高能离子束流引起低频电磁波动的特性

CHARACTERISTICS OF LOW FREQUENCY ELECTROMAGNETICWAVES GENERATED BY HIGH ENERGY ION BEAM

理论和数值模拟研究了日冕区高速低密离子束流与等离子体相互作用产生的低频电磁波动特征 .结果表明 ,在线性阶段 ,系统波动主要表现为短波长的非共振模的激发 ;在非线性阶段 ,长波模占优 ,短波长波逐渐衰减 ,此时系统波动表现为具有Alfvn波动特征 ,波的能谱为双幂律谱 .这些结果可用来解释太阳风中的Alfvn湍动现象 .

This paper studied low frequency electromagnetic waves generated by the ion beams with high speed and low density in the coronal region by computer simulation and analytic method. Results show that in the linear phase, nonresonant mode of short wavelength is excited. In the nonlinear phase, long wavelength mode dominates, while short wavelength mode gradually decreases and waves display the features of Alfvén waves. These results can be used to explain the turbulence phenomena in the solar wind.