CURRENT SHEET FORMATION ALONG 3-DIMENSIONAL MAGNETIC SEPARATORS

It was shown by Syrovatskii [Sov. Phys. JETP 33, 933 (1971)] that a pe rfectly conducting two-dimensional magnetic field stressed externally develops a current sheet at an X point. A generalization of this analy sis shows that a generic three-dimensional magnetic field develops a c losed ribbon of current along separators already existing in the field . A separator is a field line that begins and ends at different magnet ic null points. A current ribbon will occur if there are two distinct separators beginning and ending at the same two nulls, thus forming a loop. The magnetic field containing the current ribbon is in force-fre e equilibrium. An expression is found for the net current induced in t he ribbon, and the magnetic energy stored by it, in terms of the amoun t of external stress; An electric field parallel to the current will f acilitate reconnection and will dissipate the current and release the stored energy. (C) 1996 American Institute of Physics.