Kiel 2004 – wissenschaftliches Programm
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EP: Extraterrestrische Physik
EP 9: Poster-2
EP 9.13: Poster
Dienstag, 9. März 2004, 17:45–19:30, Foyer
Quasi-Perpendicular Shocks: Full Particle Simulation with Realistic Ion to Electron Mass Ratio — •Manfred Scholer and Shuichi Matsukiyo — Max-Planck-Inst. f. extraterrestrische Physik, 85741 Garching
We demonstrate that depending on the ion to electron mass ratio assumded in full particle simulations of quasi-perpendicular shocks different physics concerning ion and electron heating will result. One-dimensional full particles electromagnetic simulations of a quasi-perpendicular shock with the same Alfén Mach number MA, shock normal - magnetic field angle Θ Bn and ion and electron beta (particle to magnetic field pressure), but with different ion to electron mass ratios will be presented. The shock is nondispersive, i.e., MA (∼ 4.5) and Θ Bn (87∘) are such that no disperisve upstream whistler waves exist, and low ion and electron beta (0.05) is investigated. At this low ion beta the shock periodically reforms itself. However, whereas at unrealistically low mass ratios the reformation is due to accumulation of specularly reflected particles at the upstream edge of the foot, at the realistic mass ratio the modified two-stream instability between the incoming solar wind ions and solar wind electrons leads to ion phase mixing and thermalization. This results eventually in shock reformation on the time scale of the inverse ion gyrofrequency. At the lowest mass ratio (80) the Buneman instability occurs between solar wind electrons and reflected ions, which is stabilized at higher mass ratios.