Ionization instability

An ionization instability is any one of a category of plasma instabilities which is mediated by electron-impact ionization. In the most general sense, an ionization instability occurs from a feedback effect, when electrons produced by ionization go on to produce still more electrons through ionization in a self-reinforcing way.

Ionization instabilities have been seen in such plasma physics apparatus as glow discharges, Penning discharges, magnetic nozzles, and MHD generators. Ionization instabilities may occur in magnetized or unmagnetized plasma. They occur mostly when the plasma is relatively cold and only partially ionized, so that there is a lot of neutral gas mixed in with the plasma.