摘要
本文在文［３］的基础上，考虑背景电磁波色散方程的弱磁化修正，在１＜ωｐｅ／Ωｅ＜１０的范围内（主委适用于太阳高日冕、行星际空间及星系射电喷流等），计算了由束流不稳定性直接放大正常模和反常模的增长率。增长率随着频率、ωｐｅ／Ωｅ、电磁波传播角以及非热电子入射角等参数的变化规律，和忽略磁场时的结果与文［３］大体相同，但是反常模的增长，则随着ωｐｅ／Ωｅ的增大而受到明显的抑制，因而在本文参数范围内，束流不稳定性所放大的电磁波以正常模为主，可以解释太阳ＩＩＩ型爆发和星系射电喷流的偏振性质。
On the basis of the paper[3],the weakly magnetized modification for the dispersion relation of the ambient electromagnetic waves is taken into consideration.In the range of 1<ωpe/Ωe<10 (for the solar corona,inter planetary space and galactic radio jets),the growth rates of the ordinary and extraordinary modes excited directly by beam-plasma instability are calculated. The evolution of the growth rates with the frequencies,ωpe/Ωe, the propagational angle of electromagnetic waves and the injection angle of electron beams are almost similar to the results of nonmagnetized waves. However,the growth of the extraordinary modes is evidently restricted with the increasing ωpe/Ωe, hence, in the parameters of this paper,electromagnetic waves excited by beam-plasma instability is mainly the ordinary modes,which can explain the polarization of type III solar bursts and the radio jets in active galactic nuclei.
基金
国家自然科学基金
国家攀登计划资助
