Some phenomena during electric discharge ignition in long tubes

Phenomena in slow nonlinear ionization waves are propagated under the action of changes in the electrode potential in discharge tubes. It is well known that the motion of such waves is accompanied by potential redistribution along the tube with a substantial role of charging its walls. The experimentally observed independence of the ionization wave velocity on the induction of the applied longitudinal magnetic field is discussed. In the case of the strong magnetization of electron motion, the radial current on walls is admittedly connected with the loss of axial symmetry in the ionization front. The cause of this may be the development of the ionization instability of discharges in crossed E, B fields. Evaluations of the average number of ionizations induced by one electron in the zone of the potential jump before its drift on the wall are given at the negative polarity of the ionization wave for helium in the pressure range of 33–840 Pa.