In situ evidence of the modification of the parallel propagation of EMIC waves by heated He + ions
2016; Wiley; Volume: 121; Issue: 7 Linguagem: Inglês
10.1002/2016ja022573
ISSN2169-9402
AutoresZhigang Yuan, Xiongdong Yu, Dedong Wang, S. Y. Huang, Haimeng Li, Tao Yu, Zheng Qiao, J. R. Wygant, H. O. Funsten,
Tópico(s)Magnetic confinement fusion research
ResumoAbstract With observations of the Van Allen Probe B, we report in situ evidence of the modification of the parallel propagating electromagnetic ion cyclotron (EMIC) waves by heated He + ions. In the outer boundary of the plasmasphere, accompanied with the He + ion heating, the frequency bands of H + and He + for EMIC waves merged into each other, leading to the disappearance of a usual stop band between the gyrofrequency of He + ions (Ω He+ ) and the H + cutoff frequency ( ω H+co ) in the cold plasma. Moreover, the dispersion relation for EMIC waves theoretically calculated with the observed plasma parameters also demonstrates that EMIC waves can indeed parallel propagate across Ω He+ . Therefore, the paper provides an in situ evidence of the modification of the parallel propagation of EMIC waves by heated He + ions.
Referência(s)