Xiao Fu-Liang et al 2009 Chinese Phys. Lett. 26 119401 doi:10.1088/0256-307X/26/11/119401
Xiao Fu-Liang1,2, Tian Tian3, Chen Liang-Xu1, Su Zhen-Peng4 and Zheng Hui-Nan4
Show affiliationsWe investigate the evolution of the phase space density (PSD) of ring current protons induced by electromagnetic ion cyclotron (EMIC) waves at the location L = 3.5, calculate the diffusion coefficients in pitch angle and momentum, and solve the standard two-dimensional Fokker–Planck diffusion equation. The pitch angle diffusion coefficient is found to be larger than the momentum diffusion coefficient by a factor of about 103 or above at lower pitch angles. We show that EMIC waves can produce efficient pitch angle scattering of energetic (≈ 100 keV) protons, yielding a rapid decrement in PSD, typically by a factor of ≈ 10 within a few hours, consistent with observational data. This result further supports previous findings that wave-particle interaction is responsible for the rapid ring current decay.
94.30.Lr Magnetic storms, substorms
94.20.wj Wave/particle interactions
Issue 11 (November 2009)
Received 7 April 2009
Xiao Fu-Liang et al 2009 Chinese Phys. Lett. 26 119401
X S Li 2008 J. Phys.: Conf. Ser. 125 012079
D V Vassilevich 2009 Class. Quantum Grav. 26 145010
Parthapratim Biswas et al 2007 J. Phys.: Condens. Matter 19 455202
M Krug et al 2009 New J. Phys. 11 105051
S Satake et al 2009 J. Phys.: Conf. Ser. 191 012012
Seung-Bok Choi et al 2009 Smart Mater. Struct. 18 125010
J D Alexander et al 2009 J. Phys. B: At. Mol. Opt. Phys. 42 141004
Songbai Chen and Jiliang Jing 2009 Class. Quantum Grav. 26 155006
S R Gocić et al 2009 J. Phys. D: Appl. Phys. 42 212001