日本地球惑星科学連合2022年大会

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[J] 口頭発表

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-EM16] 宇宙プラズマ理論・シミュレーション

2022年5月22日(日) 09:00 〜 10:30 105 (幕張メッセ国際会議場)

コンビーナ:天野 孝伸(東京大学 地球惑星科学専攻)、コンビーナ:三宅 洋平(神戸大学計算科学教育センター)、梅田 隆行(名古屋大学 宇宙地球環境研究所)、コンビーナ:中村 匡(福井県立大学)、座長:天野 孝伸(東京大学 地球惑星科学専攻)、三宅 洋平(神戸大学計算科学教育センター)

10:00 〜 10:15

[PEM16-05] Computer Simulation on Antenna Impedance of Electric Field Sensors in Magnetized Plasmas.

*深澤 伊吹1三宅 洋平2臼井 英之2草地 恒史郎2栗田 怜1小嶋 浩嗣1 (1.京都大学生存圏研究所、2.神戸大学大学院システム情報研究科)


キーワード:アンテナインピーダンス、PIC シミュレーション、プラズマ分散関係

Accurate measurement and quantitative understanding of the Earth’s magnetosphere are essential for future space utilization and development. One of the major sensors used for observing plasma waves is electric field sensors. Since the early history of plasma wave measurements in space, the dipole sensor has been commonly used on scientific spacecraft. To obtain both intensities and phases of electric fields, it is necessary to calibrate the data observed by the sensor consulting the sensor characteristics. However, the electric field sensors in plasmas show complicated properties, because plasma is a dispersive media.
In this research, we simulated the antenna impedances of electric field sensors in magnetized plasmas. We conducted full Particle-In-Cell (PIC) simulations with electric field sensors as inner boundaries. The results were evaluated considering the linear dispersion relations in magnetized plasmas.
According to the calculation results, we find that, as the plasma density and cyclotron frequency change, the frequency dependence of the antenna impedance changes significantly. Comparing the real part of the antenna impedance with the ω − k diagram obtained from the linear dispersion solver, the impedance peaks are located at the frequency where branches of plasma waves are presented at k = khalf, which corresponding to half the wavelength equal to the tip-to-tip sensor length, i.e., the sensor can be assumed as the half-wavelength dipole antenna.
In the present paper, we discuss the antenna impedance of electric field sensors in plasmas comparing the linear dispersion relations.