太阳物理研究组知识库

Electron and proton acceleration by a super-Dreicer electric field is investigated in a reconnecting current sheet in the presence of a guide field. The electric field is assumed to vary in space. Electrons and protons are accelerated from initial positions randomly distributed over the whole acceleration region. The stability of the energy spectrum is investigated using different numbers of test particles. The energy spectrum eventually obtained is consistent with a power-law spectrum. The spectral index of electrons increases rapidly with increasing guide field, but the index for the protons does not vary significantly. The relation of the final energy to the initial position is also studied. The results indicate that the addition of a guide field not only allows the reconnecting electric field to selectively accelerate electrons and protons from different initial positions, but also increases the number of accelerated electrons and reduces the number of protons. The final position and the pitch angles of the accelerated particles are also investigated. Finally, we also calculate the energy spectrum of particles initially distributed at the boundary of the reconnection inflow.