Coherent generation of the auroral kilometric radiation by nonlinear beatings between electrostatic waves
Coherent generation of the auroral kilometric radiation by nonlinear beatings between electrostatic waves
复制标题
通过静电波之间的非线性跳动相干产生极光千米辐射
DOI：
10.1029/ja084ia09p05189
复制
发表时间：
1979
影响因子：
--
通讯作者：
R. Pellat
中科院分区：
文献类型：
--
作者：
A. Roux;R. Pellat
在分析中，这些波在不均匀的等离子体上进行了静电和磁化等离子体的传播。要与地磁磁场对齐。上部的杂种频率。通过相干的非线性三波过程产生到强烈的电磁辐射。统一表明，应在非凡模式下在2ΩUH处观察到最激烈的辐射。
The propagation of electrostatic plasma waves in an inhomogeneous and magnetized plasma is studied analytically. These waves, which are driven unstable by auroral beams of electrons, are shown to suffer a further geometrical amplification while they propagate toward cut-off. Simultaneously their group velocities tend to be aligned with the geomagnetic field. Then it is shown that the electrostatic energy tends to accumulate at or near ωLH and ωUH, the local lower and upper hybrid frequencies. Due to this process, large amplitude electrostatic waves with very narrow spectra should be observed near these frequencies at any place along the auroral field lines where intense beam driven instability takes place. These intense quasi-monochromatic electrostatic waves are then shown to give rise by a coherent nonlinear three wave process to an intense electromagnetic radiation. Provided that the ratio ωpe/ωce tends to be smaller than unity, it is shown that the most intense radiation should be observed at 2ωUH in the extraordinary mode.