Whistler-Mode Waves Growth by a Generalized Relativistic Kappa-Type Distribution
ZHOU Qing-Hua1,2, JIANG Bin1, SHI Xiang-Hua1, LI Jun-Qiu1
1School of Physics and Electronic Sciences, Changsha University of Science and Technology, Changsha 4100762State Key Laboratory of Space Weather, Chinese Academy of Sciences, Beijing 100080
Whistler-Mode Waves Growth by a Generalized Relativistic Kappa-Type Distribution
ZHOU Qing-Hua1,2, JIANG Bin1, SHI Xiang-Hua1, LI Jun-Qiu1
1School of Physics and Electronic Sciences, Changsha University of Science and Technology, Changsha 4100762State Key Laboratory of Space Weather, Chinese Academy of Sciences, Beijing 100080
摘要The instability of field-aligned Whistler-mode waves in space plasmas is studied by using a recently developed generalized relativistic kappa-type (KT) distribution. Numerical calculations are performed for a direct comparison between the new KT distribution and the current kappa distribution. We show that the wave growth for the KT distribution tends to occur in the lower wave frequency (e.g., ω≤0.1 Ωe) due to a larger fractional number of the resonant electrons ηrel (which controls the wave growth), while primarily locating in the higher wave frequency for the kappa distribution. Moreover, the relativistic anisotropy Arel by the KT distribution is found to be smaller than that by the kappa distribution, leading to a smaller peak of wave growth. The results present a further understanding of plasma wave instability particularly in those plasmas where relativistic electrons are present.
Abstract：The instability of field-aligned Whistler-mode waves in space plasmas is studied by using a recently developed generalized relativistic kappa-type (KT) distribution. Numerical calculations are performed for a direct comparison between the new KT distribution and the current kappa distribution. We show that the wave growth for the KT distribution tends to occur in the lower wave frequency (e.g., ω≤0.1 Ωe) due to a larger fractional number of the resonant electrons ηrel (which controls the wave growth), while primarily locating in the higher wave frequency for the kappa distribution. Moreover, the relativistic anisotropy Arel by the KT distribution is found to be smaller than that by the kappa distribution, leading to a smaller peak of wave growth. The results present a further understanding of plasma wave instability particularly in those plasmas where relativistic electrons are present.
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2009, Vol. 26 
