教師資料查詢 | 類別: 會議論文 | 教師: 汪愷悌 WANG KAITI (瀏覽個人網頁)

標題:Electron Pitch-Angle Scattering by Oblique Whistler Waves: Comparison between Test Particle Simulation and Quasi-Linear Theory
學年109
學期1
發表日期2020/11/16
作品名稱Electron Pitch-Angle Scattering by Oblique Whistler Waves: Comparison between Test Particle Simulation and Quasi-Linear Theory
作品名稱(其他語言)
著者Otsuka, F.; K. Wang; T. Hada; S. Matsukiyo
作品所屬單位
出版者
會議名稱9th VERSIM Workshop (VERSIM 2020)
會議地點Online(Kyoto, Japan)
摘要Whistler-mode waves play an important role in pitch-angle scattering of electrons in the Earth's magnetosphere. THEMIS mission revealed that oblique whistler-mode waves were present at dipolarization sites near the magnetic equator in the tailside around L=10. The observed wave frequencies are in the range between the proton gyrofrequency and half the electron gyrofrequency. For these obliquely propagating electromagnetic waves, not only cyclotron resonance but also Landau resonance (or transit time damping) contributes to the electron scattering [1, 2]. When the wave amplitude is small and the spectrum is broadband, the standard
quasi-linear theory is known to work quite well to describe the pitch-angle diffusion of particles (e.g., [3]). For exactly parallel propagation cases, the validity of the quasi-linear description was examined by test particle simulations (e.g., [4, 5]). However, quasi-linear
diffusion with obliquely propagating whistler mode waves has not been discussed in detail using test particle simulations. In this presentation, we study the electron pitch-angle scattering caused by the oblique whistler waves, performing test particle simulations. We specify the oblique whistler waves obeying the cold plasma dispersion relation and assume a Gaussian wave spectrum. We integrate the motion of relativistic electrons in the given electromagnetic fields and evaluate the pitch angle diffusion coefficients for different set of parameters.
We compare the numerical diffusion coefficient with those predicted by the quasi-linear theory, and discuss the dependence on the wave propagation angle relative to the background magnetic field. The results will be applied to understanding of the electron scattering process in the dipolarization sites of the Earth's magnetosphere.
關鍵字
語言英文
收錄於
會議性質國際
校內研討會地點
研討會時間20201116~20201120
通訊作者
國別日本
公開徵稿
出版型式
出處
相關連結
Google+ 推薦功能,讓全世界都能看到您的推薦!