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arXiv · 1902.08672

Temperature-dependent Saturation of Weibel-type Instabilities in Counter-streaming Plasmas

V. Skoutnev·A. Hakim·J. Juno·J. M. TenBarge
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Abstract

We present the first 2X2V continuum Vlasov-Maxwell simulations of interpenetrating, unmagnetized plasmas to study the competition between two-stream, Oblique, and filamentation modes in the weakly relativistic regime. We find that after nonlinear saturation of the fastest-growing two-stream and Oblique modes, the effective temperature anisotropy, which drives current filament formation via the secular Weibel instability, has a strong dependence on the internal temperature of the counter-streaming plasmas. The effective temperature anisotropy is significantly more reduced in colder than in hotter plasmas, leading to orders of magnitude lower magnetization for colder plasmas. A strong dependence of the energy conversion efficiency of Weibel-type instabilities on internal beam temperature has implications for determining their contribution to the observed magnetization of many astrophysical and laboratory plasmas.

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V. Skoutnev, A. Hakim, J. Juno, J. M. TenBarge. 2019-02-22. Temperature-dependent Saturation of Weibel-type Instabilities in Counter-streaming Plasmas. https://doi.org/10.3847/2041-8213/ab0556

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