Hydrodynamic analysis of electrostatic counter‐streaming instability in a spin‐polarized electron–positron–ion plasma

Abstract

AbstractIn this study, we present linear analysis of electrostatic counter‐streaming instability in spin‐polarized electron–positron–ion (e‐p‐i) plasma. With the aid of the separate spin evolution‐quantum hydrodynamic (SSE‐QHD) model, we derive the dispersion relation of counter‐streaming instability. We numerically solve the dispersion and find four wave solutions: Langmuir wave, positron acoustic mode, and two electron and positron spin‐dependent waves. It is noted that coupling of streaming and spin effects excites Langmuir instability and positron acoustic mode instability. However, in the absence of spin effect, only Langmuir instability will survive in e‐p‐i plasma. We have also discussed the effects of positron concentration, streaming speed, and spin polarization on the real frequency of waves and the growth rate. The present study may be helpful for understanding longitudinal wave propagation and instabilities in dense magnetized environments.