[P-EM17] 宇宙プラズマ理論・シミュレーション

[PEM17-03] Particle-In-Cell Simulations of Interferometry Observations by Single Spacecraft

*深澤 伊吹¹、三宅 洋平²、臼井 英之²、草地 恒史郎²、栗田 怜³、小嶋 浩嗣³ (1.京都大学大学院工学研究科、2.神戸大学大学院システム情報学研究科、3.京都大学生存圏研究所)

キーワード：干渉計観測、プラズマ波動、PICシミュレーション

One of the most important parameters of plasma waves is phase velocities.Interferometry observations by a single spacecraft can be used to obtain the phase velocities of plasma waves in space. Such observations use the electric field signals picked up by two monopole electric-field sensors.The phase velocity is obtained from the phase difference between the waveforms received by these sensors.However, the complexity of the electric field observations introduces uncertainty.For example, For example, the distance between observation points depends on the type of electric field sensor.Furthermore, the spacecraft body and the electric field sensors could distort the electric field wavefront. Evaluations based on realistic models of plasma environments are important for obtaining precise phase velocities from observations.
We perform three-dimensional full particle-in-cell simulations to evaluate the interferometry technique applied to Langmuir waves excited by bump-on-tail instability.The sensor elements in the simulations are simple conductive rods with a particular length. Although the whole of each sensor element picks up plasma waves, the simulation results show that the phase difference between the waveforms received by the two monopole sensors is consistent with the phase difference between two points on an element separated by a certain distance that is almost equal to the sensor's center-to-center distance.