太阳大气等离子体的电流研究

The Study of the Electric Currents in Solar Atmospheric Plasma

该文讨论了太阳大气等离子体中电流的成因和对各种爆发活动的作用和影响,对目前的研究现状和存在的问题进行了分析讨论,指出虽然磁场是太阳物理观测和研究的关键要素,但是电流也是理解能量的传输与耗散、不稳定性的驱动和激发、等离子体的加热和粒子加速等太阳物理过程的重要概念.该文还提出了一个定性的改进电路模型,认为电流主要产生于太阳内部的发电机过程,同时电路在日冕部分的环形磁场位型也将产生部分新经典电流,通过磁通量管流入太阳大气,并在日冕区域通过磁场重联等过程释放能量.对该模型尚待解决的问题也进行了简单讨论.

The electric current is an important factor for the evolution of instability, energy release and transport, and particle acceleration in magnetized plasma system, such as solar atmospheric plasma. This report presents a detailed discussion on the main properties of electric currents in solar atmospheric plasma, its origin, role for plasma instabilities, and some unresolved problems. The magnetic field is a key factor for the solar observation. However, the electric current is also an important concept for understanding the processes of solar activities, such as the energy transportation and dissipation, the trigger and driver of the plasma instabilities, thc Coronal plasma heating, and particle acceleration. Such knowledge may be helpful for us to probe the evolution of other plasma systems in the universe （for example, flaring stars, active galactic nuclei, atmosphere in neutron star, etc）. In the final part of this report, the author proposes a qualitative modified electric circuit model in which the electric current is originated mainly from the dynamo process in the solar convective zone. At the same time the neoclassicai current may partially contribute to the total current and affect the evolution of the current-carrying plasma loops. These electric currents flow in the magnetic flux tubes, and release the energy by means of magnetic reconnections in solar corona. At the .end of this report some unresolved problems associated with this model are outlined.