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arXiv 1102.2842physics.plasm-ph
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相对论电子-正电子-离子等离子体中离子声孤立波的传播

Propagation of ion-acoustic solitary waves in a relativistic electron-positron-ion plasma

E. Saberian, A. Esfandyari-Kalejahi, M. Akbari-Moghanjoughi

摘要:

在相对论流体力学模型下,利用Sagdeev赝势方法研究了由冷离子和超相对论热电子、正电子组成的完全相对论等离子体中大振幅离子声孤立波(IASW)的传播.通过对赝势结构的分析,研究了等离子体流体流动速度、热能、正电子密度和正电子温度对大振幅IASW的影响。结果表明,在等离子体流体流动速度大于孤立波流动速度的区域,随着等离子体流体流动速度的增加,势阱的深度和宽度增加,孤立波的宽度变窄,振幅变大。当等离子体流体的流动速度小于孤立波的流动速度时,这种现象正好相反。另一方面,随着热能的增加,势阱的深度和宽度减小,孤子的宽度变宽,振幅变小。另外,正电子密度的增加使孤子的最大振幅增大,宽度变窄。结果表明,改变正电子温度对IASW的宽度和振幅没有明显的影响。在完全相对论性的电子-正电子-离子(EPI)等离子体中也预言了定态类孤子任意振幅波的存在。等离子体流体的流动速度、热能、正电子密度和正电子温度对这类孤子的影响与大振幅IASW相同。

英文摘要:

Propagation of large amplitude ion-acoustic solitary waves (IASWs) in a fully relativistic plasma consisting of cold ions and ultrarelativistic hot electrons and positrons is investigated using the Sagdeev's pseudopotential method in a relativistic hydrodynamics model. Effects of streaming speed of plasma fluid, thermal energy, positron density and positron temperature on large amplitude IASWs are studied by analysis of the pseudopotential structure. It is found that in regions that the streaming speed of plasma fluid is larger than that of solitary wave, by increasing the streaming speed of plasma fluid the depth and width of potential well increases and resulting in narrower solitons with larger amplitude. This behavior is opposite for the case where the streaming speed of plasma fluid is smaller than that of solitary wave. On the other hand, increase of the thermal energy results in wider solitons with smaller amplitude, because the depth and width of potential well decreases in that case. Additionally, the maximum soliton amplitude increases and the width becomes narrower as a result of increase in positron density. It is shown that varying the positron temperature does not have considerable effect on the width and amplitude of IASWs. The existence of stationary soliton-like arbitary amplitude waves is also predicted in fully relativistic electron-positron-ion (EPI) plasmas. Effects of streaming speed of plasma fluid, thermal energy, positron density and positron temperature on these kinds of solitons are the same as that for large amplitude IASWs.

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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