Gyroresonance Between Electromagnetic Ion Cyclotron Waves and Particles in a Multi-ion Plasma  

作　　者：贺慧勇 陈良旭 田天 贺艺华 李亚捷 聂六英 

机构地区：[1]School of Physics and Electronic Sciences,Changsha University of Science and Technology [2]State Key Laboratory of Space Weather [3]School of Earth and Space Sciences,Peking University

出　　处：《Plasma Science and Technology》2009年第5期539-543,共5页等离子体科学和技术（英文版）

基　　金：National Natural Science Foundation of China (Nos.40874076,40774078,40774079 and 40536029);the Special Fund for Public Welfare Industry (meteorology)GYHY200806072;the Visiting Scholar Foundation of State Key Laboratory for Space Weather,Chinese Academy of Sciences

摘　　要：The gyroresonant interaction between electromagnetic ion cyclotron （EMIC） waves and energetic particles was studied in a multi-ion （H^＋, He^＋, and O^＋） plasma. The minimum resonant energy Emin, resonant wave frequency w, and pitch angle diffusion coefficient Daa were calculated at the center location of the symmetrical ring current： r ≈3.5RE with RE the Earth＇s radius. Emin is found to decrease rapidly from 10 MeV to a few keV with the increase in ca in three bands： H^＋-band, He^＋-band and O^＋-band. Moreover, EMIC waves have substantial potential to scatter energetic （～100 keV） ions （mainly H^＋ and He^＋） into the loss cone and yield precipitation loss, suggesting that wave-particle interactions contribute to ring current decay.The gyroresonant interaction between electromagnetic ion cyclotron （EMIC） waves and energetic particles was studied in a multi-ion （H^＋, He^＋, and O^＋） plasma. The minimum resonant energy Emin, resonant wave frequency w, and pitch angle diffusion coefficient Daa were calculated at the center location of the symmetrical ring current： r ≈3.5RE with RE the Earth＇s radius. Emin is found to decrease rapidly from 10 MeV to a few keV with the increase in ca in three bands： H^＋-band, He^＋-band and O^＋-band. Moreover, EMIC waves have substantial potential to scatter energetic （～100 keV） ions （mainly H^＋ and He^＋） into the loss cone and yield precipitation loss, suggesting that wave-particle interactions contribute to ring current decay.

关 键 词：wave-particle interaction ring current decay EMIC waves multi-ion plasma 

分 类 号：O53[理学—等离子体物理]