English

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

High Energy Astrophysical Phenomena 2019-02-26 v1 Plasma Physics

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.

Keywords

Cite

@article{arxiv.1902.08672,
  title  = {Temperature-dependent Saturation of Weibel-type Instabilities in Counter-streaming Plasmas},
  author = {V. Skoutnev and A. Hakim and J. Juno and J. M. TenBarge},
  journal= {arXiv preprint arXiv:1902.08672},
  year   = {2019}
}

Comments

Accepted for publication in ApJL. 6 pages, 5 figures