Japan Geoscience Union Meeting 2022

Presentation information

[J] Poster

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

[P-EM16] Space Plasma Physics: Theory and Simulation

Mon. May 30, 2022 11:00 AM - 1:00 PM Online Poster Zoom Room (5) (Ch.05)

convener:Takanobu Amano(Department of Earth and Planetary Science, University of Tokyo), convener:Yohei Miyake(Education Center on Computational Science and Engineering, Kobe University), Takayuki Umeda(Institute for Space-Earth Environmental Research, Nagoya University), convener:Tadas Nakamura(Fukui Prefectural University), Chairperson:Takanobu Amano(Department of Earth and Planetary Science, University of Tokyo)

11:00 AM - 1:00 PM

[PEM16-P03] Shock Drift Acceleration and Betatron Acceleration of Electrons at Nonstationary Quasi-Perpendicular Shocks

*Fumiko Otsuka1, Shuichi Matsukiyo1, Mitsuo Oka2 (1.Earth System Science and Technology, 2.UC Berkeley)

Electrons are accelerated to very high, non-thermal energies at Earth's quasi-perpendicular bow shock. Shock drift acceleration (SDA) is one of the most plausible model to produce non-thermal electrons at quasi-perpendicular collisionless shocks. In the SDA, electrons gradient-B drifting along the shock gain energy from the motional electric field. Betatron acceleration is also candidate for the energy gain at a nonstationary shock, where an overshoot magnetic field is compressed during the shock self-reformation process.

In this study, we quantify the contributions of the SDA and betatron effects on an electron acceleration process in a quasi-perpendicular shock, by performing PIC simulations. The shock parameters are as follows. The Alfven Mach number is 7, upstream plasma beta is 0.3, the shock angles are 70 degrees. We investigate which electric field components contribute to the electron energy gain, by analyzing the trajectories of electrons trapped in a thin magnetic trough embedded in the overshoot magnetic field. The result shows that the betatron acceleration effectively occurs at least comparable with the SDA. We also discuss the effect of a cross-shock potential on the electron acceleration.