Electron dynamics in the minimagnetosphere above a lunar magnetic anomaly

摘要: We consider a three-dimensional electromagnetic particle-in-cell simulation of the boundary layer current in mini-magnetosphere created by interaction between magnetized plasma flow, which models typical solar wind, and small-scale magnetic dipole, represents Reiner Gamma anomaly on lunar surface. The size this (measured as distance from dipole center to position where pressure local field equals dynamic wind) is one quarter that Larmor radius wind ions. In spite weak magnetization ions, formed above anomaly. mini-magnetosphere, electron dominant. Due intense electric induced charge separation, electrons entering undergo E × B drift. each hemisphere, due drift shows structure convection reverses; these structures are symmetric with respect equator. Detailed analysis cyclotron motion at edge inner obtain maximum velocity acceleration not electron's guiding center. approximately eight times upstream plasma. width becomes equal cyclotron.