Japan Geoscience Union Meeting 2023

Presentation information

[J] Online Poster

P (Space and Planetary Sciences ) » P-EM Solar-Terrestrial Sciences, Space Electromagnetism & Space Environment

[P-EM17] Space Plasma Physics: Theory and Simulation

Tue. May 23, 2023 9:00 AM - 10:30 AM Online Poster Zoom Room (2) (Online Poster)

convener:Takanobu Amano(Department of Earth and Planetary Science, University of Tokyo), Yohei Miyake(Graduate School of System Informatics, Kobe University), Takayuki Umeda(Institute for Space-Earth Environmental Research, Nagoya University), Tadas Nakamura(Fukui Prefectural University)

On-site poster schedule(2023/5/22 17:15-18:45)

9:00 AM - 10:30 AM

[PEM17-P12] Formation of double layer in two-dimensional current carrying plasma

*Takayuki Umeda1, Ryouta Ikeba1 (1.Institute for Space-Earth Environmental Research, Nagoya University)

Keywords:double Layer, plasma, particle-in-cell simulation

Localized unipolar electric fields, which is known as electric double layers have been observed in upward and downward regions of the auroral zone [Mozer et al., 1977; Ergun et al., 2001]. However, recent in-situ observations have shown that electric double layers are not limited to the auroral acceleration region but exist in various regions of the Earth’s magnetosphere as well [Mozer et al., 2013; Imajo et al., 2021]. The previous one-dimensional Vlasov simulation study has demonstrated the formation of a double layer in a current-carrying plasma with a strong density depression [Newman et al., 2001]. However, multi-dimensional kinetic simulations on the formation of a double layer in a current-carrying plasma have not been performed over twenty years due to both computational resources and computational techniques. In the present study, the current-carrying plasma model by Newman et al. [2001] is first extended to two dimensions, by means of a state-of-art particle-in-cell simulation. The present two-dimensional particle-in-cell simulations have confirmed formation of a double layer in a two-dimensional current-carrying plasma with a density depression for ωcepe=0.1-1.0. However, the lifetime of the double layer becomes shorter with a larger ambient magnetic field. Inside a cavity region of the double layer, electrostatic and electromagnetic waves propagating in the direction quasi-perpendicular to the ambient magnetic field are enhanced stronger with a larger ambient magnetic field, which collapse the double layer. The numerical frequency-wavenumber spectrum indicates the excitation of ion acoustic and ion cyclotron harmonic waves.