The Effects of Relative Drift Velocities Between Proton and He^(2+) on the Magnetic Spectral Signatures in the Plasma Depletion Layer  

作　　者：郭俊 

机构地区：[1]College of Mathematics and Physics,Qingdao University of Science and Technology [2]State Key Laboratory of Space Weather,Chinese Academy of Sciences

出　　处：《Plasma Science and Technology》2011年第5期557-560,共4页等离子体科学和技术（英文版）

基　　金：supported by National Natural Science Foundation of China (No. 40974097);the Specialized Research Fund for State Key Laboratories, China

摘　　要：Magnetic spectrum of the electromagnetic ion cyclotron waves in the terrestrial plasma depletion layer （PDL） are sometimes observed to have a BIF （bifurcated） signature, where a diminution around 0.5Ωp with Ωp the proton gyrofrequency, occurs between two activity peaks in the spectrum. By one-dimensional hybrid simulations, the effect of relative drift velocities between protons and He2＋ on the magnetic spectral signatures in the PDL is studied. The results show that the relative drift velocity enhances the development of proton cyclotron waves and declines the development of helium cyclotron waves. The proton cyclotron waves are firstly excited, and followed by the excitation of helium cyclotron waves due to the increase in the relative drift velocity. Moreover, the boundary between two activity peaks gets obscure.Magnetic spectrum of the electromagnetic ion cyclotron waves in the terrestrial plasma depletion layer （PDL） are sometimes observed to have a BIF （bifurcated） signature, where a diminution around 0.5Ωp with Ωp the proton gyrofrequency, occurs between two activity peaks in the spectrum. By one-dimensional hybrid simulations, the effect of relative drift velocities between protons and He2＋ on the magnetic spectral signatures in the PDL is studied. The results show that the relative drift velocity enhances the development of proton cyclotron waves and declines the development of helium cyclotron waves. The proton cyclotron waves are firstly excited, and followed by the excitation of helium cyclotron waves due to the increase in the relative drift velocity. Moreover, the boundary between two activity peaks gets obscure.

关 键 词：ion cyclotron wave hybrid simulation temperature anisotropy 

分 类 号：O53[理学—等离子体物理]