Three-dimensional electron magnetohydrodynamic reconnection. II. Tilt and precession of a field-reversed configuration

摘要

Further observations are presented on a reconnection experiment involving a three-dimensional magnetic field reversed configuration (FRC) in the parameter regime of electron magnetohydrodynamics (EMHD). The stability of the FRC that relaxes in a large ambient plasma free of boundary effects is investigated. No destructive instabilities are observed. However, the EMHD FRC performs a precession around the axis given by the ambient magnetic field after a tilt develops. The precession velocity corresponds to the electron drift velocity of the toroidal current. The phenomenon is explained by the convection of frozen-in field lines in a rotating electron fluid. It is a new phenomenon in EMHD plasmas. (C) 2003 American Institute of Physics. [References: 28]