Lepton-driven Nonresonant Streaming Instability

A strong super-Alfvenic drift of energetic particles (or cosmic rays) in a magnetized plasma can amplify the magnetic field significantly through nonresonant streaming instability (NRSI). While the traditional analysis is done for an ion current, here we use kinetic particle-in-cell simulations to study how the NRSI behaves when it is driven by electrons or by a mixture of electrons and positrons. In particular, we characterize the growth rate, spectrum, and helicity of the unstable modes, as well the level of the magnetic field at saturation. Our results are potentially relevant for several space/astrophysical environments (e.g., electron strahl in the solar wind, at oblique nonrelativistic shocks, around pulsar wind nebulae), and also in laboratory experiments.

Automated summary

This study investigates the impact of nonresonant streaming instability (NRSI) driven by electrons or a mixture of electrons and positrons in magnetized plasma on magnetic field amplification and saturation levels. The results have potential implications for various space/astrophysical environments and laboratory experiments.