Ray tracing study of electromagnetic ion cyclotron （EMIC） waves is conducted based on a realistic plasma density model. The simulation result shows that EMIC waves propagate away from the equatorial source region to...Ray tracing study of electromagnetic ion cyclotron （EMIC） waves is conducted based on a realistic plasma density model. The simulation result shows that EMIC waves propagate away from the equatorial source region to higher latitudes basically along geomagnetic field lines, and are reflected at the region where their frequency matches the local bi-ion frequency. H＋ band suffers H＋-He＋ bi-ion frequency reflection at lower latitudes, whereas He＋ band suffers He＋-O＋ bi-ion frequency reflection at higher latitudes. Moreover, the concentration of heavy ions slightly affects the bi-ion frequencies and then slightly determines the reflection location of ray paths of EMIC waves. The current results present the first detailed study on the propagation characteristics of EMIC waves associated with bi-ion frequencies.展开更多
A theoretical investigation is carried out to study the existence,formation and basic properties of ion acoustic(IA) double layers(DLs) in a magnetized bi-ion plasma consisting of warm/cold ions and Boltzmann distribu...A theoretical investigation is carried out to study the existence,formation and basic properties of ion acoustic(IA) double layers(DLs) in a magnetized bi-ion plasma consisting of warm/cold ions and Boltzmann distributed electrons.Based on the reductive perturbation technique,an extended Korteweg de-Vries(KdV) equation is derived.The propagation of two possible modes(fast and slow),and their evolution are investigated.The effects of obhqueness,magnitude of the magnetic field,ion concentration,polarity of ions,and ion temperature on the IA DL profile are analyzed,and then the ranges of parameters for which the IA DLs exist are investigated in details.展开更多
基金supported by National Natural Science Foundation of China(Nos.40925014,41204114,and 41274165)the Aid Program for Scienceand Technology Innovative Research Team in Higher Educational Institutions of Hunan Province,Chinathe Construct Program of theKey Discipline in Hunan Province,China
文摘Ray tracing study of electromagnetic ion cyclotron （EMIC） waves is conducted based on a realistic plasma density model. The simulation result shows that EMIC waves propagate away from the equatorial source region to higher latitudes basically along geomagnetic field lines, and are reflected at the region where their frequency matches the local bi-ion frequency. H＋ band suffers H＋-He＋ bi-ion frequency reflection at lower latitudes, whereas He＋ band suffers He＋-O＋ bi-ion frequency reflection at higher latitudes. Moreover, the concentration of heavy ions slightly affects the bi-ion frequencies and then slightly determines the reflection location of ray paths of EMIC waves. The current results present the first detailed study on the propagation characteristics of EMIC waves associated with bi-ion frequencies.
文摘A theoretical investigation is carried out to study the existence,formation and basic properties of ion acoustic(IA) double layers(DLs) in a magnetized bi-ion plasma consisting of warm/cold ions and Boltzmann distributed electrons.Based on the reductive perturbation technique,an extended Korteweg de-Vries(KdV) equation is derived.The propagation of two possible modes(fast and slow),and their evolution are investigated.The effects of obhqueness,magnitude of the magnetic field,ion concentration,polarity of ions,and ion temperature on the IA DL profile are analyzed,and then the ranges of parameters for which the IA DLs exist are investigated in details.
