日本地球惑星科学連合2019年大会

講演情報

[E] ポスター発表

セッション記号 P (宇宙惑星科学) » P-EM 太陽地球系科学・宇宙電磁気学・宇宙環境

[P-EM13] 内部磁気圏

2019年5月29日(水) 15:30 〜 17:00 ポスター会場 (幕張メッセ国際展示場 8ホール)

コンビーナ:海老原 祐輔(京都大学生存圏研究所)、Danny Summers(Memorial University of Newfoundland)、三好 由純(名古屋大学宇宙地球環境研究所)、齊藤 慎司(名古屋大学 大学院理学研究科)

[PEM13-P21] Relativistic Acceleration of Energetic Protons by Electromagnetic Ion Cyclotron Waves in the Jovian Magnetosphere

*関根 友博1大村 善治1Danny Summers2謝 怡凱1中村 紗都子1 (1.京都大学生存圏研究所、2.ニューファンドランドメモリアル大学)

We perform test particle simulations of nonlinear interaction between energetic protons and EMIC waves. We assume a coherent EMIC waves that have a constant frequency and propagate parallel to the magnetic field. We find that protons can be trapped and accelerated by EMIC waves. We find a very efficient acceleration process of protons in which kinetic energy of protons increases while directions of parallel velocities reverses when we assume parameters in the Jovian magnetosphere. We notice that this phenomenon is very similar to the interaction process between relativistic electrons and whistler-mode waves, which is called Relativistic Turning Acceleration (RTA) [1]. In order to analyze the phenomena, we have developed nonlinear trapping theory of interaction between relativistic protons and EMIC waves. Next, we compare the theory and simulation results. We confirm that the results satisfy the conditions for RTA. Following the trajectories of many resonant protons, we obtain time evolution of the distribution function of relativistic protons as a function of energy and equatorial pitch angle based on the numerical Green’s function method [2].



References:

[1] Y. Omura, N. Furuya, D. Summers, Relativistic turning acceleration of resonant electrons by coherent whistler-mode waves in a dipole magnetic field, Journal Geophysical Research, Vol. 112, A06236, doi:10.1029/2006JA012243, 2007.

[2] Y. Omura, Y. Miyashita, M. Yoshikawa, D. Summers, M. Hikishima, Y. Ebihara, and Y. Kubota (2015), Formation process of relativistic electron flux through interaction with chorus emissions in the Earth’s inner magnetosphere, J. Geophys. Res. Space Physics, 120, 9545–9562, doi:10.1002/2015JA021563, 2015.