Further investigation of energy principle for model current sheets

摘要

In the present paper we revisit the energy principle associated with magnetic reconnection. In the earlier approach the boundary of the system was freely adjusted to always contain one full period of the magnetic islands. In view of the fact that in simulations of reconnection such an adjustment of the boundary size is not feasible, in the present paper we reconsider a fixed boundary problem. It is shown that the energy conversion is almost negligible in such a situation. It is thus concluded that the choice of appropriate boundary conditions is critically important in the study of the energy conversion by magnetic reconnection. The present finding also points to the likelihood that the study of reconnection in two dimensions in a fixed boundary system may not reveal any appreciable magnetic field-to-particle energy conversion in an overall sense, although the present idealized theoretical approach cannot address the possibility of local heating and acceleration. This does not necessarily mean that the energy conversion by reconnection is not an efficient source of particle energization, for in nature the system is not limited by any artificial boundaries. The present finding instead only points to the possible limitation of studying the reconnection by a two-dimensional fixed-boundary system. (c) 2006 American Institute of Physics.