  An alternative explanation to the mechanism behind self-sustained
oscillations of ions in direct current (DC) glow discharges is provided. Such
description is distinguished from the one provided by the fluid models, where
oscillations are attributed to the positive feedback mechanism associated with
photoionization of particles and photoemission of electrons from the cathode.
Here, oscillations arise as consequence of interaction between an ion and the
surface charges induced by it at the bounding electrodes. Such mechanism
provides an elegant explanation to why self-sustained oscillations occur only
in the negative resistance region of the voltage-current characteristic curve
in the DC glow discharges. Furthermore, this alternative description provides
an elegant explanation to the formation of plasma fireballs in the laboratory
plasma. It has been found that oscillation frequencies increase with ion's
surface charge density, but at the rate which is significantly slower than it
does with the electric field. The presented mechanism also describes
self-sustained oscillations of ions in dusty plasmas, which demonstrates that
self-sustained oscillations in dusty plasmas and DC glow discharges involve
common physical processes.
