http://arxiv.org/abs/2111.15272
Streaming cosmic rays can power the exponential growth of a seed magnetic field by exciting a non-resonant instability that feeds on their bulk kinetic energy. By generating the necessary turbulent magnetic field, the instability is thought to play a key role in the confinement and acceleration of cosmic rays at shocks. In this work we present hybrid-Particle-In-Cell simulations of the instability including Monte Carlo collisions. Simulations of poorly ionized plasmas confirm the rapid damping of the instability by proton-neutral collisions predicted by linear fluid theory calculations. In contrast we find that Coulomb collisions do not oppose the growth of the magnetic field, but under certain conditions suppress the pressure anisotropies generated by the instability and actually enhance the magnetic field amplification.
A. Marret, A. Ciardi, R. Smets, et. al.
Wed, 1 Dec 21
65/110
Comments: Under review
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