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arXiv 1608.01080physics.plasm-ph
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碰撞对有限长等离子体中双流不稳定性的影响

Effect of collisions on the two-stream instability in a finite length plasm

Dmytro Sydorenko, Igor D. Kaganovich, Peter L. G. Vetzek

摘要:

用解析和数值方法研究了单能电子束在接地壁间碰撞一维等离子体中的不稳定性。电子和中性粒子之间的碰撞只考虑等离子体电子。色散方程的解表明,不稳定性的时间增长率是碰撞频率的线性递减函数,当碰撞频率为无碰撞增长率的2倍时,不稳定性的时间增长率变为零。流体模拟证实了这一结果。实用的公式给出了估计的阈值束流,这是所需的双流不稳定性发展为一个给定的系统长度,中性气体压力,等离子体密度,和光束能量。不同的中性密度和束流进行的粒子在细胞中的模拟表现出良好的一致性与流体理论的预测的增长率和阈值束流。

英文摘要:

The instability of a monoenergetic electron beam in a collisional one-dimensional plasma bounded between grounded walls is considered both analytically and numerically. Collisions between electrons and neutrals are accounted for the plasma electrons only. Solution of a dispersion equation shows that the temporal growth rate of the instability is a decreasing linear function of the collision frequency which becomes zero when the collision frequency is two times the collisionless growth rate. This result is confirmed by fluid simulations. Practical formulas are given for the estimate of the threshold beam current which is required for the two-stream instability to develop for a given system length, neutral gas pressure, plasma density, and beam energy. Particle-in-cell simulations carried out with different neutral densities and beam currents demonstrate good agreement with the fluid theory predictions for both the growth rate and the threshold beam current.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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