MAGNETIC-FIELD LINE RECONNECTION IN STRUCTURALLY UNSTABLE MAGNETIC CONFIGURATIONS

The transformation of structurally unstable magnetic configurations in to structurally stable ones is studied both analytically and numerical ly. This transformation, which is forbidden in the ideal magnetohydrod ynamics, is shown to occur in the process of magnetic field line recon nection. The regions near magnetic null lines of high orders are exami ned. Azimuthally symmetric perturbations are shown to cause the format ion of a finite-size current region bounded by magnetic separatrices. It is shown that, as a result of asymmetric perturbations, con figurat ions involving current sheets with different polarities arise at magne tic separatrices.