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arXiv physics/0607237physics.plasm-phnlin.PS
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冷等离子体中的非线性磁声波

Nonlinear magnetoacoustic waves in a cold plasma

G. Rowlands, M. A. Allen

摘要:

描述在冷等离子体中的永久形式的平面磁声波的方程被重写,以突出一个自然的小参数等于电子和离子的质量比的存在。如果磁场不几乎垂直于波的传播方向,这允许我们使用多尺度展开来证明非线性波解的存在性和性质。这样的解决方案被发现有一个快速振荡的恒定振幅叠加在底层的大尺度变化。在绝热近似下,得到了大尺度变化的近似方程,在一个极限下,得到了新的显式孤立脉冲解,并在垂直磁场的情况下,得到了孤立脉冲存在的条件.我们的研究结果是一致的,与早期的研究,仅限于波具有接近的长波长线性磁声波的速度。

英文摘要:

The equations describing planar magnetoacoustic waves of permanent form in a cold plasma are rewritten so as to highlight the presence of a naturally small parameter equal to the ratio of the electron and ion masses. If the magnetic field is not nearly perpendicular to the direction of wave propagation, this allows us to use a multiple-scale expansion to demonstrate the existence and nature of nonlinear wave solutions. Such solutions are found to have a rapid oscillation of constant amplitude superimposed on the underlying large-scale variation. The approximate equations for the large-scale variation are obtained by making an adiabatic approximation and in one limit, new explicit solitary pulse solutions are found. In the case of a perpendicular magnetic field, conditions for the existence of solitary pulses are derived. Our results are consistent with earlier studies which were restricted to waves having a velocity close to that of long-wavelength linear magnetoacoustic waves.

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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