10:00 〜 10:15
[PEM16-05] Computer Simulation on Antenna Impedance of Electric Field Sensors in Magnetized Plasmas.
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.
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.