Observation and Numerical Modelling of Ionospheric Beat-Wave Brillouin Scattering at EISCAT
Observation and Numerical Modelling of Ionospheric Beat-Wave Brillouin Scattering at EISCAT
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EISCAT 电离层拍波布里渊散射的观测和数值模拟
DOI：
10.1109/icops37625.2020.9717650
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发表时间：
2020
期刊：
影响因子：
--
通讯作者：
Eliassen B
中科院分区：
文献类型：
--
作者：
Eliassen B
我们报道了挪威北部EISCAT的拍波驱动布里渊散射实验的新结果，在该实验中，具有普通(O)模和异常(X)模极化的大幅度无线电波被注入到头顶电离层。下降电磁波和上升电磁波在探测和泵浦的差频和波矢量与离子声波(IA)波的差频和波矢量局部匹配的高度发生共振相互作用。全波模拟证实，观测到的频率边带是由于电离层中电磁泵浦波和探测波之间的非线性混频造成的。O模和X模偏振的色散特性导致电离层中的湍流吸收过程和逃离电离层的接收信号的不同，其中O模被静电电离层湍流显著吸收，X模在到达湍流层之前被反射。这些结果对激光驱动的惯性约束聚变、磁聚变装置中的加热和电流驱动以及实验室和空间的基础等离子体物理实验具有重要意义。
We report new results of a beat-wave driven Brillouin scattering experiment at EISCAT, Northern Norway, in which large amplitude radio waves with ordinary (O) and extraordinary (X) mode polarization are injected into the overhead ionosphere. The descending and ascending electromagnetic (EM) waves interact resonantly at altitudes where the difference frequency and wave vector of the probe and pump locally match those of the ion-acoustic (IA) wave. Full-wave simulations confirm that the observed frequency sidebands are due to nonlinear wave mixing in the ionosphere between the EM pump and probe waves. The dispersive properties for O and X mode polarization lead to differences in the turbulent absorption processes in the ionosphere and in the received signals escaping the ionosphere, where the O mode is significantly absorbed by electrostatic ionospheric turbulence and the X mode is reflected before reaching the turbulent layers. The results have relevance for laser-driven inertial confinement fusion, heating and current drive in magnetic fusion devices, and for fundamental plasma physics experiments in laboratory and space.