Critical Current of the Ionization Waves and Anomaly of the Positive Column in an Axial Magnetic Field

Abstract

l'iiivrrrity. 992 Toiir7awa, .lapan Crit,ical Current of the Ionization Waves and Anomaly of the Positive Column in an Axial Magnetic Field M. SATOInflucnces of an cixiol magnetic field on the ionizntion wive and the positive column in rnre gas discharges nre studied experimentally. The upper critical current I, for the appearance of ioni. zation waves in the magnetic field B is newly found. A s B is grodually increased, the value of I, slightly increases from the Pupp's vnlue nnd after passing 21 prominent maximum, finally become very smnll. In nddition an unoninly takes plnce in the axial electric field B of the positive column 3tnhle for helit-a1 instabilit.ies. With incrensing the mngnetic field the vnlue of E goes through n weak niiiximuni bcfore decrensing. It is concluded that this nnomaly. apparently incompatible with clndnicnl diffliaion theory. is c4osel.v relnted to the appeiiriinw of ionization wiives in the positire coliimn .