In 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.

中文翻译：

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自旋极化电子-正电子-离子等离子体中静电逆流不稳定性的流体力学分析

在这项研究中，我们对自旋极化电子-正电子-离子（e-p-i）等离子体中的静电逆流不稳定性进行了线性分析。借助独立的自旋演化-量子流体动力学（SSE-QHD）模型，我们推导出了逆流不稳定性的色散关系。我们用数值方法解决了色散问题，并找到了四个波解：朗缪尔波，正电子声模以及两个电子和正电子自旋相关波。注意，流和自旋效应的耦合激发了朗缪尔（Langmuir）不稳定性和正电子声模不稳定性。但是，在没有自旋效应的情况下，只有Langmuir不稳定性会在e-p-i血浆中幸存下来。我们还讨论了正电子浓度，流速度和自旋极化对波的实际频率和增长率的影响。