze: | OpenAIRE |
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