C. Avram et al., Current jumps and hysteresis in a single-ended Q-machine in connection with the electrostatic ion-cyclotron instability, CONTR PLASM, 39(3), 1999, pp. 223-233
We report on an investigation in a single-ended Q-machine where the current
-voltage characteristic of a small collector showed some interesting new fe
atures. The most interesting of these was a sudden jump of the current at t
he onset of the electrostatic ion-cyclotron instability. This jump was also
accompanied by hysteresis. Besides that, the characteristic showed another
trivial type of hysteresis that was only due to a temporary covering of th
e collector by alkaline metal from the plasma. The former phenomenon could
be an indication that the well known nonlinear potential structures that ap
pear periodically in front of the collector during a cycle of a high-amplit
ude electrostatic ion-cyclotron instability, are related to inelastic colli
sions of accelerated electrons with alkaline vapour present in the plasma c
olumn.