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所属单位：航天学院

发表刊物：GEOPHYSICAL RESEARCH LETTERS

关键字：VAN ALLEN PROBES COMET GRIGG-SKJELLERUP NONLINEAR-INTERACTIONS INNER MAGNETOSPHERE CRRES OBSERVATIONS CYCLOTRON WAVES NEWBORN IONS ELECTRONS PLASMAPAUSE INSTABILITY

摘要：Hydrogen band electromagnetic ion cyclotron (EMIC) waves have received much attention recently because they are found to frequently span larger spatial areas than the other band EMIC waves. Using test particle simulations, we study the nonlinear effects of hydrogen band EMIC waves on ring current H+ ions. A dimensionless parameter R is used to characterize the competition between wave-induced and adiabatic motions. The results indicate that there are three regimes of wave-particle interactions for typical 35 keV H+ ions at L = 5: diffusive (quasi-linear) behavior when alpha(eq) <= 35 degrees (R >= 2.45), the nonlinear phase trapping when 35 degrees < alpha(eq) < 50 degrees (0.75 < R < 2.45), and both the nonlinear phase bunching and phase trapping when alpha(eq) >= 50 degrees (R <= 0.75). The phase trapping can transport H+ ions toward large pitch angle, while the phase bunching has the opposite effect. The phase-trapped H+ ions can be significantly accelerated (from 35 keV to over 500 keV) in about 4 min and thus contribute to the formation of high energy components of ring current ions. The results suggest that the effect of hydrogen band EMIC waves is not ignorable in the nonlinear acceleration and resonance scattering of ring current H+ ions.

ISSN号：0094-8276

是否译文：否

发表时间：2017-12-16

合写作者：Zhai, Hao,Gao, Zhuxiu

通讯作者：王志强