Linear theory of low frequency magnetosonic instabilities in counterstreaming bi-Maxwellian plasmas

Abstract

An effect of the bi-Maxwellian counterstreaming distribution function is analyzed with regard to the linear low frequency instabilities in magnetized homogeneous collisionless plasmas. New analytical marginal instability conditions for the firehose and the mirror modes have been obtained. Presence of counterstreams along the ambient magnetic field causes a huge effect on the instability conditions of those modes. The instability conditions very sensitively depend on the functional dependence of the counterstreaming parameter P. The theoretically predicted results might give a full potential explanation for the observed solar wind temperature anisotropy diagram in A-β∥ plane [S. D. Bale et al., Phys. Rev. Lett. 103, 211101 (2009)].

Kinetic instabilities in the solar wind driven by temperature anisotropies

“…Other extensions include inverse correlations using non-Maxwellian models by Xiao et al (2006Xiao et al ( , 2007, Lazar (2012); empirical inverse correlations for electrons and high-frequency instabilities by Gary et al (2005) and Š tverák et al (2008); modification of the inverse correlation by including binary collisional effects by ; efforts to rigorously calculate the inverse correlation by Isenberg (Isenberg 2012;Isenberg et al 2013) who sought to obtain a rigorous asymptotic solution of the plasma subjected to linear instability condition; including the effects of streaming population on the stability condition by Hadi et al (2014), , and Vafin et al (2015); the mutual dynamical influence of electrons and ions, considered by Michno et al (2014), Maneva et al (2016), and Shaaban et al (2016Shaaban et al ( , 2017, etc. Fig.…”

Solar wind temperature anisotropy constraints from streaming instabilities

“…Furthermore, the plasma is considered homogeneous enough and in a locally constant and homogeneous magnetic field B. Our previous work (Vafin et al 2015b) on the linear instability analysis of bi-Maxwellian counter-streaming plasmas provides that, for…”

“…However, a detailed comparison with the solar wind data has not been provided yet. The present paper provides realistic estimations for the new instability conditions (Vafin et al 2015b) (e.g., mirror, firehose) for conditions typically encountered in the solar wind, and the instability thresholds are contrasted with the observed limits of temperature anisotropy. It should be stressed that our study considers only the instability conditions and not the maximum growth rates of the instabilities.…”

Amplification of Collective Magnetic Fluctuations in Magnetized Bi-Maxwellian Plasmas for Parallel Wave Vectors. I. Electron–proton Plasma

“…However, it is wellknown that solar wind has a non-zero flow velocity or even several streams or counterstreams. It has been recently shown Vafin et al 2015aVafin et al , 2015b) that the picture of plasma instabilities in this case becomes completely different comparing to bi-Maxwellian plasma without streams. Thus, the additional presence of plasma streams in the solar wind might provide a mechanism to explain the amplification of magnetic fluctuations at A 1, but this question is beyond the scope of the present manuscript.…”