地球同步轨道附近哨声湍流对“种子电子”的加速

本文在等离子体准线性理论下研究了地球同步轨道附近哨声湍流对亚暴“种子电子”的波-电子共振相互作用. 当发生这种共振时，“种子电子”的动量分布函数经动量扩散而随时间演化，部分低能电子数减少了，而高能尾部分的相对论电子（能量大于1MeV）数增加了，说明“种子电子”得到了哨声湍流的有效加速，且哨声湍流的能量越高，其加速效率越高. 另外，哨声湍流的频率越低（或波数越小），共振电子的能量越高（或单位质量的动量越大）；频率范围越宽，共振电子的能量范围越宽，被加速的电子数也越多. 磁层哨声湍流加速“种子电子” 大约在30h内就可以造成相对论电子数显著增加，这正好和大多数磁暴期间观测到的相对论电子通量的增长时间相当.

ACCELERATION OF "SEED ELECTRONS" BY WHISTLER TURBULENCE NEAR THE GEOSYNCHRONOUS ORBIT

In quasi-linear approximation, we study wave-electron resonant interaction near the geosynchronous orbit. A part of lower energy electrons decrease while the higher ones increase after distribution function of electrons evolve with time via momentum diffusion, which suggest that "seed electrons" are accelerated effectively by the whistler turbulence. The larger the energy of whistler turbulence is, the higher the acceleration efficiency is. In addition, the lower the frequency of the whistler, the higher the energy of resonant electrons; and the wider the frequency range of the whistler, the wider the energy range of resonant electrons, and the more the accelerated electrons. Electron acceleration by the whistler turbulence can markedly increase the number of relativistic electrons within about 30 hours, which is consistent with the observation of relativistic electron flux enhancements during most magnetic storms.