Abstract

The directivity of transverse electromagnetic waves generated in a plasma at a double plasma frequency during the coalescence of plasma waves is calculated for various angular distributions of these waves. It is shown that the directivity of the generated electromagnetic waves is determined by the angular distribution of the spectral energy density of the Langmuir waves and is practically independent of the turbulence spectrum. The case of axial symmetry of emitting area is considered. If the angular distribution of Langmuir waves is proportional to cos^δ ϑ, where ϑ is the angle between the direction of the wave vector of the Langmuir wave and the axis of the symmetry of the emitting region, the maximum of the generated transverse waves corresponds to viewing angles of α = 30°–45°, where the viewing angle is the angle between the line of sight and the axis of the emitting-area symmetry. In this case, the ratio of the maximum intensity of the generated radiation to the minimum can reach 3. If the angular distribution of turbulence is proportional to sin^δ ϑ, then the radio-emission maximum corresponds to viewing angles of α = 60°–120°. This anisotropy of the solar plasma radiation can be measured with radio observations, which will make it possible to draw a conclusion about the nature and source of Langmuir turbulence in the solar plasma.

中文翻译：

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Langmuir波的角分布对双等离子体频率下无线电发射方向性的影响

摘要

针对这些波的各种角度分布，计算了在等离子体波合并期间以双等离子体频率在等离子体中产生的横向电磁波的方向性。已经表明，所产生的电磁波的方向性由朗缪尔波的频谱能量密度的角度分布确定，并且实际上与湍流频谱无关。考虑发射区域轴向对称的情况。如果朗缪尔波的角分布正比于COS ^δϑ，其中ϑ是Langmuir波的波矢方向与发射区域对称轴之间的夹角，所产生的横向波的最大值对应于α= 30°–45°的视角，其中视角是视线与发射区域对称轴之间的角度。在这种情况下，所产生的辐射到最小的最大强度之比可以达到3.如果湍流的角分布是与sin ^δ θ，则无线电发射最大值对应于观看的α= 60°的角度- 120°。太阳等离子辐射的这种各向异性可以通过无线电观测来测量，这将有可能得出关于太阳等离子中朗缪尔湍流的性质和来源的结论。