On kinetic effects in the ionosphericF-region modified by powerful radio waves
On kinetic effects in the ionosphericF-region modified by powerful radio waves
复制标题
强无线电波改变电离层F区的动力学效应
DOI：
10.1007/bf02677563
复制
发表时间：
1999
影响因子：
0.8
通讯作者：
S. Grach
中科院分区：
文献类型：
--
作者：
S. Grach
我们认为，在电离层F-区修改了强大的无线电波的高频等离子体湍流的电子加速相关的影响。在远离多重回旋共振的泵浦波频率下，确定了由于附加电离导致的加速粒子数雪崩增长的阈值。稳态密度的加速电子被发现为上述泵频率值考虑到湍流捕获在加速层中由于散射的等离子体波和电子返回到这一层由于碰撞。当抽运波频率接近多重回旋共振时，形成了具有显著横向各向异性的快电子分布。由于与加速层外的带电粒子的碰撞，这种分布的松弛导致在分布函数的尾部出现最大横向速度。我们提出了一个产生机制的宽上移最大功能的受激电磁辐射谱，这是有关的回旋不稳定性的加速电子。不稳定性发生在双共振区，其中泵浦频率接近上混合和多回旋频率。
We consider effects related to acceleration of electrons by high-frequency plasma turbulence in the ionospheric F-region modified by powerful radio waves. The threshold of avalanche growth of the number of accelerated particles due to additional ionization is determined for pump-wave frequencies far from the multiple cyclotron resonance. The steady-state density of the accelerated electrons is found for the above pump-frequency values taking into account both turbulent trapping in the accelerating layer due to scattering of plasma waves and the return of electrons to this layer due to collisions. If the pump wave frequency is close to the multiple cyclotron resonance, fast electron distribution with significant transverse anisotropy is formed. Relaxation of this distribution due to collisions with charged particles outside the accelerating layer leads to the appearance of a maximum over transverse velocities in the tail of the distribution function. We propose a generation mechanism for the broad upshifted maximum feature in the spectrum of stimulated electromagnetic emission, which is related to the cyclotron instability of the accelerated electrons. The instability occurs in the double-resonance region in which the pump frequency is close to both the upper-hybrid and multiple-cyclotron frequency.