ELECTROMAGNETIC-INSTABILITY AND ANOMALOUS RESISTIVITY IN A MAGNETIC NEUTRAL SHEET

An electromagnetic instability in a magnetic neutral sheet is investig ated by means of a two-and-one-half dimensional (21/2-D) semi-implicit particle simulation code. Electromagnetic waves are excited slowly in a field null region after saturation of the lower hybrid drift waves excited in an early time on both sides of the neutral sheet. This inst ability is found to be a new instability, independent of the lower hyb rid drift instability. Examination of its characteristic properties in dicates that the new instability is highly related to the meandering m otions of ions in the neutral sheet. The growth of the instability giv es rise to anomalous resistivity in the neutral sheet current. (C) 199 6 American Institute of Physics.