Speaker
Description
Magnetic reconnection has long been known to be the most important mechanism not only for the mixing of plasmas by changing the magnetic field topology, but also for the release of magnetic field energy into plasma kinetic energy. In addition, part of the heated plasma can be accelerated to energies much higher than the thermal energy during reconnection. So far, the energy partitioning of thermal and nonthermal energy has been mainly studied using two-dimensional (2D) particle-in-cell (PIC) simulations. It has been shown that the acceleration efficiency of nonthermal particles increases with increasing plasma temperature, and the nonthermal energy density occupies more than 90% of the total heated plasma when the Alfven velocity is close to the speed of light. Here we report on the effects of three-dimensional (3D) relativistic reconnection on a pair plasma with a guide magnetic field using 3D PIC simulations. The results show that the efficiency of nonthermal particle acceleration decreases with increasing guide magnetic field for both 2D and 3D reconnection, but the decrease in nonthermal particle production is smaller for 3D guide-field reconnection compared to 2D. More importantly, because patchy and turbulent structures are generated over a large area of the plasma sheet in 3D guide-field reconnection, 3D reconnection is able to maintain a hard nonthermal energy spectrum even in the presence of a strong guide magnetic field.
