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,[1][2] Penning discharges,[3] magnetic nozzles,[4][5][6] and MHD generators.[7][8][9] Ionization instabilities may occur in magnetized or unmagnetized[10] 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.